Preparing the surface
Thorough preparation of the fixing surface is essential for good results. Make sure it is clean, dry and level so the tiles lie perfectly flat.
If your fixing surface is slightly uneven, first cover it with plywood or tempered hardboard, smooth side up. You can use hardboard nails if fixing to a timber floor, but with concrete you will have to drill holes, insert suitable plugs and fix the hardboard into position with countersunk screws, making sure the screw heads lie flush with or slightly below the surface.
If the fixing surface is very uneven, cover it with 12 or l8mm chipboard or plywood screwed into position. Use flooring grade chipboard when fixing to timber, and resin-bonded plywood for concrete. On an old, worn, uneven concrete floor you may need to use a levelling compound. When mixed with water the compound finds its own level and provides a smooth, even surface.
Laying the tiles
Start laying tiles from the centre of the room, which can be located by stretching two lengths of string (preferably chalked) from the mid-point of each pair of opposite walls across the floor so they cross at the centre. Make sure the pieces of string cross at right-angles and secure the ends with nails or pins. Position two rows of dry tiles, working from the mid-point to the skirting boards .
This will give you the width of the tiles around the perimeter. If only a very narrow strip is left, the floor will have an unbalanced look, especially if you are using vinyl tiles in a dual colour or chess board design. To prevent this, adjust the string line half a tile width off centre to leave wider perimeter tiles. If using chalked string, pluck it and the chalk will leave an accurate impression on the floor. Alternatively, use a straight-edge and a pencil to trace the string lines accurately.
Complete each section of the room with as many full tiles as possible, leaving all cutting jobs until later. If using tiles that are not self-adhesive, spread a thin layer of adhesive on the floor (not on the back of the tile) about a square metre (or square yard) at a time. Don’t spread more than this because the adhesive sets quickly and the tiles must be laid while it is still tacky. Start laying the tiles, pressing each one firmly into position from the centre of the tile outwards to prevent air being trapped underneath.