How to lay interlocking garage floor tiles

Before the first tile goes down

Tiles that have spent a day in a cold van are not the size they will be in your garage. Plastic moves with temperature, and a tile laid cold and then warmed up grows. Open the boxes, spread the tiles out on the floor of the garage they are going into, and leave them long enough to settle to the room. Overnight is not excessive. A floor laid straight off the delivery van is the floor that develops a ridge a week later.

Sweep the slab properly while you wait, and clear the room. Everything comes off the floor, including the freestanding shelving, because you cannot lay a floating floor around a loaded unit and expect it to sit flat. If the slab needs more than a sweep, that is its own job and it happens before this one, not during it. Bring the tools in now as well: a rubber mallet, a chalk line, a tape, a long straightedge and whatever you will cut with, so nothing stops the run once it starts.

Decide which way the tiles face. Most interlocking tiles have loops on two edges and pegs on the other two, and the whole floor wants them the same way round. Pick the orientation before you start, so every tile in the box goes down without turning it over in your hands first. Rigid tiles are usually moulded to show which edge is which; a flexible tile is less obvious, and one laid the wrong way round shows up two rows later as a joint that will not close.

Where to start, and why it is not against the wall

Starting in a corner, tight against two walls, and working outward is what most people try first, and in a garage it is wrong. Garage walls are rarely square to each other and rarely straight along their length. Start a run of tiles hard against a wall that is a few degrees out, and every row inherits that angle. By the time you reach the door, the tiles are visibly crooked against the one edge everyone looks at, and the cuts along the far wall are wedges.

Take the reference from the door opening instead, because it is the edge you see every time you walk in, and because a full row of tiles at the door is the row that gets driven over. Snap a chalk line across the floor parallel to the door opening, a tile or two inside it, and then a second line square to the first down the length of the room. Check the square with a tape: measure three units along one line, four along the other, and the diagonal between those points should be five.

The alternative is to start from the centre of the room and work outward, which gives you equal cuts at both side walls. Which is better depends on what you want to look at. The table sets it out. A garage you park in usually wants the door line, because the row that gets driven over is then a row of whole tiles locked into the field. A garage that has become a workshop, where the door is rarely opened, can afford the centre line and the balanced cuts.

Dry-lay before you lock anything

Lay one full row along the door line and one down the length of the room without connecting them, just resting in place. This tells you three things at once: how the last tile lands against each wall, whether the pier or the door frame falls on a joint or in the middle of a tile, and whether your reference line is where you want it. It takes ten minutes and it is the difference between a floor you planned and one you discovered.

If a dry row leaves a sliver of a few centimetres at a wall, shift the whole line by half a tile so both sides get a sensible cut. A narrow cut tile is fiddly to make, weak once made, and the first thing to lift when a wheel goes over it. Now is the only time moving the line costs nothing.

Laying the field

With the lines fixed, the field is the quick part. Work from the reference lines outward in an L, so every new tile locks into two neighbours rather than one. Tap the joints together with a rubber mallet or the heel of your hand; a tile that will not seat with moderate force has grit in the joint or is the wrong way round, and forcing it splits the loop.

Keep the pattern honest as you go. Every few rows, sight down a joint line from the door end. If it is drifting, you find out while the fix is two rows, not twenty. Drift usually means a piece of grit in a joint, or one tile tapped home before its neighbour was seated, so the cure is to find that tile rather than to lean on the rows after it. A tiled floor is only as straight as its worst joint.

1. 1AcclimatiseUnbox the tiles and leave them spread out in the garage until they are at room temperature. Overnight if the delivery was cold.
2. 2Clear and sweepEverything off the floor, including freestanding units. Sweep the slab. Deal with anything loose or badly uneven before you go any further.
3. 3Mark the reference linesSnap a chalk line parallel to the door opening a tile or two inside it, then a second line square to it down the room. Check the square with the 3-4-5 method.
4. 4Dry-lay two rowsRest a full row along each line without connecting anything. Look at where the last tile lands against each wall and at what falls on a joint.
5. 5Shift the line if the cuts are uglyA sliver at a wall means moving the whole line by half a tile so both sides get a sensible cut.
6. 6Lay outward from the linesWork in an L so each tile locks into two neighbours. Tap joints home; never force one that will not seat.
7. 7Leave the expansion gapStop short of every wall and fixed object by the gap the maker specifies. Do not lay tight to the wall.
8. 8Cut the edge row lastMeasure each edge tile in place, cut it, and fit it. Fit any ramp edges at the door once the field is down.

The expansion gap and the edge row

The gap at the walls is not optional. A tiled floor warms up in summer and each tile grows a fraction; across a whole garage those fractions add up to something you can see. With room at the walls, the floor expands into the gap and nobody notices. Laid tight, it has nowhere to go and lifts into a ridge, usually near the middle, usually in the first hot week. The gap most makers specify is in the region of a centimetre, but use the figure printed for the tile you bought, and leave it at the door frame and around any pier as well as at the walls.

The edge row is cut last because it is the only row whose size you do not know until the field is down. Measure each edge tile in position, allowing for the gap, and cut it with a jigsaw or a fine-toothed handsaw for a rigid tile, or a sharp knife and a straightedge for a flexible one. Cut with the tile face-up on a board and support both sides of the cut, because a rigid tile that flexes as you saw it snaps along the ribs.

Around the door, the pier and anything you cannot move

A pier in the wall, a step, a soil pipe boxed in a corner: each one is a notch out of a tile rather than a straight cut. Make a card template, transfer it to the tile, and cut it slightly generous, remembering the gap. It is far easier to take a little more off than to bin a tile that was cut tight.

At the door, fit the ramp edges last and check the door itself before you call it done. Open it slowly and watch the bottom edge against the new floor height. If it touches, the answer is to stop the tiles a little further inside the opening, not to force the door. Then drive in, get out, and open the car door. The tiled floor has raised the sill by a few millimetres and the car door now meets the wall, the shelving or the bike a fraction lower than it did. It is rarely a problem; it is always worth a look.