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Wet OSB a problem?

31K views 41 replies 24 participants last post by  Duner  
#1 ·
Should I be concerned about an inch of rainwater sitting on my subfloor for 2 days? Most of it dried out quickly, but I have several sheets that have swelled edges and very are soft in spots (I can push a nail through by hand with little effort). Pictures attached. Thanks in advance for the help.
 

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#10 ·
I've been in several homes where I've seen they had to do just that when I went in to remodel, not just OSB but plywood too. Last time I saw it the sub floors were also covered with dirt from being muddy.

If it drys out and just has swelled edges you can grind it, personally I'd replace it.
 
#15 ·
pinwheel said:
You're gonna replace the entire deck of a new house because it got rained on?
It's easer to do it now than when the place is finished and furnished.

I would replace anything that's bad. In this case, likely the entire deck.

One clue it's junk ( you can push a nail through it by hand). LOL....

Or leave it. Tile it, whatever.

He asked for advise, I gave.

Peace.
 
#16 ·
If you can really push a nail through with your bare hands, you have a larger issue. I've been on my current house for almost two months with a wetter than normal summer and the floor is still solid as a rock. Like someone else mentioned, a properly installed floor should drain relatively fast on its own
 
#17 ·
Most if not All sheathing for framing is designed and engineered for getting wet . Usually for a few months. We drill holes to allow drainage and I have never seen damage after a weekend off rain.

If you can push a nail through by hand, you have two choices.

Replace the sheathing cause it's junk.
or
JOIN the circus as the strongest main on earth.

I'd replace the damaged areas if It was my job,
after letting it dry out and re checking my thumb strength
 
#19 ·
Personally, just looking at the couple of damaged pics, I'd replace it and or grind it and relay new on top... will save you all sorts of headaches later...

Bit for future reference, they do make this stuff called plastic that does a good job of keeping rain out... :whistling
 
#20 ·
I had that happen framing some condos a while back, had about an inch of water everywhere. All you can do is take the claw of your hammer and start poking holes in the floor. Make sure the building is dried out and moisture tested before adding any finished flooring. Patching the holes could be an issue but its worth it to get the floor to drain in my opinion, minimize the swelling.

I don't get the people saying if you frame the floor properly it will drain, makes no sense. I framed about a thousand buildings, every one of them puddled water on the floor to a certain extent. Do you guys frame your houses crooked and slope the floor so it drains?
 
#21 ·
KennMacMoragh said:
I had that happen framing some condos a while back, had about an inch of water everywhere. All you can do is take the claw of your hammer and start poking holes in the floor. Make sure the building is dried out and moisture tested before adding any finished flooring. Patching the holes could be an issue but its worth it to get the floor to drain in my opinion, minimize the swelling. I don't get the people saying if you frame the floor properly it will drain, makes no sense. I framed about a thousand buildings, every one of them puddled water on the floor to a certain extent. Do you guys frame your houses crooked and slope the floor so it drains?
I just drill holes everywhere to let the water into the basement.
 
#22 ·
We don't use osb for anything anymore. More for subdivision housing where quality is not the top priority. Some of the houses we build take four or five months to frame and the floor gets wet many times. Drilling holes is the way to go. As stated, there is no way osb would get soft in a few days unless it was already half rotten.
 
#23 ·
KennMacMoragh said:
I don't get the people saying if you frame the floor properly it will drain, makes no sense. I framed about a thousand buildings, every one of them puddled water on the floor to a certain extent. Do you guys frame your houses crooked and slope the floor so it drains?
All 3/4 t&g osb flooring we use has notches in the tongue that form weep holes when installed. If you beat the piss out of the sheets with a sledge hammer, you close up the holes and stop the draining. Granted this is all theory and we all know the real world doesn't always work out that way. Regardless of holes or not, water should not be sitting on the cap like his pics show for two days.
 
#24 ·
SAcarpenter said:
All 3/4 t&g osb flooring we use has notches in the tongue that form weep holes when installed. If you beat the piss out of the sheets with a sledge hammer, you close up the holes and stop the draining. Granted this is all theory and we all know the real world doesn't always work out that way. Regardless of holes or not, water should not be sitting on the cap like his pics show for two days.
Oh, guess I haven't seen that, but good idea.
 
#25 ·
around here plywood is for floors, osb for sheething. Anything else is a code violation because well, osb doesn't do well with standing water and people end up falling through. But different codes for different locations I guess.

But yeah, if you can push a nail through by hand... that doesn't sound like just 2 days of rain. Now chip board, remember chip board? They still sell chip board over there?
 
#27 ·
jferrie said:
around here plywood is for floors, osb for sheething. Anything else is a code violation because well, osb doesn't do well with standing water and people end up falling through. But different codes for different locations I guess. But yeah, if you can push a nail through by hand... that doesn't sound like just 2 days of rain. Now chip board, remember chip board? They still sell chip board over there?
That's pretty ignorant seeing plywood is garbage and there are some osb products that are far superior to any plywood