I just got the roof over our addition. The subfloor which is 3/4in plywood was exposed to about a 5 days of rain. The subflor was swept and blown often, but now that it is drying out I can see several areas where the seams are buckled (no gap between the seam when installed) and some areas where the plywood was so wet the floor has a slight sag to it.

What do I do? Does the plywood eventually dry out and return back to flat? I hate to sound like one of those guys, but for the amount of money i'm paying having a wavy floor is not acceptable.

Also, the floor was insulated before the rain and that is also wet, not soaking but a bit wet. Should I replace this or be worried about water from the insulation evaporating into the bottom of the plywood?

All i got was from the framers and contractor was thats you happens when you build in the winter.. no solution from them.

 

If they had properly used Advantech or another specific subflooring materials rather than plywood, you wouldn't have a problem with the water. Advantech and Home Advantage (orange big box) are wax impregnated so water doesn't soak in. If kept swept off or drained it won't buckle on you. I suspect they were using CDX for subflooring, not sure.

 

good info on Advantech..but I've got plywood glued and screwed down and need to know if it will go back to normal once dry, is there another remedy or do I demand it be torn out and redone.

 

Nope, once deflected, it will probably stay that way, sorry. If you are to a point where it can be removed and replaced by a proper subflooring, do it. Otherwise, you can sand it down prior to installation of flooring material. I would have the contractor ensure one or the other is done to provide you with a flat surface for your flooring. Wavy plywood is not acceptable; bulged seams and delamination is not acceptable. He knows it. Proper use of proper materials is mandatory. Sorry, just fell off my soapbox.

 

Well, your framer and contractor are right about the weather, you can't control it. Is the floor actually dipping in between the joists or does it appear to be because the seams have swelled? As Chandler said, sand the seams with a belt sander and 40-60 grit. For the carpetted areas you probably won't notice unless it is more than an 1/8th. Tiled areas you will have an underlayment that you can level by using(just a thought) some const adhesive in the low areas before the underlayment goes in. There may be another leveling material you can use.

Another thing you can do is once the seams are sanded, put down some 1/2" plywood or osb over the entire floor to clean it up. Make sure to stagger all joints and seams and you will need to use a lot of const adh to adhere the two together and help eliminate squeaks. Good luck.

 

Ask the framer and contractor if they ever heard of tarps. I'm a framer and frame additions in the winter and you can't control the weather, but there isn't one addition that can't be tarped properly so this doesn't happen.

 

It sounds like you are pretty much past the point of pulling the plywood and replacing it. You might just go ahead and get it dry and see what happens. Worst case you could overlay it. Obviously it won't be perfection but will it be ok -- if they used exterior graded stuff -- probably.

 

Joe C
I kinda wondered about that as well. Doesn't help now of course.

Hey, you related to Adam C? He was a carpenter before he got rich on the radio and TV.
lol

 

It doesn't help now, but the GC and Framer are responsible for fixing this problem, not the Homeowner. Don't know why the HO has to fix this.

No relation. He spells his last name different. I think I should go to radio also