Laying Quarry Tiles on a Concrete Floor
Calculate the number of tiles needed and plan the layout so that you do not finish with very narrow tiles along any wall.
If you are using hand-made tiles, soak them in water for several hours before you begin work. Clean any cement droppings, grease or oil off the concrete floor.
Cut two gauge rods from planed timber. Make them the same length as a row of six tiles with 3 mm (1/8 in) joints between them. Mark the joint positions on the rods.
Lay the gauge rods out from the straight wall at 90° and lay a batten against their ends, parallel to the wall. Nail it to the floor, remove the gauge rods and place a second batten against the wall. Use battens that are twice as thick as the tiles.
Use a spirit level to check that the battens are level. Use small pieces of wood as packing to level the battens, prising up the nailed batten slightly where necessary.
Next cut a dragging board, the same length as the gauge rods, from a wide piece of timber with straight, parallel edges. At each corner on one edge, cut a notch 3 mm (1/8 in) shallower than the tiles’ thickness, so that the board fits between the battens.
For the bedding, use a 1 : 3 cement-sand mix. Building sand is suitable. The mix should be neither so dry as to be crumbly nor so wet as to allow the tiles to sink.
Spread the mix between the battens with a steel float. Then drag it, with the dragging board between the battens, until you have a smooth, level finish over slightly more than the first area to be tiled.
Lift the batten from the wall and fill the gap with bedding, using a trowel. Dust the bedding with dry cement, to provide a strong key for the tiles.
Lay a row of tiles between the wall and the other batten, using a gauge rod to space them.
Set out the gauge rods from this first row of tiles and place the uncut edge of the dragging board against their ends.
Lift the gauge rods and lay rows of tiles along the batten — again using the gauge rod to space them — then along the dragging board and the wall until all the edges of the area are covered. Then fill the centre.
If, at this stage, the bedding has hardened so that the tiles do not move when touched, brush water into the joints.
Next, beat the tiles down to the level of the battens, tapping them with the face of a block of 100 x 50 mm timber.
Straighten the tiles by running the trowel along the joints. Wash the tiles clean with a sponge and water.
Set the wall batten in place again and lay the next area of bedding between the battens, first dusting the edge of the first area with dry cement.
When one strip is tiled, remove the fixed batten and set out the battens for the second strip, working from the edge of the first strip. Dust the edge of the bedding with dry cement before laying each area of the second strip.
When the whole floor is tiled, strip by strip, leave the bedding to harden for 24 hours before grouting the tiles.
When you have to stand on the floor while grouting, cover the tiles with a large piece of— about 900 x 600 mm (3 x 2 ft) — to prevent them moving.
Use a pure cement mix for grouting. Rub the grout between the tiles with a squeegee.
Remove as much surplus grout as possible with the squeegee. Then rub astick with a rounded end along the joints.
Work over the tiles with a pad of cloth to clean them and absorb any bits of cement. Rub diagonally across the joints at first, then along them.
Wash down the tiles with a soapless detergent and give them a final rub-over with a clean cloth.
If the tiles are outdoors do not polish them. Finish indoor tiles with proprietary tile polish.
Replacing broken tiles
Remove a broken quarry tile from the floor by breaking it up with a hammer and small cold chisel, starting at its centre to avoid damage to adjacent tiles. If adjacent tiles are not firmly bedded, lift them out.
Chisel any projections off the bedding and set the new tiles in position — dry, to check that they do not project above floor level. New tiles must be identical in size and thickness to existing tiles.
If only two or three tiles are to be replaced, bed the new ones with Bal-Tad or similar. If many tiles are to be re-laid, hack up the bedding and re-lay as for a new floor.