You’ve bought just the right amount of fine, dry, perfect, straight tongue and groove flooring, and you’re ready to start nailing it in. Wait just a minute. Is the room square? Many an amateur floorer has discovered too late that the distance between two opposite walls varies from one end of the room to the other. Blithely nailing the first board parallel to the one wall, they proceed on their merry ways, until they reach the other side and realize that everyone walking into the room is going to see the 1″ difference; the flooring will appear to cut diagonally away from the wall.
So what do you do? If the boards were simple deckboards with a space between them, it would be easy. You could adjust the space between the boards gradually, over the course of the deck. But tongue and groove flooring fits tightly together.
So you have to split the difference on each side. If there’s an inch difference at one end of the room, split this. Let’s say you were already going to leave 1/2″ gap between the wall and the floorboards to allow for expansion. At the wide end of the room make that 1″, and start nailing. You’ll get the same spacing on the other wall. With this method, the floorboards aren’t perfectly parallel to the wall on either side of the room, but they’ll look better.
Remember that a gap between floorboards and wall is allowed. It is in fact, recommended because the boards may expand. Your baseboard, and if necessary, quarter-round will cover this. If you’re using very thin baseboard, though, you’ll need to rip a board on either side to fit more closely to the wall.