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Wood flooring, expansion in boarders

The installation instructions for most 3/4" solid nail down flooring states you need 3/4" expansion at the walls. If that is the case how can any boarder be installed without opening up to perhaps 3/4"? Can any corner be mitered? Can you change direction in the flooring without a 3/4" gap". If you go around an island in a kitchen do you need 3/4" on both sides when the flooring is tight all the way around?
We installed a nail down floor that cupped. We didn't leave 3/4" for expansion, there is still room to expand and they say the cupping is due to not enough gap at the walls! Am I nuts or is the manufactures just covering their butts so they don't have to stand behind their product?

A. Spruce
Re: Wood flooring, expansion in boarders

The size of the expansion gap will be relative to the size of the wood flooring area. A large room, say, 16x16 is going to have far more expansion and contraction than a room, say, 5x5. You will have more movement over a raised foundation than you will on slab, because an elevated floor will fluctuate in temp and humidity more than a slab will.

Going around an island, as in your example, the gap will be commensurate with the space between the island and the next solid object. I would not leave more than maybe 3/8" - 1/2" for a walkway of 4'or 5' wide and up to the suggested 3/4" on the dining room side where there is a larger expanse of material to move around.

Re: Wood flooring, expansion in boarders

Cupping is caused by uneven moister on one side as compared to the other not by lack of expansion space. Buckling is caused by the lack of expansion room.


Re: Wood flooring, expansion in boarders

Just to add to the good answers above:

We don't know how you installed your floor, on what kind of surface and if you used a moisture barrier or not, to be able to tell you what went wrong, so more info is needed.

Even if you followed the mfg's guidelines, and left a 3/4" gap all around, there is a way to install baseboards: a regular/standard baseboard (3/8") plus a quarter round (1/2") will cover the 3/4" gap.

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