Solid

Jerry, Floorguy, Ken,
How about we call the required expansion gapping at perimeter walls and Fixed objects "movement accommodation" rather than expansion gapping?

Do buildings and sub-floors shrink/swell with changes in weather?

New Construcion concrete sub-floors: Does concrete shrink because of continued drying and hydration for a few years?

If the theory is that buildings never shrink and swell and concrete never changes either, than the need for movement accommodation is not needed.

but: Why does Ceramic Tile require movement joints and movement accomodations?
Why do stone installations require movement accommodations and jointing?
I'm sure stone and ceramic have less shrink and swell than wood..

Expansion space (movement accommodation) is not all about the material....

Apples and oranges, Ceramic cannot tolerate any movement, the characterisitic of wood is movement in the widths of the boards. I don't see butting to a metal exterior threshold a big concern.

Then explain the difference in a fixed object and a direction change in a wood floor??

C

Floorguy,
Install your floors anyway you wish.
If an isolated manufacturer wants to make "No expansion" required........... that is a selling/marketing issue with reality completely different.

You quote NWFA standards upon inspecting.. What do the standards require?
Rules are Rules. It is cheaper to follow them.

Okay you guys can discuss elsewhere. This subject has been beaten to death. Locked