Fixed to Endure

01 Apr 2010 CW Team

In the 33rd in a series of clip-and-keep practical construction tips, Engineer Jagvir Goyal discusses aspects of marble and tile flooring.

1.While installing marble flooring, lay it over a ½-inch-thick bed of 1:3 cement mortar. Add polymer adhesive to the mortar for better grip. Use a liquid adhesive; Fevimate is excellent. For correct use, mix 1 kg of the adhesive with 20 litre of water and stir well. Add this solution to dry mix of cement and sand till you get a uniform mortar. Spread this mortar on the base, comb it with a notched trowel and fix marble slabs over it. When adhesive is used, cement mortar used may be 1:5 instead of 1:3. Thus, part of the cost of the adhesive is recovered. See that no air gaps are created below the marble slabs by any unevenness of lean concrete or mortar. Select skirting pieces from end pieces of marble. This will ensure that the skirting and flooring will match and look beautiful. Use long pieces of skirting for minimum joints.

2.While laying flooring in rooms, prefer to maintain dead level of floors. Provide a slope of 1 in 70 in bathrooms, toilets and kitchen towards the floor trap. In verandas, provide a slope of 1 in 70 towards the outside. As marble soaks moisture, always keep the top level of the marble flooring flush with DPC. If it is laid at a higher level, it will soak moisture from the sand below and pass it on to the walls. Don't let anyone walk over the marble for at least seven days.

3.To fix marble on the walls, the same adhesive used for the marble flooring can be used. However, for walls, keep the cement sand mortar at 1:2 ratio. You can also choose an epoxy-based, non-shrinking and non-staining adhesive. Such adhesives provide bonding strength for years to come but are expensive. Klad-X is a good adhesive from the manufacturers of Araldite. These adhesives are not to be mixed with mortar and are applied on the prepared surface before fixing the marble.

4.While laying tiles on floors and walls, prepare the base by keeping in mind the thickness of tile. On the prepared base, lay a tile near the door and see that the door opens easily without touching or scratching the tile. Otherwise, choose a thickness that allows easy opening of doors. Nothing can be done afterwards as the door cannot be peeled off later nor can the tiles be changed.

5.Take a long string, dip it in chalk powder and hold it along the diagonals of the room. Pluck the string along each diagonal. It will leave a chalk mark on the floor giving you the centre of the room. Now find the centre point of each wall. Hold the string along the opposite centre points, passing through the middle point and pluck the string. Before beginning to fix the tiles from the centre line outwards, check the space that gets left near the opposite walls. If a slight left or right shift of the centre line saves cutting of tiles, do so.

6.Use ½ to ¾-inch-thick 1:3 cement sand mortar for laying tiles on floors. Prepare cement slurry to lay over the mortar bed and fix tiles in it. Wet the reverse side of the tiles before laying. There is no need to immerse them in water. Joints in tiles are 1.5 to 2 mm wide. Tap the tiles well with a wooden tack hammer from the mason to press them in position. There shouldn't be any hollow sound on tapping a tile that indicates a void below. Some companies like Orient and Sahara provide joint-free tiles. This flooring has hairline joints joined with an invisible grout. These enhance space as the tiles give the feeling of a large slab. The cost, of course, is higher, about Rs 60 per tile of 400×400 mm size.

7.The most important aspect of laying tiles is that their joints should match perfectly. Otherwise, dust will get accumulated. Have a perfectly leveled base. For marble, when cutting and polishing is complete, the joints get matched fully. But in tile flooring, no grinding or polishing is involved. It all depends on the mason's skill. Try to apply the mop on the laid tiles in one swift go. There should be no resistance to it at the joints.

8.If tiles are to be fixed along the curved edge of a washbasin, create a cardboard template of the curve. Now, lay the required number of tiles on the floor or a plain surface, put the template over them and transfer the curve to the back of the tiles. Mark the tiles 1, 2, 3, 4… and cut them along the curve. On fixing these tiles along the curved surface of the washbasin, you will find no difference between the edge of the washbasin and the tiles.

9.To fix a tile around a pipe or trap in the floor, cut the tile into two pieces and remove semicircles from each piece to fit them exactly around the pipe or trap. To fix tiles around a WC, make a cardboard template of the base of the WC, lay a few tiles together and cut them as per the template. Now, fix the tiles around the WC without leaving a gap.

10.If you want to use an adhesive to fix the tiles in flooring, there is no need to soak the tiles in water when an adhesive is used. Note that while laying the flooring for upper floors, no sand is to be laid over the RCC slab. Instead of 4-inch-thick layer of lean concrete (as laid for ground floor), lay a layer of 1½- inch-thick 1:6:12 concrete over the slab and then follow the same procedure as described for the ground floor.

11.For grouting laid tiles, the normal method is to use white cement mixed with pigment matching the shade of tiles. Grout the tiles 24 hours after fixing. Use a grout rather than white cement. Such grouts are available in market in packs of 500 gm, 1 kg and 10 kg. These are polymer-modified cements available in many shades matching the shades of tiles. Rainbow Tile Mate and Bostik Tile Grout are a few good grouts. To apply, take three parts of grout and mix with one part of water by volume to get a smooth paste. Apply to the tile joints by using a squeeze trowel. Use a sponge to wipe off the surplus grout. Allow 24 hours to dry.

12.If a fixed tile gets broken during laying, remove it with a chisel and hammer by breaking it at the centre. Don't touch its edges to avoid damage to surrounding tiles. Remove all adhesive from the base with a chisel, gently hack the sub-base and fit in the new tile. In case some edges get a little broken during transportation or handling, use these tiles at the junction of floor and wall so that broken edges are hidden below the skirting on the wall.

13.For a 1.5 mm to 2 mm joint width, about 300 gm of grout is needed for 1 × 1 ft tiles and 220 gm grout is needed for 2 × 2 ft tiles. Nowadays, 'fix tiles and grout' products are also available in the market and can be used immediately after fixing instead of waiting for 24 hours. Use this grout only if you are in a hurry to finish the flooring work. Another option is to use an epoxy grout. It is waterproof and has excellent fixing properties. It has three components: base, hardener and filler. An 800 gm pack will have 100 gm hardener, 200 gm base and 500 gm filler. However, this grout is better suited for commercial buildings. In residences, use normal polymer-modified cement grout. After the use of grout, don't wet the tiles for at least two weeks.

In the 33rd in a series of clip-and-keep practical construction tips, Engineer Jagvir Goyal discusses aspects of marble and tile flooring. 1.While installing marble flooring, lay it over a ½-inch-thick bed of 1:3 cement mortar. Add polymer adhesive to the mortar for better grip. Use a liquid adhesive; Fevimate is excellent. For correct use, mix 1 kg of the adhesive with 20 litre of water and stir well. Add this solution to dry mix of cement and sand till you get a uniform mortar. Spread this mortar on the base, comb it with a notched trowel and fix marble slabs over it. When adhesive is used, cement mortar used may be 1:5 instead of 1:3. Thus, part of the cost of the adhesive is recovered. See that no air gaps are created below the marble slabs by any unevenness of lean concrete or mortar. Select skirting pieces from end pieces of marble. This will ensure that the skirting and flooring will match and look beautiful. Use long pieces of skirting for minimum joints. 2.While laying flooring in rooms, prefer to maintain dead level of floors. Provide a slope of 1 in 70 in bathrooms, toilets and kitchen towards the floor trap. In verandas, provide a slope of 1 in 70 towards the outside. As marble soaks moisture, always keep the top level of the marble flooring flush with DPC. If it is laid at a higher level, it will soak moisture from the sand below and pass it on to the walls. Don't let anyone walk over the marble for at least seven days. 3.To fix marble on the walls, the same adhesive used for the marble flooring can be used. However, for walls, keep the cement sand mortar at 1:2 ratio. You can also choose an epoxy-based, non-shrinking and non-staining adhesive. Such adhesives provide bonding strength for years to come but are expensive. Klad-X is a good adhesive from the manufacturers of Araldite. These adhesives are not to be mixed with mortar and are applied on the prepared surface before fixing the marble. 4.While laying tiles on floors and walls, prepare the base by keeping in mind the thickness of tile. On the prepared base, lay a tile near the door and see that the door opens easily without touching or scratching the tile. Otherwise, choose a thickness that allows easy opening of doors. Nothing can be done afterwards as the door cannot be peeled off later nor can the tiles be changed. 5.Take a long string, dip it in chalk powder and hold it along the diagonals of the room. Pluck the string along each diagonal. It will leave a chalk mark on the floor giving you the centre of the room. Now find the centre point of each wall. Hold the string along the opposite centre points, passing through the middle point and pluck the string. Before beginning to fix the tiles from the centre line outwards, check the space that gets left near the opposite walls. If a slight left or right shift of the centre line saves cutting of tiles, do so. 6.Use ½ to ¾-inch-thick 1:3 cement sand mortar for laying tiles on floors. Prepare cement slurry to lay over the mortar bed and fix tiles in it. Wet the reverse side of the tiles before laying. There is no need to immerse them in water. Joints in tiles are 1.5 to 2 mm wide. Tap the tiles well with a wooden tack hammer from the mason to press them in position. There shouldn't be any hollow sound on tapping a tile that indicates a void below. Some companies like Orient and Sahara provide joint-free tiles. This flooring has hairline joints joined with an invisible grout. These enhance space as the tiles give the feeling of a large slab. The cost, of course, is higher, about Rs 60 per tile of 400×400 mm size. 7.The most important aspect of laying tiles is that their joints should match perfectly. Otherwise, dust will get accumulated. Have a perfectly leveled base. For marble, when cutting and polishing is complete, the joints get matched fully. But in tile flooring, no grinding or polishing is involved. It all depends on the mason's skill. Try to apply the mop on the laid tiles in one swift go. There should be no resistance to it at the joints. 8.If tiles are to be fixed along the curved edge of a washbasin, create a cardboard template of the curve. Now, lay the required number of tiles on the floor or a plain surface, put the template over them and transfer the curve to the back of the tiles. Mark the tiles 1, 2, 3, 4… and cut them along the curve. On fixing these tiles along the curved surface of the washbasin, you will find no difference between the edge of the washbasin and the tiles. 9.To fix a tile around a pipe or trap in the floor, cut the tile into two pieces and remove semicircles from each piece to fit them exactly around the pipe or trap. To fix tiles around a WC, make a cardboard template of the base of the WC, lay a few tiles together and cut them as per the template. Now, fix the tiles around the WC without leaving a gap. 10.If you want to use an adhesive to fix the tiles in flooring, there is no need to soak the tiles in water when an adhesive is used. Note that while laying the flooring for upper floors, no sand is to be laid over the RCC slab. Instead of 4-inch-thick layer of lean concrete (as laid for ground floor), lay a layer of 1½- inch-thick 1:6:12 concrete over the slab and then follow the same procedure as described for the ground floor. 11.For grouting laid tiles, the normal method is to use white cement mixed with pigment matching the shade of tiles. Grout the tiles 24 hours after fixing. Use a grout rather than white cement. Such grouts are available in market in packs of 500 gm, 1 kg and 10 kg. These are polymer-modified cements available in many shades matching the shades of tiles. Rainbow Tile Mate and Bostik Tile Grout are a few good grouts. To apply, take three parts of grout and mix with one part of water by volume to get a smooth paste. Apply to the tile joints by using a squeeze trowel. Use a sponge to wipe off the surplus grout. Allow 24 hours to dry. 12.If a fixed tile gets broken during laying, remove it with a chisel and hammer by breaking it at the centre. Don't touch its edges to avoid damage to surrounding tiles. Remove all adhesive from the base with a chisel, gently hack the sub-base and fit in the new tile. In case some edges get a little broken during transportation or handling, use these tiles at the junction of floor and wall so that broken edges are hidden below the skirting on the wall. 13.For a 1.5 mm to 2 mm joint width, about 300 gm of grout is needed for 1 × 1 ft tiles and 220 gm grout is needed for 2 × 2 ft tiles. Nowadays, 'fix tiles and grout' products are also available in the market and can be used immediately after fixing instead of waiting for 24 hours. Use this grout only if you are in a hurry to finish the flooring work. Another option is to use an epoxy grout. It is waterproof and has excellent fixing properties. It has three components: base, hardener and filler. An 800 gm pack will have 100 gm hardener, 200 gm base and 500 gm filler. However, this grout is better suited for commercial buildings. In residences, use normal polymer-modified cement grout. After the use of grout, don't wet the tiles for at least two weeks.