Methods for laying quarry tiles and ceramic floor tiles

If you intend to glue tiles to an existing floor, the existing surface needs to be strong and stable before you start. Any existing weaknesses in the floor need to be remedied before you begin.

When I am glueing floor tiles I use the big sacks of floor glue, that simply need mixing with water before they are used, but on the occasions where I have needed to tile straight on top of some existing tiles I have used premixed 'ready to use' glue. This is more expensive to buy, but has additives already combined that make it more flexible and more 'sticky'.

It is possible to stick one layer of tiles on top of another, if the existing tiles are solidly attached to the floor below, using this premixed glue. You do need to thoroughly clean the existing floor tiles first, then it is a good idea to 'paint' on a solution of 'resine d'accrochage' (like PVA, this will make the surface less slippery so the glue can adhere better) - available in bricolage shops.

It is also possible to fix tiles onto a wooden subfloor. I have done this in one lounge and not a single tile has moved in five years (these are heavy quarry tiles). But it is important that the wooden floor under the tiles is screwed down very rigidly to the joists. 22mm thick, hydrofuge (green) tongue and groove chipboard works, with lots and lots of screws to hold it down.

To be completely sure that the tiles will hold, I would again recommend using resine d'accrochage and premixed floor glue

It is not always necessary to pour a solid concrete floor before laying tiles on an old earthen floor, but it is crucial to have a clean, dry, well aerated stable floor. The 'traditional' approach to laying tiles, without concrete, is as follows:

• remove the top few inches of earth (without undermining the structure of the property, of course, especially if your property has no foundations)
• place a layer of insulation on the floor
• place a thin flexible strip around the edges of the room, which can subsequently be removed - this is to to leave a ventilation gap after the floor has been laid
• place a 15cm layer of small rocks or hardcore, and ensure it is well compressed (use a compressor machine)
• pour a chape (screed) several centimetres deep on the floor, made of a dryish mix of water and hydraulic lime
• the tiles can then be laid, using more lime mix as an adhesive

I have to admit, I learned this technique from someone, but have never actually used it myself. I would ensure that you can make the chape correctly (try making a small quantity first) before setting to. The same technique would work fine with a normal mortar chape.

If you are using 'conventional' ('simply add water') tile glue (colle de carrelage) both the floor and the tiles should be dampened before you start laying tiles. This will help slow down the drying of the glue.

If you are laying large tiles or heavy quarry tiles you should put a good layer of glue on the floor first, spread evenly witha large-toothed spreader, then also put a layer on the back of the tile. Place the tiles gently on the floor at first, using spacers as required between them (5-8mm is usual depending on the size and evenness of the tiles - quarry tiles can be very irregular shapes and need the larger spacers).

When a few tiles have been put lightly into place push them more firmly into place - I usually use a large spirit level, or a masons bar for doing this, because it ensures a flat regular surface across lots of tiles.

A couple of other general hints for tiling:

• don't force the tiles right up to the wall at the edges of the room. You should use a thin flexible strip between the wall and the edge tiles to allow for slight movement, and to stop damp in the wall from crossing the floor
• don't start tiling unless your floor is completely level, because you'll end up with gaps and tiles that won't fit
• draw a straight line across the floor in the most important sight line - this is usually the line that you see as you enter the room or the one that leads to a window and catches the light. Start tiling with this line and work outwards from here
• don't tile yourself into a corner!
• use your tile spacers. If you don't constantly check the spaces between the tiles you will eventually reach a point where two rows of tiles are growing apart of moving together
• after every row has been laid, stand back and look along the lines between the tiles, from low down. You should be able to see form one end of the room to the other along the 'trench' between two rows of tiles
• don't walk on the tiles until you are completely sure the glue (or lime) is properly dry, this usually takes days not hours.

Jointing between tiles

When you are jointing between quarry tiles you can use the same mix of lime and sand as for pointing a wall (see separate section) except that the sand will need to be finer (I sieve the sand to remove the larger particles, it might be easier just to buy a sack of finer sand.)

It is preferable to give the tiles a coat or two of linseed oil before you start jointing between absorbent quarry tiles. This helps stop the lime from staining the tiles, and any excess on the surface of the tiles can then be wiped off easily.

To protect your new quarry tile floor, and make it look attractive as wel, you will need to add a sealant. One option is to add several more coats of linseed oil.

A better alternative is to use some turpentine (terebenthine), mixed one part turpentine with two parts of linseed oil, and also adding drying agent (siccatif in French, usually ink blue and in a small bottle). A couple of coats brushed on should be enough. The tiles can also be waxed for further protection.

All these products are available at low cost in most bricolage shops. There also exist ready-mixed, but more expensive, products which can be appled by simply wiping them on with a damp cloth, or even mopped on.

Personally I prefer the 'home made' types of protection, in part because the linseed oil adds a yellowish hint which the more expensive products usually carefully remove. I have always found that this yellow hint has an immediate and attractive 'aging' effect on the new quarry tile floor.

Tiling on concrete

Between the concrete floor and the tiles there will be a 6-7 cm layer of mortar, to make the floor surface flat and smooth. If you want to do your own tiling, but are not sure you can lay the screed/chape accurately enough yourself, flooring/tiling companies will be able to do this for you. They can pour a liquid floor on your concrete that is self-levelling and sets completely flat. The concrete subfloor will be placed by a mason.

Other floor tiles

There are a bewildering array of floor tiles available. Many ceramic type tiles are in a convincing stone or quarry tile effect finish, and prices can vary from as little as 5-7 euros per square metre to very expensive. These ceramic tiles are easier to maintain and clean than quarry tiles.

Laying ceramic tiles will follow the same advice as for quarry tiles. It is generally much easier to lay ceramic tiles than quarry tiles, because the tiles will be exactly square, not so thick (typically 8 mm instead of 20mm), and of a regular thickness.

The main difference is in the pointing of the joints, which will usually use a pre-made (shop bought) jointing mix (just add water) rather than a home made mixture. The joints between floor tiles are usually 4 - 5 mm, sometimes even less - more narrow than is usually possible with quarry tiles.

The ceramic tile floor will not need sealing after it has been laid, since the tiles are already finished with a non-absorbent surface.

Tiles that are to be used used on the floor in kitchens and bathrooms should not be the highly shiny, smooth tiles, because they will become too dangerous to walk on when they are wet. Many tiles come in 'anti-slip' versions to avoid this.