Just tore up my carpet in the master bedroom that I am going to hardwood. Subfloor is nice and flat (yey!), but I noticed on some edges (not the short ends but the long ends) they did not provide any room for expansion gaps (the plywood is just butted together).

The subfloor is 6-ply 11/16th plywood (yes 11/16th I measured it like five times-it is bigger then 5/8th and smaller then 3/4th) that appears to be tongue and grooved. There is no curling on the edges of where the plywood has been butted together. Considering the plywood has been this way for 10+ years and has had no averse reactions, can I just leave it like this and hardwood over? Or should I rip it out and open up an expansion gap (that seems like a lot of work!).

Nick

Sounds like the minimum requirement needed, for a subfloor. No you don't need to rip anything out. It is fine like it is.

Just be sure to run the flooring across the joist, and not the same way as the joists.

Thanks floorguy. So the expansion gaps that I always read about needing between plywood panels (I think it is 1/8th of an inch) is not going to be a problem if there aren't any in some spots? Like I said its been that way for 10+ years and there is no curling on the edges or problems.

You are fine Allgo.

The 1/8" expansion is used when installing square edge underlayments over top an existing subfloor.

What I hear you saying is that if your subfloor is not thick enough and you have to add a layer... if you use TIG, no need for gaps; if you use non-TIG, you need to leave gaps.

Bob, if you were to use a T&G plywood for an underlayment you would still need to leave the expansion.

All i'm going to say is leave that subfloor open a week atleast see what it does, if nothing its fine. The wood that going over the top, and with the measurement your saying let that stuff aclimate in the house atleast two weeks if not longer, then install it, sandd out the difference, and let it be what it is.

What you have and what you will have when your done, it'll work. your on the right track.