Industry Best Practices in Building Finishes
Floor trap installation in Toilets
This is one of the most common issue causing the stagnation of water in Toilets ultimately making it slippery and also smelly. As per National Building Code published by Bureau of Indian Standards (BIS), recommended floor slope in Toilets is 1 in 60 i.e. a drop in level of floor by one unit for every 60 units of horizontal. This is necessary for bath water to flow smoothly, without stagnating, towards Floor trap and finally into the drain pipe. The floor should slope towards Floor trap from all directions. Ideally the floor trap should be located at extreme corner abutting the wall. When the Floor trap is not positioned in the extreme corner, the water gets stagnated in the corner causing ponding. Also floor tile should be cut precisely as per the shape of floor trap otherwise the grout filling the excess gap will not only look unsightly but also impedes the smooth flow of water. If for any reason the Floor trap is positioned little away from corner, the corner floor tile has to be cut diagonally and the far edges from the Floor trap have to be made to slope towards Floor trap in reverse direction to avoid water ponding in the corner of toilet.
Floor Tile laying (with spacers).
It is common practice to lay the floor Tiles without gap in joint between the adjacent Tiles. This is also colloquially termed as Paper joint, probably meaning that joint gap is as thin as paper. The logic is that it looks good without gaps and also will not accumulate the dirt.
Though it looks neat, unfortunately this has adverse effects like:
- The thin joint will not allow sufficient grout material into the joint to bond the adjacent tiles resulting in improper bonding between Tiles as well as hollowness below the tiles at the edges.
- The imperfection in laying the adjacent tiles at the same level cannot be managed and level difference gets highlighted resulting in unsightly undulations (also termed as Lippage), which will be felt while walking bare foot and even may cause injury as these edges are sharp especially in Vitrified Tiles. Ideally the lippage (level difference) between adjacent tiles should be less than 0.5 mm when checked with a straight edge.
- Floor tiles while manufacturing, will inherently have warping (curvature of surface in both directions) due to the heat process they undergo. Though Tiles with warping beyond limits are rejected, the Tiles with permissible warping, when laid side by side will have slight level difference. This also shows up when Tile laying is done without joint gap.
- Also any irregularity in cutting of Tile sides during manufacture will make it difficult to lay without joint gap.
As time tested best practice, solution for all above is to lay the Tiles with uniform gap between them all-round by using spacers. Spacer is a plastic component as a pin or in the shape of “ +” and is placed at the corner of Tile so it facilitates uniform joint gap between Tiles. The process will be to lay the Tiles on prepared mortar bed with the required level and slope (in case of Toilet floors) and use spacers to create the gaps which will be filled after the mortar bed hardens may be 2 days later. The joint width can vary between 3mm and 5 mm depends on tile size but less than the Tile thickness and not less than 3 mm in any case as grout cannot enter the gap otherwise.
There are primarily two types of grouts, one is cementitious (Cement based) used for dry areas and other is Epoxy resin based preferred for wet areas to avoid seepage of water. The grouts have to be mixed with colour pigments to match the colour shade of the Tiles or could be in contrast colour to achieve striking pattern. Joints should be cleaned for dust and loose particles before applying grout and footfall on floor should be allowed only after grout hardens as specified by the gout manufacturer. A well jointed Tiled floor not only looks neat but also prevents water seepage and dirt accumulation at joints making it easy to maintain.