I am a owner builder building my workshop. I will be sheathing the roof with 1/2inch OSB with the radiant barrier. Since I am only working on weekends and have poor planning skills related to the rainy weather that will be hitting just as I start placing the OSB, how does the osb react to rain?
Can it take some rain? Should I tarp is if rain is on the way? How about sheets of plastic? Or wait til spring?
Any thoughts will be appreciated.
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Replies
The OSB will get trashed.
Go with plywood.
Tarp whatever you decide to use....but don't wait till spring.
J. D. Reynolds
Home Improvements
There must be a lot of difference in OSB because where I live in CA the OSB would withstand a lot of water but here in IA it is junk. Here in IA it is also a lot lighter in weight and also lighter in color.
Seems I recall an old thread here saying something to the effect of certain osb mills in certain parts of the country use different species of pulp from one another in the manufacture of the sheets.
Perhaps that might have a say in various results of longevity in wet environments.
be sounded good to me anyhowwhen in doubt add garlic
There are high grades of OSB that are much different than what is used for housing. I know a gent who makes some very high end office furniture using some of it.
yur right....
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!<!----><!---->
Forget the primal scream, just ROAR!!!
I think you're right, osb in different parts of the country must be made with whatever trees are available.
Beer was created so carpenters wouldn't rule the world.
When I lived in CA the OSB we used would swell very little if left outside in the rain. So I wonder if they used a different glue as well?
species has something to do with whether it will swell and how much.The type of glue and how well it saturates the chips and how correctly it is all pressed effects whether it will fall apart and how soon.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Same here, OSB tends to last better when wet.
I have seen one hard rain delaminate multiple sheets of cdx, and the osb remain unaffected.-----------------------------------------------------------------------------
WWPD
That's what my roofer thinks too, but I still don't want to use it.
I don't want to hijack this thread but I have a related question. In doing tile work everyone is in agreement that particle board is a very bad underlayment and should never be used because it swells when it gets wet. OSB is considered a recommend underlayment. Now it appears that almost everyone agrees that OSB is no good when it gets wet. So is OSB good under tile or not? (I don't mean tile directly on OSB; there should always be CBU, Ditra, etc). Thanks.
So is OSB good under tile or not?
Ben, I would think that all wood underlayments would be a haven for mold if you were allowing signficant amounts of water through.
I can say for certainty (I've seen it) that some plywoods will delaminate and show signficant signs of damage under limited exposure to wet conditions and I can say with certainty that I've observed OSB enduring very significant water exposure and remained intact and usable.
There is no black and white easy answer.
blue
Our Skytrak is for sale. It has 500 hrs on it. We want 50k (you pay the freight) and we'll finance it. Drop me an email; it's a good buy.
Man you guys are all too nice.
I thought one of ya would have commented on the "OBS" in the title <G>When asked why is there four engines on a 747------ "cause we couldn't fit six" a Boeing engineer
rain and OSB don't mix at all...
keep a dumster handy..
plywood or Aventec and plastic..
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
If your worried about it, don't use it, use plwyood.
If it's the money and the osb is in your budget, then buy a big tarp and be done with it, no worries!
Marco, call your lumberyard and ask if they can supply 5/8" Advantech tongue and groove decking for your roof. Everyone says it's the cat's meow for holding up to rain... unforunately I cannot get it here.
An alternative would be to get a few extra hands on the job on a clear day, get the sheeting up, then get felt on top of it the same day. Unless your workshop has a lot of hips, valleys, dormers, and cupolas that should be possible.
David- can your lumberyard get structurewood gold, by GP, I think? That's what I could get over in eastern washington- basically the same as Adventech, OSB made with higher quality, moisture proof glue. Guaranteed not to swell at the edges.
I don't remember how much more expensive it was- I'm thinking the 3/4" t+g was in the $28-30 a sheet range. zak
"When we build, let us think that we build forever. Let it not be for present delight nor for present use alone." --John Ruskin
"so it goes"
I asked the local yard to look into Advantech... they came back with something called Ainsworth Durastrand T&G. IIRC I posted here asking if anyone had seen hide nor hair and got no reply. Probably time to call some Seattle area yards. I can get a unit of 3/4 moved up here for about $200... not free but not prohibitive for a product that's probably a lot better for winter work.
My mistake, it's Weyerhaeuser Structurewood Edge Gold. Catchy name, huh?
Anyway it seems like it should be stocked not too far away from you- Mt vernon, maybe?
Here's the website, scroll down for the gold stuff: http://www.weyerhaeuser.com/ourbusinesses/buildingproducts/structurwood/products/flooring.asp
zak
"When we build, let us think that we build forever. Let it not be for present delight nor for present use alone." --John Ruskin
"so it goes"
David,T&G on a roof?Joe Carola
T&G on a roof?
That struck me as odd also.
J. D. Reynolds
Home Improvements
Where I once lived it was either T&G or clips.
Here its clips with 1/2 or without using 5/8.
I think that's what Piffin said he's using. Or Smith. Not sure...
5/8" hereTher was another thread dealing with this and a couple guys in northern places with heavy snow loads needed to use 3/4" to meet code requirements
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I know of a guy that half azzed framed his addition and used osb. It's been weathering now for more than six years. It's holding up fine. He actually shingled over one section of it that was exposed for more than three years. It looks fine from the road.
blueOur Skytrak is for sale. It has 500 hrs on it. We want 50k (you pay the freight) and we'll finance it. Drop me an email; it's a good buy.
Rain + OSB = Shredded Wheat
@@ Rain + OSB = Shredded Wheat
Not always. We did five homes in Mt. Vernon and the sub floors were OSB.
Had to drill holes to let the rain water into the crawlspace, but other than that, not much of a problem. They have versions that are a lot more rain resistant than others. The ToolBear
"Never met a man who couldn't teach me something." Anon.
In some parts of Wyoming and Idaho osb is almost the siding of choice, second only to tyvek.
Beer was created so carpenters wouldn't rule the world.
Like David said, get a few friends, and try to sheathe the roof and get the felt on in a day or maybe a weekend. Some guys here are using roofing underlayments other than felt- the stuff is tougher, installs faster (wider rolls), and with plasticaps, it won't tear off in the wind. That way, the roofing can wait a little while.
Another method I've used- when you staple down the felt, staple twine along the bottom edges of the felt. It'll help keep the felt from tearing.
zak
"When we build, let us think that we build forever. Let it not be for present delight nor for present use alone." --John Ruskin
"so it goes"
I agree with the rest, don't mix OSB with water. I'm not going to say don't use it, but get it covered pronto. I've been hearing the OSB w/ the foil is a great way to go for roofs in terms of temperature management and OSB being more friendly (just not with water. Get it off the ground, tarp it well, or roof it and get felt on. Many roofers around here you the plastic button cap nails to hold down the felt and prevent water.
Marco101,
I too am an owner builder working nights and weekends.. I used OSB on the roof, well actually I used SIP's which were made with OSB. 4 years later I got to the final little chunk of roofing which has been exposed to winter snow rain and etc. without any protection.
The OSB is still sound and held nails without a problem. Now to be fair SIP's use a high grade OSB with a better than average grade of "glue"
To those who believe that plywood is a better answer, please check which plywood is selected. I've seen plywood delaminate just as quickly as cheap OSB.
I would offer you a suggestion, if you haven't purchased the OSB as yet, Swing by a saw mill and buy their lower grades of solid wood. I can buy Pine, basswood, etc. for only 20 cents a bd.ft. that makes it cheaper than OSB. nailing it up is a whole bunch easier than nailing sheets of OSB or plywood (not nearly so bulky) and if it's green so much the better!
As the wood dries it will form what is called skip sheathing.. That is a good thing! it will allow the bottom side of the shingle to dry and they will live a whole lot longer!
Plus you are nailing into a one inch thick board. It will hold nails a whole lot better than OSB ever will.
Osb will hold up fine. A few days of rain to a few weeks wont hurt it.
Hi Guys,
Thanks for all the imput. I think I will have a work party to get the osb up on a weekend, have the inspectior out the next day, and then get the felt on. I will have some plastic sheeting standing by, and if I do not need it, return it to HD.
By the way, 30 lb felt or 15 lb felt, when would you use each one?
If you're going to use felt then 30 lb. is the one to use.
Some of the new underlayments are also worth a look-Roof Top Guard and Titanium UDL
Here in the Pacific Northwest every house invariably gets wet during construction. I haven't seen too much trouble on roofs, but many builders use osb for subfloors and I have seen quite a few kitchens that had ridges visible in the sheet flooring where the edges of the osb had swelled. These ridges telegraphed right through the underlayment. I wouldn't use it around tile.
Neither. Use a new synthetic underlayment. Waterproof, not slippery, rolls flat, doesn't degrade... and one roll that easily tucks under your arm as you go up the ladder will cover the WHOLE roof... unless your shed is more than 10 squares large. Why even bother with an older crappier product?Rebuilding my home in Cypress, CA
Also a CRX fanatic!