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I know this stuff gets a lot of attention but the first floor framing on our house is complete and has been exposed to steady rain for two days now. The area I’m concerned about is the 3/4″ T&G OSB decking that’s getting saturated. Will I end up with squeaky floors and boards that have buckled or does this stuff return to its normal size and integrity after it dries out? If there are any pros out there who have experience using OSB I would appreciate feedback. I’ve heard positives about OSB in that you don’t get the delamination that occurs with CDX but it will swell.
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It'll swell and it'll shrink. Your concern is good but there's not much that can be easily done about it to my knowledge. Once the house is dried in, and if nobody else does, screw it off and sand the high spots before underlaying or carpet. Best of luck.
*Max,Start worrying after a full week of rain. 2 days shouldn't be a problem. Drill some small drain holes with a battery drill if there is standing water for long periods. Only problem is, if you do drill the holes, you may want to plug 'em later as you may be comprimizing an air barrier otherwise.
*That's why we use fir ply for floors. Worth the extra money for many reasons.OSB, in my opinion, sucks for this usage but last time I said that lots of guys said they think it's fine.Tell us later how it went.MD
*Mad Dog ... tell me more about the fir ply. I am debating using it for floor decks right now -- verses OSB . Its a lot more expensive but I like the quality of it. I wonder about the "softness" of fir. Do you find the fir is not messed up by a few weeks of exposure to weather?I wouldn't use CDX for anything, too many void, and manufacturing errors, such as roll back on the surface layer. I did garage last week and you can see throught the cracks and splits in the CDX. The stuff is never cut square either and it is destroyed by edge nailing and screws. I insist on B/C grade ply as a minimum for wall sheathing.
*Mad Dog ... tell me more about the fir ply. I am debating using it for floor decks right now -- verses OSB . Its a lot more expensive but I like the quality of it. I wonder about the "softness" of fir. Do you find the fir is not messed up by a few weeks of exposure to weather?I wouldn't use CDX for anything, too many voids, and manufacturing errors, such as roll back on the surface layer. I did garage last week and you can see throught the cracks and splits in the CDX. The stuff is never cut square either and it is destroyed by edge nailing and screws. I insist on B/C grade ply as a minimum for wall sheathing.
*Mad Dog ... tell me more about the fir ply. I am debating using it for floor decks right now -- verses OSB . Its a lot more expensive but I like the quality of it. I wonder about the "softness" of fir. Do you find the fir is not messed up by a few weeks of exposure to weather?I wouldn't use CDX for anything, too many voids, and manufacturing errors, such as roll back on the surface layer. I did a garage last week and you can see through the cracks and splits in the CDX. The stuff is never cut square either and it is destroyed by edge nailing and screws. I insist on B/C grade ply as a minimum for wall sheathing.
*Tedd, you can say that again!fyi, you can delete or edit your messages for 30 minutes after posting..Max, I've had OSB get wet for weeks with no problems. Some OSB I've used has slots cut in the tongue to drain standing water.
*I also wouldn't worry about rain on OSB. Just make sure you give enough dryout time after the house is roughed in. Around here, we regularly go through the entire house with a rather, well, large gentlemen and check for squeaks and raised seams. Squeaks get taken out with screws, raised seams through sanding or chiseling before the carpet goes down. However, having said that, I once worked on a Kit house that came with 3/4", 7-ply plywood for the subfloors and 1/2" 5-ply for the roof. It was so sweet (e.g., lack of knots, footballs, and voids), that I could have made boats out of it. Should have stolen it and replaced it with OSB, but that's a different story...
*Well, that's the thing of it. OSB won't disintegrate after a few rains, but it gets so uneven and rough, what kind of subfloor is that? The fir plywood takes a lot of weather. No problems, and when it dries it is FLAT. No goofy seams. No fiddling around later.Has come up a lot in price though in the last year or so. But so has everything it seems.
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Regarding this subject of OSB Subfloors....
I sell Building Materials in Richmond, VA. Many of my customers have come to appreciate a product we stock called Advantech. It is produced by J.M. Huber. Advantech is similar to OSB in looks, however the glues used in its' production are much better than any other OSB, or Plywood for that matter, on the market. It lays flatter than Plywood, which my customers find useful. It also comes with a 50-year Warranty against moisture problems; i.e. sanding due to raised edges. Last year, when the Hurricanes that pounded the East Coast were dumping rain for over a week, I had two jobs that were stopped at the first floor decking stage. Neither of these two houses had any problems. None of these customers had ANY problems with the decks, and they still use the product today. It is priced higher than other OSB Products (TopNotch and others), more in the range of Pine Plywood. The real benefit my customers see is giving their homeowners the 50 Year Warranty. It works. Hope this helps.
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Max...when I built my home I used T&G OSB .It rained like a 'mother' off and on for over a week .I had water standing between the plates for several days.The OSB swelled up in several places but other than that I haven't had any problems.One thing that I do after the decking is on is buy several gallons of the cheapest waterproofing that I can find and apply several coats. This seems to help until I'm dried in.
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About 3 years ago a LP tech rep told me that it wasn't advisable to seal the subfloor as it kept the underneath side of the sheathing from drying and could cause more swelling and or flaking. I haven't really formed an absolute opinion about that yet. My experience with OSB is that once it swelled - it stayed that way. I always rent a floor sander and use it on the entire house's sub-floor. In my area the Advantech is generally a couple of dollars more than the LP Top-Notch .... may try it on the next house.
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I know this stuff gets a lot of attention but the first floor framing on our house is complete and has been exposed to steady rain for two days now. The area I'm concerned about is the 3/4" T&G OSB decking that's getting saturated. Will I end up with squeaky floors and boards that have buckled or does this stuff return to its normal size and integrity after it dries out? If there are any pros out there who have experience using OSB I would appreciate feedback. I've heard positives about OSB in that you don't get the delamination that occurs with CDX but it will swell.