How to leave an expansion gap

A reader asked me how to leave an expansion gap when installing laminate floor or any other type of floating fllor. That’s an important question. With the right tools it’s really easy. Without the right tools, it’s incredibly frustrating.

The trick to leaving an expansion gap is to place some type of spacer of uniform thickness between your flooring and the wall on all four sides of the room. You can either use commercially produced spacers or make some yourself from thin plywood or other scrap wood.

Commercial spacers for leaving an expansion gap

how to leave an expansion gap
It’s important to leave an expansion gap when installing laminate flooring to prevent buckling. To do this, use spacers along the walls of the room, which you can either buy or make.

Home improvement stores sell laminate spacers, usually in the same aisle as the laminate flooring. Harbor Freight sells a nice bundle that includes spacers, a pull bar, and tapping block, for less than many stores charge for just one of the tools.

Commercial spacers work for any type of floating floor, not just laminate. They’re usually made of plastic and they’re rectangular, about an inch wide and two inches long. For leaving a thick gap, you can stack two of the spacers together.

To use them, place the spacer in between the wall and the floor to hold a consistent gap.

The problem I have with using small commercial spacers is I tend to run out of them on the sides of the room where the short ends go up against the wall. I may only need 3-4 spacers on the sides of the room that run parallel to the long lengths of the floor. But on the short lengths, I may need 10 or more.

For this reason, professionals sometimes find it more convenient to just make their own spacers, if they have the tools to do it.

Making your own spacers

You can make your own spacers from thin plywood, or even from offcuts of 2x4s or other scrap lumber, as long as you have a way to cut them straight and a uniform thickness. A table saw is ideal for this. Just cut lengths of board a quarter inch thick, at least an inch tall, and however long you like. If you need a thicker gap, just cut the board thicker if you’re using offcuts, or use thicker plywood.

Four-foot lengths are nice because you can use two spacers on each side of the room and cover a lot of ground with them. Just place them them in the gap between the wall and the floor, and slide them over a bit when you need them.

If you have a table saw already and have offcuts to use, making your own spacers is essentially free except for your time.

If you don’t have a table saw, you can make them by sandwiching craft sticks together and securing them with glue or tape.

Finishing up

When you’re done installing the floor and you’re ready to install your baseboards or quarter round, pull out the spacers, then install the quarter round or baseboards to hold the floor down. That’s all there is to it.

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