Planning new floors and tile

A good floor starts with the floor under it. Flooring and tile show every bump and soft spot in the subfloor, and the cost of fixing it afterwards is high. The quantity side is simple (area plus waste, in boxes), but the order of work matters: prepare the subfloor, install the floor, then the trim and thresholds.

This planner works for laminate, vinyl plank, hardwood, tile and carpet. The preparation is different for each, so check the maker's instructions.

Step 1: Measure the room and add waste

Measure each room as a rectangle and add up the pieces. Flooring is sold in boxes of a stated coverage; tile in boxes or by the piece. Allow 5 to 10% for cuts on a straight lay, and 15% for diagonals or patterns, and a few percent more if you want spares for later repairs.

Step 2: Prepare the subfloor

The floor must be flat, clean, dry and firm. Fix squeaks and loose boards, grind or fill high and low spots, and test concrete for moisture. A second layer of plywood is sometimes used as an underlayment, and tile over a wood floor needs a stiff, flat base with a backer board or an uncoupling membrane.

Step 3: Order the flooring and the underlay

For a floating floor, the order is the boxes of planks, the underlay roll, the trim and the thresholds. Let the boxes sit in the room for a couple of days to acclimate. Carpet is sold by the square yard or in rolls of a stated width, and seams matter.

Step 4: Tile, mortar and grout

Tile quantities depend on the tile size and the grout joint. Thinset mortar is sold by the bag at a stated coverage, which depends on the trowel notch, and grout by the pound. Large tiles need a very flat floor and a bigger trowel.

Step 5: Heated floors, trim and finish

Electric floor heating mats go under tile or some floating floors and are planned by the watt per square foot. Baseboard and thresholds finish the edges.

Before you start

• The moisture level of a concrete slab, and the manufacturer's subfloor requirements.
• The acclimation time for the flooring in the room.
• The transitions to other floors and the height of the new floor at the doors.
• Spare boxes from the same batch.
• Dust and noise: plan where the cutting will happen.

Mistakes that cost people money

• Laying the floor over an uneven or damp subfloor.
• Ordering only the measured area without waste.
• Not letting the flooring acclimate.
• No expansion gap at the walls for a floating floor.
• Tile on a subfloor that flexes, which cracks the tile and grout.

Frequently asked questions