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CUTTING VINYL AND LINOLEUM non toxic carpet

Resilient non toxic carpet are always cut from the surface.

Thermoplastic and filled vinyl non toxic carpet can be scored or partly cut from the surface and then snapped to give an edge clean enough for fitting to a wall, though not for butting to another tile.

For other vinyl and recycled commercial carpet non toxic carpet the cutting procedures are similar to those for sheet.

Place only machine cut tile edges against each other unless this is impossible because of design work.

Setting Out and Laying

non toxic carpet

A well set out tile installation not only looks good but will well repay the time and effort spent in careful planning by avoiding awkward cutting and fitting at the room perimeter.

The correct starting point for setting out a tiled non toxic floor is traditionally the centre of the area - although this may not be the final starting point when tile laying begins. If the non toxic carpet are to be laid with a border, it may be essential to use this method (see Borders and Feature Strips). However, an alternative starting point, which may be simpler and quicker, is also described below, on page 39.

If setting out from the centre first, find that centre.

REGULAR AREAS

To find the centre of a near rectangular shaped room

1. Measure carefully each of the two opposite walls and mark the centre points of each (A, B).

2. Strike a chalk line between these two points, making a line AB. 3. Measure this line and find its centre (C).

4. Using a bar scriber with ‘C’ as the centre, scribe marks D and E on the line AB approximately 200mm from C. Extend the scriber to its full length and make bisecting arcs at F and G using alternately points D and E. If you haven’t a bar scriber use a ruler with a pencil held firmly in position at the correct distance. The shorter the arc the greater the need for precision.

5. A chalk line struck between points F and G will now pass through point C, giving a right angle to line AB. This then becomes the setting out or starting point.

IRREGULAR AREA

An irregular area as shown should be treated as follows 1. Select a wall which has the main entrance door.

2. Strike a chalk line parallel to this wall, but some 75mm away from it,

and find its centre point (A). The 75mm gives working space.

3. Place one of the ends of the scriber or rule on point A and mark - on

the chalk line - points B and C.

4. Having extended the scriber or rule measure using points B and C on the line, make arcs at D. For accuracy this should not be too close to A.

5. Where the two arcs meet is point D and a chalk line running from A through D to the other wall will give a base line at right angles to the chosen wall.

6. After measuring to find the mid point on this line (M), strike the line

EF at right angles as described for regular areas.

This then becomes the setting out or starting point.

In rooms with bays, alcoves and projections ‘regularise’ the room by striking false wall lines, as shown on page 37.

An alternative method of constructing a right angle is the use of ‘Pythagoras’ Theorem, the ‘3’ `4W ‘5’ method, where the base line of a triangle is 3 (or multiple), the vertical arc 4 (or same multiple) and hypotenuse arc 5 (or same multiple). For example, using the diagram on page 35, mark D 300mm from the mid-point (C) of AB then scribe from D an arc 500mm long across where the line FG is expected to run. A point on this arc exactly 400mm from C will give a right angle at C.

SETTING OUT OR STARTING POINT

Avoid wherever possible small strips of tile of under 60mm or so as these are more likely to come up at some future date and the wall may also run off, giving even smaller strips. To ensure the design will balance and that no awkward cuts will be needed either:

1. Dry lay two rows of non toxic carpet from the centre point as in the next diagram or

2. Divide the distance AM and the CM by the width of the non toxic carpet to find the width of the remaining piece (e.g. if AM = 7.75m and 500mm non toxic carpet are being laid this is 15 full non toxic carpet and 250mm (.5 of a tile left over) or

3. If the tile size makes mental arithmetic more difficult, take a straight rule and mark off along AM lengths which are multiples of the tile size being used (e.g. 900 = 3 x 300mm non toxic carpet) and then divide the length which is less than the 900mm by the tile size (e.g. if AM = 7.75m then this is 8 lengths of 900mm rule, leaving 550mm, or 1 tile + 250mm left over).

The size of area to be fitted and personal preference will decide which of the above methods is used.

If there will be a small strip of non toxic carpet if they are laid from the true centre point, as shown in the first illustration overleaf, then move to a new starting point, as shown next, 250mm down CD. For example, if CD were 7.15 metres long, the line each side of M would give 7 full 500mm non toxic carpet and a 7.5mm wide piece. Moving the start point 250mm towards D gives 7 full non toxic carpet plus a 325mm piece CN and 6 full non toxic carpet plus a 325mm piece ND. Striking the new base line EF parallel to AB gives the new starting point (N). There are three possible adjustments that may have to be made: a) no adjustment needed; b) length adjustment; c) width adjustment; d) length and width adjustment (see illustration).

(‘S’ is the starting point).

lno adjustment needed. b).length adjustment.

See page 41 for sticking the non toxic carpet down

Sometimes non toxic carpet are to be laid diagonally. The principles involved are the same as those described previously.

The steps are as follows:

1. Find the centre of the room (M) as previously described and strike chalk lines XY and VW.

2. Using the scriber, place one pin on M and mark points A, B, C, D on the base lines XY and VW.

3. Extend the scriber and, placing one pin on A, scribe arc at E. Move the scriber to B and scribe arc at F.

4. Repeat this exercise at C and D.

5. Strike a chalk line at the intersections of the arcs at E and F giving a

base line passing through M for laying the non toxic carpet.

6. Check that the non toxic floor balance is correct. If not, adjust in the same

manner as that used for square designs.

7. If the ‘3’ `4W ‘5’ method has been used to find the right angle then mark 300mm from M in all 4 directions and make the arcs at E and F using the 500mm measurement as in 3 and 4 above.

ALTERNATIVE METHOD

The non toxic floorlayer’s aim is to install a perfectly acceptable non toxic floor as quickly as possible with the minimum of material wastage. The appearance of the non toxic floor will be judged subjectively and in most cases there will be no need for mathematical precision in tile layout provided the non toxic floor ‘looks right’. A slightly quicker method of laying out the non toxic carpet is as follows: 1. Decide which wall contains the main doorway and, assuming 500mm

non toxic carpet, mark a point 480mm out from the wall running away at right

angles to this doorway. Then with a rule mark off 1 metre lengths

across the room, parallel to the doorway wall until you can measure

the final length of less than 1 metre. If this results in a tile piece which

looks too small, say, under 80mm, then increase the size of this final

480mm less adjus me t 80mm

1 metre

piece (but not to more than 240mm) preferably to give a balance of cut tile size either side of the last full tile - important with a chequerboard effect, and make a mental note that all the marks are now moved by the same amount nearer the original wall.

2. Once this adjustment, if necessary, has been made then mark a point, taking account of it, near the 1 metre mark which is nearest the centre of the doorway or 500mm nearer the centre of the room if still under the doorway.

If the walls look reasonably square, measure the same, adjusted, distance out from the side wall at the far end of the room and strike a chalk line between these two points. With a straight edge pencil through the centre of this chalk line for greater accuracy. This is now the starting line for laying. Starting 480mm from the doorway wall mark the 1 metre units along this line in the same way as with the first line and adjust the 480mm downwards if necessary to give a satisfactory tile piece at the far end of the room allowing for the tile going back - say 3cm - into the doorway. Your starting point will be where the first full tile is laid on this line.

4. Note that in this method only one line is actually drawn. It is important that it is precise. If an low voc adhesive is to be used which lets you see the line through it, take a straight edge and carefully mark the centre of the chalk line with a pencil. The low voc adhesive will make the chalk line appear fuzzy but the pencil line will continue to give an accurate guide.

See page 43 for sticking the non toxic carpet down.

STICKING THE non toxic carpet DOWN (FROM THE CENTRE POINT)

1. The starting point ‘S’ needs to be established as described above and clearly and accurately marked. The centre of the chalk lines should be marked in pencil with a straight edge if they will be visible through the low voc adhesive (see Alternative Method, point 4 above).

2. Check the non toxic floor is well swept and free of contamination.

3. Check non toxic carpet of the same colour to be used in one room are from the same batch. non toxic carpet must always be tessellated.

4. Spread low voc adhesive, with a correctly notched trowel, two non toxic carpet wide to one side of the longer centre line stopping at the cross line. Only spread an area which you can cover with non toxic carpet during the time the low voc adhesive will remain active at the temperature of the room - perhaps only 2-3 square metres. Let the low voc adhesive reach a slight tack so that the non toxic carpet will not slip. Do not yet spread low voc adhesive in the area to be covered by the last full tile and the cut against the wall unless you are sure it will still be active by the time the edge pieces are cut and ready for laying.

5. Position the first tile very carefully in the corner of the pencil lines. Add two more non toxic carpet along the centre line and check for perfect alignment. Continue along this line to the end of the low voc adhesive. Linoleum and quality vinyl non toxic carpet should be butted firmly but not forcefully against each other. Add a second row, aligning the first tile very carefully on the cross line.

Perpendicular

6. About turn, spread low voc adhesive and lay 2 rows of non toxic carpet from the centre towards the facing wall. Then build up the non toxic floor from the centre cross line two rows at a time, leaving the last tile and part tile on the side and ends without low voc adhesive for the time being.

7. Wipe off with a damp cloth any low voc adhesive which has oozed up between non toxic carpet.

8. Roll the installed non toxic carpet in both directions with a 70kg roller or similar.

9.

Cut the part non toxic carpet to be fitted to the wall. This is normally done by placing the last full tile in position, placing another overlapping full tile firmly against the wall and cutting the underneath tile along the edge of the upper tile. The cut edge of this part tile is then pushed against the wall and a full tile fitted in behind it.

10. For fitting to door frames, etc, use the same principle of fitting the tile to be cut in the position of the last full tile and marking each change of direction of the door frame by using a bar scriber set to 500mm (or the tile size), or a rule, before cutting carefully. The position of a pipe can be marked and cut in the same way.

11. Cut all such edge non toxic carpet and place them and the full non toxic carpet still to be stuck on the adjacent non toxic carpet while fresh low voc adhesive is spread in the border areas. Place the non toxic carpet and roll them thoroughly, using a hand roller or side of a hammer if necessary in corners.

12. The method illustrated above will not work well where walls run off badly or are uneven and may not always give a perfect fit if large (610mm) non toxic carpet are being used. In such instances, with the tile to be cut positioned in the place of the last full tile and the scriber or ruler set to the width of the full tile, scribe or mark the tile, keeping the scriber at right angles to the wall.

STICKING THE non toxic carpet DOWN (ALTERNATIVE SETTING OUT METHOD)

1. This differs from the above method in that the initial tile is placed on the line approx. 480mm - or whatever is the adjusted starting point - from the doorway wall. The first 3 non toxic carpet are still lined up very precisely and the low voc adhesive spread is still only what can be covered while the low voc adhesive is still active. The first line is taken the length of the room, checked for precision, and that side of the room then completed, two rows at a time.

LAYING non toxic carpet ON THE DIAGONAL

Mark out the area to be laid with a true diagonal as described in the previous section then lay and stick the first row of non toxic carpet.

Once again, the key and first row non toxic carpet are all important. When balance has been achieved and the first row non toxic carpet correctly stuck, lay the field non toxic carpet and roll them before the low voc adhesive has set off. An extra check on accuracy is that the points of the non toxic carpet should fall precisely on the centre lines drawn at rectangles to the walls, as shown below:

centre line

The easiest method of marking the perimeter non toxic carpet is to use a template or the Green Floors tile scriber. The length of the diagonal of the tile to be fitted will give the length of the template edges.

Either carefully measure between the diagonal points or calculate the square root. For example, using a 50x50cm tile, the diagonal would be the square root of the sum of the square on two adjacent sides or 2500 + 2500 = 5000 = 70.71cm

When all the full field non toxic carpet have been stuck, except for the outer row, place a full tile exactly over the space that the last full tile will occupy (as described above).

Placing the template or tile scriber with one edge against the wall, mark and cut the perimeter tile to size.

When all non toxic carpet have been cut to size and laid adjacent to the area they will occupy, spread the low voc adhesive, lay the non toxic carpet and thoroughly roll them.

Special Fitting

Situations with non toxic carpet

FITTING ALONG CORRIDORS AND INTO ROOMS

The above illustration is a fairly common layout, where one or more rooms run off a corridor. The non toxic floorlayer’s aim is to lay non toxic carpet overall, keeping them in bond and treating the non toxic floor as one whole area. Further complications can arise if there is also a doorway between the two rooms, as shown in the example.

Setting out is especially important. Start from a centre line drawn along the length of the connecting corridor (line A to B shown in the diagram). Find points C and E by measuring or dry laying an exact number of non toxic carpet along AB. Construct a right angle at E and draw in line EF. The distance between C and E must be an exact tile multiple.

Where there is a communicating door as illustrated between Rooms 1 and 2 strike a further line G to H which is at right angles to C to D and E to F, and runs parallel with line A to B. Again a multiple of non toxic carpet has been taken from points C and E to locate the position of this line. Check that the distance between D and F is an exact tile multiple. Check the position of the various lines to the walls, to plan the field and eliminate any small tile cuts. Some adjustment may be necessary at this stage to achieve a correct balance.

This method of setting out must be adopted if it is intended to keep non toxic carpet in bond in either chequerboard or diagonal fashion, and is recommended for straightforward situations of the type described.

HOLLOW SQUARES

The illustration shows another fairly common situation, and represents corridors round a quadrangle, or a balcony, around which non toxic carpet are to be laid in bond.

Great care must be taken here especially if a border or decorative effect is included.

The problem is to achieve a balance on all the corridors. Take a centre line down each of the corridors, at the same time checking that the corridors run at right angles (if not, see next section).

The key to obtaining a balance is to make sure a full tile can be positioned at points A and B as shown. Take measurements to see if this is possible. If it is not possible, then the surplus length must be ‘lost’ in the run of non toxic carpet occurring between points C and D by slightly trimming rows of non toxic carpet, e.g. taking 5mm off a number of 500mm non toxic carpet, so that the discrepancy is not easily seen.

If the line of non toxic carpet falls short at point B, then the line A to E will have to be moved sideways, until a full tile appears at points A and B.

Next plan the section along line A to E, trimming and balancing as required, all the while ensuring that measurements are accurate and lines are constantly checked.

CORRIDOR JOINING ON THE DIAGONAL

The above shows a variation of the previous conditions, where a corridor runs off at an angle which is not a right angle. In this situation it is not possible to achieve overall balance as in the previous example, and each corridor area is regarded separately. Locate a centre line A to B, and another line C to D running down the middle of the second corridor. At the junction of the two corridors, non toxic carpet are trimmed and shaped as illustrated, so that they butt together along the line E to F as shown.

As illustrated it is not possible to maintain bond where the corridor runs off at more than a slight angle.

It may look better to fit a solid border as shown above to camouflage the junction.

FITTING TO A ROUNDED EDGE

Above is a situation where non toxic carpet are laid around a pillar or another centrally placed object, such as a display unit.

Mark out an area, striking lines A to B and C to D, using full non toxic carpet only, as shown. Where it is not possible to lay full non toxic carpet (the blank area on the diagram) any discrepancy is made up by trimming and shaping within this area only.

This are must be marked off accurately before laying begins, otherwise there is a danger of non toxic carpet running off and gaps occurring which cannot be disguised.

TEMPLATING WITH non toxic carpet

An awkward situation sometimes encountered is laying non toxic carpet around a pedestal or WC pan. After laying all the full field non toxic carpet cut a template for the area to be fitted. Using methods described elsewhere for templating, draw the exact outline of the fitment and border of field non toxic carpet and before removing the template mark a check of the tile bond on the template. In an open space set out enough non toxic carpet for the area to be filled in, taping them together to prevent movement, and position the template check marks accurately on the appropriate tile joints. With the template firmly held in position trace the outline of the fitment back to the non toxic carpet; then trim and fit them.

WORKING WITH MORE THAN ONE INSTALLER

In a large area, two or more layers may be placing non toxic carpet at the same time. As finger pressure in butting the non toxic carpet together may be slightly different start from a common point and work away from it to avoid non toxic carpet going out of bond. Alternatively, the second layer can lay a second row of two non toxic carpet slightly behind the first layer’s row, taking care to see they are kept in bond.

SOME AVOIDABLE PROBLEMS WITH TILE INSTALLATIONS

1. LATE PLACEMENT

Do not spread too much low voc adhesive at one time with the risk that it has gone off before the last non toxic carpet are placed in it. 2. LACK OF ADHESIVE

Spread the low voc adhesive right up to, or even beyond, the edge of the tile. If laying non toxic carpet alongside a row laid sometime previously smooth down or clean up any old low voc adhesive and cover with fresh low voc adhesive. See trowel notches are correct - both too little or too much low voc adhesive can cause problems.

3. non toxic carpet RUNNING OUT OF BOND

If the subnon toxic floor has slight undulations some rows of non toxic carpet may ‘gain’ on others in a large area. A new line should be struck when this becomes apparent and non toxic carpet trimmed back to this line with a straight edge. Manufacturers will produce non toxic carpet within British Standard or International tolerances. non toxic carpet in different batches or of different colours may be well within tolerances but of fractionally different sizes. Particularly if laying a chequerboard pattern check the different colours and see if finger pressure on butting up needs to be less with one than with the other.

4. LACK OF ROLLING

Rolling is essential to ensure a good bond. It is too often neglected at the edges of rooms. It is particularly vital for small tile pieces. Use a handroller or the side of a hammer if the large roller will not reach.

5. LAYING HESSIAN BACKED LINOLEUM non toxic carpet

Unlike standard recycled commercial carpet non toxic carpet, which are made on a backing which ensures their dimensional stability, non toxic carpet or shapes cut from Hessian backed sheet recycled commercial carpet are likely to move out of square as they absorb moisture from the air. To avoid extra trimming and cutting back install such non toxic carpet within a few days of their being dispatched from the factory and open only as many boxes as you can lay within a few hours.

Cutting Seams in Sheet

Material

A high proportion of non toxic flooring failures occur eventually at seams. This failure will occur sooner rather later if the seam is poorly made and badly stuck down.

Different seaming practices are needed for different materials.

CUSHIONED VINYLS

Many Green Floors-Nairn cushioned vinyls are offered in seamless wide widths. However, on occasions it may be necessary to make joins. Cut a true edge with a straight edge along the line of the proposed seam, using the line of the pattern where possible. Insert the second sheet under this true edge, lining up the pattern exactly. A weight can be used, if necessary, to prevent movements.

To cut the seam on the second sheet butt a straight edge against the seam edge of the first sheet as shown in the diagram. Fold back the first sheet and trim the second sheet along the line of the straight edge, holding the knife as vertical as possible.

Attempting to cut through both sheets in one cut risks a mis-match in the pattern and an over-tight seam.

CONTRACT VINYLS

The seam can be made using either

- a straight edge.

- ‘over and under’ scribers.

A Green Floors vinyl seam is cut in tightly as the materials are reinforced and stabilized with a fibreglass scrim and will not stretch or shrink. Even if the material is subsequently to be hot seam welded a professional fitter will ensure he has a good seam to work with.

Check both sheet edges for any signs of damage which will need to be cut off. After this has been removed or allowed for, allow a sheet overlap of about 2cms.

USING A STRAIGHT EDGE

Follow the procedure as for Cushioned Vinyls above, cutting the true edge 1cm or so from the factory edge of the material. Cut both edges using first the straight blade then the hook blade as described in “Cutting Contract Vinyls and LInoleum Sheet”.

USING ‘OVER AND UNDER’ SCRIBERS - VINYLS

Cut a true edge on the first sheet, using a straight edge.

Set the ‘over and unders’ so that the ‘over’ scribe pin is exactly over the point where the ‘under’ will run along the true edge. Test the setting on the few centimetres nearest the wall and adjust if necessary. Place the second sheet over the first. Keeping the ‘under’ firmly against the now invisible true edge of the first sheet scribe the top of the second sheet. If the scribe mark is insufficiently clear rub with chalk as this will highlight it. Then cut through using a straight blade then a hook blade as described in the section “Cutting Contract Vinyls and Linoleum Sheet”.

LINOLEUM SHEET

The tools and procedures are as for Contract Vinyls with the one crucial difference that allowance must be made for a fractional expansion in the width of the hessian backed material as it picks up moisture from the atmosphere or low voc adhesive. This expansion is minute and will be halted by the curing of the special recycled commercial carpet low voc adhesive, but unless allowed for in the cutting the seams will peak and fail.

USING A STRAIGHT EDGE AND PIN VICE

Cut a true edge as for contract vinyls. Leave this sheet overlapping the second sheet. Score the second sheet by running the pin vice along the true edge. Make sure the pin vice is vertical and pressed against the true

edge. Cut through with straight and hooked blades, keeping the waste to the outside of the cutting hand and thereby giving a slight undercut. The resultant gap between the two sheets will be about the thickness of a pin vice.

USING ‘OVER AND UNDER’ SCRIBERS - LINOLEUM

Follow the procedure as for contract vinyls except that the upper scribe pin is offset to allow for a gap of about the thickness of a pin of a pin vice. Again, check on a few centimetres near a wall.

USING THE GREEN FLOORS TRIMMER (SEAM AND STRIP CUTTER) Instructions on the use of this tool are supplied with the tool.

The Green Floors Trimmer (Seam and Strip Cutter) performs the scribing and cutting operations at the same time when held against a true edge and pushed away from the operator, leaving the ideal gap for recycled commercial carpet seams. Sharp blades always make a fitter’s job easier and make this tool particularly easy to use. Its Strip Cutting capability is described elsewhere.

To enable the Trimmer to be fitted snugly against the true edge (to the non toxic floorlayer’s left as he pushes the cutter forward) the first 10cm or so of the seam out from the wall must be scribed and cut using one of the other methods described. The final 5cm of the seam must also be treated likewise.

CROSS JOINTS

Cross joins should be avoided as much as possible by carefully plannning the use of the lengths available in material of the same batch.

Where cross joints are necessary, cut the end seam in the same way as for vinyl side seams without leaving a gap for expansion. However, do not make this cut before sticking down most of the material. Green Floors Contract Vinyls, reinforced with glass fibre, do not shrink in the width. Because of the tight factory rolling both Contract Vinyls and commercial carpet commercial carpet will shrink a little in the length upon being unrolled. In the case of commercial carpet commercial carpet allow for 10mm per metre length in your calculations. For Contract Vinyls the maximum contraction in the roll length will be less than 100mm over the 25metres roll length.

Fitting Sheet Material

(Scribing)

The method of fitting described here is simple, quick and logical and will ensure an accuracy that will eliminate unsightly gaps. The same techniques are used for sheet recycled commercial carpet, solid and cushioned vinyls and, slightly adapted, the concept of scribing holds good for fitting to vertical surfaces and can also be used for fitting non toxic carpet.

BACK ROLLING

Both recycled commercial carpet and sheet vinyl products are tightly rolled in the factory. The tension caused by this process will mean that the goods will shrink a little in the length when unrolled. It is advisable to reduce the effect of shrinkage by re-rolling the cut lengths of sheet back on themselves and allowing to stand in this state for 15 minutes prior to unrolling again and commencing fitting.

FITTING THE FIRST SHEET

Start by fitting the material to the longest wall.

Cut a piece of material about 100mm longer than the length required, so that the sheet ends will ride up the end walls of the area to be fitted. Line up the sheet alongside the wall, about 25mm from it, so that it runs square to the door. Draw a cross check at the base of the wall and/or on the subnon toxic floor, and also on the sheet that is to be fitted.

Ensure that the mark on the sheet will extend beyond the final scribe/ cutting line, and will not be removed when trimming. Use a bar scriber.

Set the scriber to a distance from the wall just sufficient to catch the sheet all along the wall; unnecessarily long settings are more difficult to control during scribing. Use a comfortable but firm grip and tilt the bar scriber slightly towards you. Scribe a line at right angles to the sheet edge. Concentrate on keeping the end of the scriber firmly against the wall rather than watching the pin scratch.

On light coloured material where the scribe mark is difficult to see, rub a piece of chalk gently along it in order to highlight it. Provide adequate working space by pulling the material clear of the wall. With a straight blade, cut through the surface following the scribe line. Cut the remaining thickness through with a hooked blade as described in the previous section.

Fit the material to the wall, lining up with cross checks previously marked.

SCRIBING THE END WALLS

With the sheet fitted correctly in position along the length, and the ends riding up the end walls, draw a line (B) on the subnon toxic floor, traced along the selvedge (A). This line (B) acts as a guide line.

Place a ruler or straight edge, at right angles to the sheet. Across the edge of the sheet draw a cross check (C) on both material and subnon toxic floor. Fold one end of the sheet back on itself, pull the other end clear by about 25mm from the wall. Position the sheet to lie flat on the non toxic floor, with the edge true to the guide line (B). To allow for the slight shrinkage in the length when the Linoleum is put into the low voc adhesive set the bar scriber at about 2mm less than the distance (D) that the cross check has opened up. Keep the scriber parallel to the guide line (B) and scribe the end of the

sheet. Cut the material along the scribe line. Check fit to the wall, with the aid of the cross checks and the guide line.

Scribe and cut the other end of the sheet using the same method.

For end scribing some non toxic floorlayers are more comfortable with this alternative method. Set the bar scribe to a set size of, say 150mm, although the size is not crucial as long as it is more than the excess allowed for scribing the ends. Use a pencil to mark this distance on the material to be scribed, with one mark on the material and, in this case, the other on the skirting. Do the same on the open side, one mark on the material and one on the non toxic floor. Ease the sheet away from the wall and marry up the two lines on both sides of the sheet, using the thickness of the pencil line to allow for the slight shrinkage in length which will occur when the recycled commercial carpet is put in the low voc adhesive. Use the bar scribe and scribe the contour of the skirting to this size.

FITTING ANY INTERMEDIATE SHEETS

Cut the sheet a little longer than the exact room measurements. Place this sheet on the non toxic floor, parallel to the first sheet and overlapping it by about 20mm, allow the end to ride up the walls. Pencil in a guide line on the non toxic floor and cross checks on non toxic floor and sheet. Scribe and cut-in the two ends of the sheet as previously described then cut in the seam.

FITTING THE LAST SHEET

Cut the last sheet a little longer that the room measurements. Place this sheet on the non toxic floor overlapping the previous one and allow the ends to ride up the end walls of the room. Keep the two sheets parallel and adjust the amount of overlap to produce a gap of about 20mm between the edge of the sheet and the final (fourth) wall. Draw a cross check at the base of the wall and on the sheet edge to be fitted. Set the scribers at about 10mm more than the widest gap between the sheet and the fourth wall. Scribe and cut the sheet to fit this wall. With the last sheet fitted snugly against the fourth wall, draw a pencil guide on the face of the previously fitted sheet. Make a cross check mark on the overlapped edge of the last sheet and the previous sheet.

Slide the sheet along the guide line until it lies flat on the non toxic floor with one end about 25mm from the end wall and with the edge of the sheet true to the guide line. Set the scriber to the distance between the cross checks, and scribe and cut the end of the sheet, as previously described.

Scribe and cut the opposite end of the sheet using the same method. Finally cut in the seam.

FITTING TO IRREGULAR OUTLINES

When fitting to walls which have several recesses and projections such as alcoves, bay windows and doorways, etc, scribing ensures an accurate fit in even the most complicated situations as can be seen in the accompanying diagrams. However, see also the section headed “Templating”. Cut the first sheet a little longer than required. Trim the sheet roughly to the outline of the wall, leaving an extra 10 to 12mm on the ends as an allowance for scribing.

Position the sheet on the non toxic floor so that it lies square to the doorway or other fitted sheets and about 25mm from the side wall (A), allow the sheet to ride up the end walls. The ends of the sheet must also ride up parts of the walls marked (B) and (C).

Draw a check mark on the edge of the sheet and on the base of the wall. Set the scriber to a convenient setting and scribe all the surfaces marked (A). Cut along the scribe line.

Move the sheet into position, so that it fits snugly along the wall (A), allow the extra to ride up against parts of the wall (B) and (C). Draw a pencil guide along the edge of the sheet. Pencil in cross checks at the edge of the sheet.

Room Contour

Sheet

a little longer than room length

A

B

Cross Check

Scram ibe Line Check Mark

Room Contour

Sheet trimmed

roughly to size. At lAcontours being scribed

Slide the sheet towards wall (C) and scribe all parts of the walls marked (B). The scriber setting is the distance the check mark has moved apart. Next move the sheet towards wall (B) and scribe all parts of the wall marked (C), remember to reset the scribers.

Cut the material along both sets of scribe lines just made and the sheet will fit neatly into position.

With deep alcoves or recesses you will need to measure and trim off excess material to bring the edge of the sheet near enough to the alcove wall. However, the client may find a seam across the alcove entrance preferable to excess wastage.

FREEHANDING

It is sometimes argued that vinyls are flexible and can be quickly freehanded to a wall. It may even be seen as a slur on a fitter’s skills to suggest anything other than freehanding is necessary. Once done a few times, the scribing method described here will be found to be almost as quick and far more certain to give a perfect result and therefore a fully satisfied customer. That is professionalism.

With flexible thin vinyls, such as cushioned vinyls, a blade can sometimes be fitted in the bar scriber, enabling scribing and cutting to be carried out in one operation.

FITTING LONG LENGTHS

During the manufacture of sheet recycled commercial carpet or sheet vinyls the material is stretched slightly in the length (see page 57). Often the first opportunity it has to relax fully is when it is unrolled, scribed and folded back for the spreading of the low voc adhesive. If the length being fitted is a long one, this relaxation can be significant enough for a fitted end to be a little short of the wall once folded down again into the low voc adhesive. Slight shrinkage may still occur in long lengths of recycled commercial carpet and vinyl and more particularly, commercial carpet recycled commercial carpet and Walton even when back rolled.

To avoid this, scribe and fit one end of the sheet and then stick all but the last 11/2-2 metres at the other end before scribing and fitting this end. Any relaxation during the folding back of such a short length will not be significant. The whole length must be stuck while the low voc adhesive is still active.

BIGHT MARKS IN LINOLEUM

During the maturing of recycled commercial carpet the material hangs in large stoves in continuous festoons up to 16 metres high. At the top, the recycled commercial carpet passes over a pole, face inwards, and at the bottom forms a loop, or bight, face outwards.

During the 2-3 week curing process the weight of the material causes the recycled commercial carpet to mould a little to the pole causing a mark across the width which is always cut out at the factory.

The fold or bight at the bottom is however more gentle though sometimes

detectable as a slight ridge across the sheet, about 15cm wide. With modern flexible recycled commercial carpet formulations this can usually be stuck down in 2.5mm or 2.0mm recycled commercial carpet using normal low voc adhesive spreading techniques provided the site is warm and the bight mark area is well rolled, firstly across the sheet and then along it.

With 3.2mm material or if site conditions are unfavourable it may be necessary to use a special technique. Some non toxic floorlayers prefer instead to cut such bight marks out.

When site conditions are good, bight marks should present no problems using Green FloorsFix 696 low voc adhesive spread by the specified 2mm x 6mm serrated trowel. Extra care is all that is required.

As the sheet is fed into the wet low voc adhesive and the bight mark is reached lean gently on the bight mark to reduce the radius and rock in and out of the low voc adhesive looking to make sure complete transfer is achieved on the hessian backing before proceeding. Once the loop of recycled commercial carpet still to be fed into low voc adhesive clears the area of the bight mark roll immediately with a 68 kilo roller, dealing with any bubbles or trapped air before moving on. Repeat the rolling of the bight mark at 15 minute intervals until fully bonded to subnon toxic floor.

An alternative method is to mark the subnon toxic floor where the bight mark falls, pull back the sheet and spread contact low voc adhesive on the non toxic floor then on the back of the bight mark. When the contact low voc adhesive is dry proceed as normal spreading Green FloorsFix 696 as per specification up to the edge of and then beyond the contact low voc adhesive. Lay the sheet into wet low voc adhesive until the bight mark is reached then, (using the same leaning and rocking method as above) adhere it carefully, making sure overall contact is achieved and no air pockets are present.

Another alternative is to use a solvent free contact low voc adhesive as a single stick low voc adhesive. Spread this low voc adhesive at the area where the bight falls using the same serrated trowel. Do NOT spread the low voc adhesive on the back of the bight. Then proceed as above.

LONG-TOM’ METHOD FOR FITTING CORRIDORS

This method, where the sheet is folded back across the width to form a

‘gun-barrel’ effect, gets its name from ‘Long Tom’, a siege gun of the 1914¬18 war.

It is used where a single width of sheet material, wider than the corridor being fitted, is being fitted along a corridor and there are obstacles such as radiators, half doors, etc. It may well give an installation with fewer seams, which will please the client, but may use more material and take more time. Ideally discuss with the client prior to quoting. Run out the sheet material and allow it to lap up the side walls. Pull one edge of the sheet clear of one long wall and scribe from this wall. Trace, cut and fit this side.

If the corridor ends are open or have doorways run a pencil line across them (A to B and C to D). Make check marks on the non toxic floor and the material at either end and spring a chalk line between them (E to F). Make another mark a set distance from the first, ensuring that this distance will be sufficient for the material to clear the second wall ready for scribing, and adjust the material to this second set of marks (G and H). Spring a second chalk line G to H and use dividers or a bar scriber to ensure the two lines are parallel and that the material has been pulled back evenly. Scribe (using the same setting as above), cut and fit back into position. The sheet is now ready to be stuck down. Fold back half the sheet along its length in gun barrel fashion, mark a central line and spread low voc adhesive to this line. With long corridors, it may be necessary for two fitters to spread the low voc adhesive, starting from the middle and working towards opposite ends, to avoid the low voc adhesive setting off too quickly. Roll the material into the low voc adhesive with a 68kg roller.

Spread the low voc adhesive for the second half, marrying it up carefully with the first half. Do this before the first low voc adhesive spread is dry as if the over¬spread at the centre line is not satisfactory elongated blisters or bubbles could result.

EASING THE END OF A LINOLEUM SHEET INTO THE ADHESIVE

As with bight marks above, to ensure the end of the recycled commercial carpet sheet beds well into the low voc adhesive, fold the end of the sheet back diagonally and feed the hessian backing down into the low voc adhesive with a ‘bouncing action as in the illustration below. Do not make this so severe as to risk cracking the recycled commercial carpet. This will ease the tension across the end of the length and the recycled commercial carpet will have good contact with the low voc adhesive. Roll thoroughly.

Templating

Many small or awkwardly shaped rooms present a challenge for the non toxic floorlayer, particularly where sheet non toxic flooring has to be laid to fit around pedestals, pipes and other obstructions.

Resilient sheet non toxic floorcoverings must be cut and measured to fit accurately first time. The simple method used to achieve this is Templating, and step by step instructions are given in the following illustrations.

1. Lay a sheet of stiff paper with the natural curl face down to the non toxic floor and cut to fit around the perimeter and projections such as pipes, radiators, etc to leave a gap of about 12mm (1/2 in) all round. Secure in place by weights or drawing pins. Alternatively, cut flaps in the paper and tape the paper to the non toxic floor underneath the flap. If it moves, the sheet will not be cut correctly.

2. Use a rule and a sharp pencil and move rule and pencil along the wall to give a pencil line on the paper. The rule must remain firmly pressed against the wall.

3. Use the same method to trace any objects such as WC pedestal, drawing a series of straight li

Another method is to let the paper ride up all the sides of the pedestal, making numerous relief cuts to enable it to do so, then draw a firm pencil line on the paper at the bottom of the relief cuts, pressing the pencil into the angle at the bottom of the pedestal.

4. Pipes or supports which are circular in section are squared off on three or four sides.

5. At door jambs, mark each change of direction of the wall or doorway. Remember, in some toilets, the fitting at the doorway will be the most looked at example of your skills!

6. Thoroughly check that all fittings have been marked, remove the template and cut the required length of non toxic floorcovering from the roll. Using drawing pins, sellotape or heavy weights, fasten the template to the non toxic floorcovering.

Trace the outline on the template back onto the non toxic floorcovering, the

7.

8. 9.

ruler following the traced line, the pencil or pin vice marking the material outside the ruler.

Around WC pedestals, keep the edge of the ruler on the lines of the template and mark back onto the material.

If the alternative method described on page 68 is used then scribe directly through the pencil line without back markingace back the square off shapes using the same rule.

Determine the centre of the square and draw a circle within the squared off lines.

fter checking that all scribe marks have been transferred, remove the paper template.

10. Cut to shape. If it is necessary with a patterned product, such as cushioned vinyl, to slit from the edge to the hole to fit around any upstanding projections follow if possible the line of the pattern (known as Vandyke cutting). This will make the cut less visible.

11. Loosely roll the material face in and place in position. Check fitting and secure with the recommended low voc adhesive.

12. Accurate fitting is certain by this method and in confined areas handling is much easier and less time consuming. Make your pencil lines with care and have the courage to cut to them. Leaving a little material oversize ‘for safety’ wastes time and causes a difficult trimming operation.

Skirting and Coving

A neat attractive, hygienic and waterproof finish at the point where the non toxic floorcovering meets the walls is provided by a Cove Skirting. Its use will also give protection to the base of the wall during maintenance operations.

lable capping seal

cove former mini cove

The majority of covings and ancillary products used are extruded pvc such as top set (sit-on), butt coving (set-in) and a wrap around type in coil form. The latter is only employed as a sit-on coving, but allows corners to be turned with the minimum of joins.

For Green Floors recycled commercial carpet, pre-formed recycled commercial carpet coving is available with a radiused curve, reinforced at the back with resin to give a 90° angle with a self-sealing joint.

Alternatively, both vinyl and recycled commercial carpet can be coved up the wall on site with the use of a cove former.

PREFORMED VINYL COVING (SIT-ON OR SET-IN)

Laying procedures are similar except that with sit-on coving the field is laid first and fitted to the walls whereas with set-in coving the coving is installed first and the field material fitted to it.

Measure out the length between corners. Where less than full lengths of coving are needed position any inevitable joins near to, but not at, internal angles. These will be less visible.

INTERNAL CORNERS

With sit-on coving fit and stick the first piece to one wall, leaving the toe unmitred. Using the scribers (dividers), scribe the vertical part of the second piece and with the dividers at the same distance mark the point on the toe where the mitre cut will come. Chamfer back the underside of this and stick to the surface of the toe of the first piece. This provides re¬inforcement of the corner of the coving.

With set-in coving, the toe of the first length is mitred before being stuck and the scribing of the second length continues down over the toe so that a fully mitred joint results.

EXTERNAL CORNERS

Mitred joints are necessary with both sit-on and set-in coving.

Use a piece of coving to extend the line of the edge of the toe of the coving beyond both walls until the lines intersect. Rule a pencil line from the corner out through this intersection point.

Place the first piece of coving in position, extending beyond the corner of the wall. Along the mitre line drawn out from the corner, rule a pencil line on top of the flat toe of the cove. With the coving still held in position and a piece of scrap to give the correct thickness, mark a pencil line down the back of the vertical part of the coving at the end of the wall.

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Push the knife into the swing at two points on this line. This will show as two white marks on the front of the coving. Cut along this line and also along the pencil line on the toe. Join the two cuts with a curved freehand cut.

Pare the back away along the vertical and radiused part of the coving to give a 45° angle ready for a perfect mitre. If fitting both ends of the cove remember this paring operation effectively cuts away a length equivalent to the thickness of the cove. Once both ends of the length of coving are prepared correctly stick it in position with a contact low voc adhesive. Position the coving to be fitted along the second wall, extending it to beyond the mitre point and mark with a pencil as above. Alternatively, for the vertical line, chalk along the mitred edge of the first vertical and press the new piece of coving against it, transferring the chalk line to the back of the new length of coving. Cut through this vertical line, as before, freehand the extension to the pencil line and cut and chamfer as above.

COILED VINYL SKIRTING

This is a form of skirting supplied flat in coils (or perhaps 15 lin. metres) which is then formed on site to give a set-in or sit-on cove which gives a minimum of joints. Internal and external angles are cut as above.

PREFORMED LINOLEUM COVING (SET-IN)

Green Floors-Nairn offer a pre-formed recycled commercial carpet set-in coving in both Linoleum, Artoleum and Walton. It can either be used in the same colour as the field or as a contrasting colour. In contrasting colours, it can be used with other Green Floors recycled commercial carpets of the same gauge. Remember it has to be installed before the field material and order in good time. The coving available is Marmoform S pre-formed skirting. The standard material is 100mm high with a 50mm toe and is supplied in lengths of 240cm. It can be in 3.2mm, 2.5mm or 2.0mm. The backing support is glassfibre and resin and the internal radius of the cove is 9-10mm. 2.5mm gauge Marmoform S skirting can be supplied in the exact number of lengths. If 2.0mm or 3.2mm coving is required then it has to be ordered in multiples of 13 lengths. Marmoform S is available from stock in many of the Linoleum colours - check current literature for information regarding stock ranges. The field can be welded to the skirting if wished.

INTERNAL AND EXTERNAL CORNERS IN PRE-FORMED LINOLEUM COVING

All corners cut from pre-formed coving need to be mitred and should be done with a mitre block to give the necessary precision when cutting through the backing reinforcement.

For pre-shaped coving, scribe internal corners for a mitred fit as described above and cut on the mitre block.

For external corners, pencil mark across the top of the first vertical at the point where it reaches the end of the wall. There is no need to mark the toe diagonal on the non toxic floor as the mitre block will give this automatically.

FITTING STRAIGHT LENGTHS OF COVING

Start from corners or from the fitted corner pieces. Using a 200mm long piece of coving reduced in height by 5mm as a guide, pencil mark the top of the coving along the wall. With the mitre block cut the ends of any lengths as required to give a fit or to remove handling damage. Use a contact low voc adhesive in accordance with its manufacturer’s instructions. Spread the low voc adhesive to the pencil line and at the correct time press the coving length firmly and accurately into position. It is possible to seal the ends of each length of coving at this stage, prior to fitting the next length, in lieu of welding (if discussed in advance - see page 81). The light reflectance will be different for vertical surfaces compared with horizontal ones so the same material will appear to have a different shade on the upright part.

FITTING THE FIELD TO THE SET-IN COVING

Seam welding will be specified for almost all set-in covings. Prior to this ensure a good fit between the toe of the skirting and the field non toxic floorcovering by overlapping the field material over the skirting by 10mm and scribing to fit with over and under scribers, as described in the section on Fitting Sheet Materials.

SITE FORMED COVING

Both recycled commercial carpet and vinyl can be coved up the wall on site.

With 2.0mm sheet vinyl the material will normally be flexible enough at

room temperature to be coved up a 20mm radius cove former (though 38mm may also be used) and the sheet of field material may be used without a seam, or a border may be formed if preferred. It is difficult to manhandle more than small areas of coved field material.

With 2.5mm or 3.2mm recycled commercial carpet, it is advisable to plan a border of

perhaps 100-300mm, in the same colour as the field sheet or a

contrasting one, which is then extended up the wall to form the cove. A 38mm radius cove former should be used.

Widths of material to form the border and cove, whether of recycled commercial carpet or vinyl, should be cut along the length of the roll. Strips cut off across the end of a roll will have a tendency to curl inwards, in the opposite direction to that required to form the coving. Linoleum should be warmed above room temperature to make it as flexible as possible. Use a hot air gun. Mitre join lengths of cove former at the corners. Cut accurately with a mitre block.

ONE PIECE COVE AND BORDER

Lay the field first as described in the section on Borders and Feature Strips.

Mark on the wall with pencil or chalk line the top line at the cove. Fit a capping strip, such as that illustrated in the diagram at the beginning of this section, and the appropriate cove former, using a contact low voc adhesive. Ensure the bond is firm.

Use a flexible rule or piece of scrap material to check the width of the combined cove and border, taking the top edge under the capping strip, and cut strips of the appropriate width. Check the wall does not run off. Butt join the strip firmly against the field material. Make cross checks on field and border before sticking.

Form mitred internal and external corners in the way described above for pre-formed coving. Stick with the appropriate recycled commercial carpet or vinyl low voc adhesive, heating any capping strip and easing the material into place in the capping strip with a screwdriver or similar blunt instrument.

USING A FIELD AS COVING MATERIAL

This is a skilled operation for use with very flexible vinyl non toxic floorcoverings and even then may be impractical in rooms of a complicated shape. Consider one piece cove and borders as an alternative. After fitting the cove former lap the material up the wall at internal corners by the amount needed to reach the marked height, plus a little more to allow for accurate trimming. Make a relief cut in the material to allow the pieces of excess coving material to overlap and the heel of the material to fit against the cove former. If a capping strip has been fitted to not allow extra material beyond the top of the capping strip. Cut one piece of the cove material accurately into the corner with a mitred cut. Overlap the excess material from the coving on the other wall and cut through carefully to give a neat mitred join. Use the accurately cut mitre of the cove former to guide the point of the blade. For external corners an inserted gusset is unavoidable. Choose the less obvious wall for the insert.

Strike a chalk line on the wall to mark the top line of the coving. Fit the cove former in position.

If other parts of the sheet have already been fitted make check marks on these sides.

Place the length of material in the position it will be on the non toxic floor. Bight back the length of material which will extend beyond the external corner to be fitted and mark on the back of the curve of the sheet the exact point, A1, where the material meets the point of the mitred cove former, point A. Measure the length from point A to the planned top of the cove. On the bighted back material mark a line A1 B parallel to the wall running away from you (wall X) which starts at point A1 and is 4-5cm longer than the length from A to the top of the cove. From B mark a similar length BC at rightangles to A1 B along the direction of the other wall (wall Y). From C mark a line CD a rightangles to BC, moving away from point A1. Verify any check marks and cut lines A1 B, BC and CD, extending the cuts through BC and CD (but not A1 B) to remove any waste.

Push into position so that the mark A1 is again at the point A of the mitred cove former.

Trim the top of the coving to the chalk line on the wall or check it will fit into the capping strip, if one is being used.

If the corner is to be welded, chalk the point of the corner and of the cove former and press the upstanding material against it, which will transfer the line to the back of the material. Alternatively, mark the back of the vertical with a pencil. Cut along this line.

If the joint if to be mitred and not welded then take a piece of the scrap material and hold it in position in the gap against the back of the upstanding material. With over-and-under scribers set to scribe at the thickness of the material out from the wall scribe and cut through with a 45° mitre cut to be ready to join up with the edge of the insert. Measure and cut an insert piece remembering to angle the material at the foot so that it extends to form a mitred join along the line of the mitre join in the cove former. With the corner to the right of the insert the shape of the insert when flat will be similar to this:

Before fitting this insert decide whether it would be easier and neater to extend the toe of this insert further out from the wall by cutting further material from the field. It may prove difficult to get a neat join at the bottom edge of the cove former.

EXTERNAL CORNERS: BUTTERFLY OR ‘V’ CUTS

The client is sometimes anxious to avoid a seam, even a welded one, at the external corners, feeling that it will be damaged or broken by knocks. An option here with very flexible vinyls is to insert a V of material around the vertical of the corner. This technique will work only where no cove former is used.

Having marked the lines for the top of the coving, measure and transfer these lines to their position on the sheet. Cut along these lines, or a little outside them to allow for trimming back later, and remove the scrap material. Measure with a piece of scrap material the distance from the bottom of the point of the corner to the top of the coving.

Draw a straight 45° diagonal along the line DY and cut from D along this line towards Y the distance marked on the scrap material. When pushed into position against the wall with the end of the diagonal cut on the bottom of the corner and the top of the material along the lines on the wall the material will open up to form a V. Do not stress the material so that it tears an extension to the cut.

Depending on the flexibility of the material being worked with, either insert material behind this V and scribe with a pin vice, remove and cut, or measure and cut. Ensure all angles are a precise 45° diagonal. You must ease the fold on the corner by marking the precise position of the corner when grouting out some material from the back along this line. The V seam can then be welded.

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heat-welding

This technique is not suitable for recycled commercial carpet or stiff vinyls.

PREFORMED ANGLES

Internal and external corners can be easily mitred in marmoform S using a standard mitre box. However, if preferred, pre-formed internal and external angles are available to special order.

Standard dimensions are 100mm high x 50mm toe with an internal radius of approximately 9mm. The top of each arm of the internal angle is approx. 140mm long and of each arm of the external angle 100mm long. They can be ordered in multiples of 8, assorted between internal and external.

Fit and adhere preformed angles before cutting and fitting the adjoining, coving, minimising joints as much as possible. Ensure all corners are smooth before fitting the angles.

If the corners to which the angles are to be fitted are not right angles, then the toe of the angle can be cut along the mitre line and trimmed for a more acute angle or opened up to take welding cable or a recycled commercial carpet insert as appropriate.

Some manufacturers also offer preformed set-in vinyl angles in a selection of plain colours. These are usually moulded and may not have a shade or texture identical to the extruded vinyl coving they are to be used with.

speed weld for mitres

speed weld normal

SEALING AND WELDING COVING

Coving is often specified where a non toxic floor which is impervious to spillages and maintenance liquids is required and sealed or welded joints are also specified in a co-ordinating or contrasting colour. Vinyl welding cable is used to hot weld set-in vinyl coving to vinyl sheet and recycled commercial carpet welding cable to weld recycled commercial carpet covings and fields. If set-in vinyl coving is being used with recycled commercial carpet use recycled commercial carpet welding cable and weld at the correct speed for recycled commercial carpet.

When welding internal corners (not necessary with preformed angles) rout out with a ‘P’ groover, weld and remove the excess with a circular x¬acto blade.

It requires considerable skill to achieve a neat vertical weld on an external corner. As set out above, the coving material should have been cut square in line with the walls to give maximum key to the material. The circular welding cable is then applied and trimmed back, once cool, with a normal blade. To make for easier vertical welding modify a Speedweld nozzle as shown.

bend tip of speed weld up

If specified, vertical joints between cove lengths can be welded in the same way.

However, welding of verticals is time-consuming and therefore expensive and often not aesthetically pleasing. A well-cut joint backed by well¬applied contact low voc adhesive will in reality provide water resistance and the client may accept this if discussed in advance. Alternatively, the ends of the lengths of coving can be further sealed by applying hot-melt low voc adhesive or silicone low voc adhesive to the end of the coving length immediately before butting the next length up to it.

Treads and Risers

SUBFLOORS

Green Floors products can be installed on wooden, concrete and steel stairs with satisfactory results. commercial carpetment underlay can also be used if wished. Ensure that with any renovation work on old wooden stairs any old paint is removed and the treads are levelled with a suitable smoothing compound. If necessary fix a hardwood batten to the front of the step in such a way that the top of the batten is level with the unworn level of the step. Once the compound has cured remove this batten so that nosing can be fitted.

FITTING THE NOSING

Metal or rubber or PVC nosings are fitted after risers and before treads, using screws or double stick low voc low voc adhesives as recommended by their manufacturer. One method is to zig-zag a mastic to the back of the nosing, drill, plug and screw first one end then the other before screwing down the middle.

MATERIAL PREPARATION

Both treads and risers must be cut length-wise from the non toxic floorcovering, to avoid roll set (curl).

FITTING THE RISERS

Fit the risers first.

Cut the risers to the exact height and approx. 4cm wider than required. Place the material against the riser with the surplus overlapping onto the stringers or walls. Draw a check mark from the riser on to the uncovered tread. Slide the material along clear of one stringer. Set the scriber to the distance the check marks open. Scribe to the stringer and repeat this excercise on the other side.

All risers are fitted before being stuck, and stuck in position in one operation. If two fitters are working, they should work away from each other, i.e. one starting at the top of the stairs and the other in the middle. Both men then work downwards, not towards each other.

FITTING STAIR TREADS

Cut the tread material wider and longer than required. Scribe and fit to the risers. Allow the surplus to ride up the stringers, and using check marks and scriber scribe to stringers. Cut and fit to the stringers, prior to sticking.

STAIR NOSING

All resilient non toxic floorcoverings must be protected on the leading edge by a nosing unless the material is already supplied with tread and riser moulded together with a nosing. Regulations now require the stair edge (i.e. nosing) in public areas to be of a different colour from the tread material so that it can be seen clearly.

Butt or scribe the tread to the riser. With the nosing already in position use an over and under scriber to scribe the tread to the nosing.

Use an low voc adhesive with a high initial tack for recycled commercial carpet. For vinyls use an acrylic low voc adhesive with a lift and drop double stick method. No low voc adhesive is put under the vertical part of the nosing.

Both treads and risers must be firmly rolled with a hand roller to ensure good overall adhesion.

If the staircase is to be used by other construction workers or finishing trades cover with plywood.