I am about to build my first house and have a question on sheathing fr the outer walls. What is recommended for two story construction with 2X4’s to be covered by brick in some areas and Hardiplank siding in others. Plywood? Foam, Gypsum? I have the same question for roofing and sub flooring under hardwood?
Thanks
Replies
Pat, you'll probably get a lot more advice over at the Breaktime forum - that's the Fine Homebuilding forum.
>>>>> http://forums.taunton.com/tp-breaktime/
I would say not foam. The sheathing serves an important structural purpose by preventing racking of the structure. Neither foam nor let-in steel bracing are effective. Either plywood or OSB can be used for all the situations you mention. Plywood is more resistant to getting rained on than OSB. Specialty OSB (like Avantec) (I don't think I spelled that correctly), is more resistant than plywood. If you are going to dry it in before it gets rained on then either is fine so long as you use the right grade and fasten it properly.
If you are going to lay ceramic tile, then don't use OSB under it.
The current issue of Fine Homebuilding has an article on just that topic.
You don't say what climate you are in, but 2 x 4 walls don't allow for much insulation. Is there some reason why you are not going with the standard 2 x 6?
Thanks for your help. I am in Maryland and both builders I have talked to said 2X4 with r-13 is sufficient for the area and the cost for 2x6 is substantially more.
The upfront cost is more, but if it gets cold at all, you'll use a lot less energy heating it. It'll also be quieter.
"I cut this piece four times and it's still too short."
Your climate is mild there, so 2 x 4 construction may be ok, but you have cooling costs to contend with there, too, which are not significant up North.
But, people spend thousands of dollars on the stupidest of things in a house, and better insulation actually has a payback in comfort and dollars. If you are interested, ask the builder what "substantially more" means. It might not be so much.
Thanks, that's a good idea. Do people ever do the first floor with 2X6's and the second with 2X4"s?
I've never heard of that. I suppose you could do the first floor with 2 x 6's on 16 inch centers, and the second floor on 24 inch centers, but it would be weird.
Hello I'm in OH and 2by4 walls are standard. Although any wall over 10ft has to be 2by6. I was just wondering where 2by6 was standard?
Probably anywhere it's cold. In upstate New York all the custom homes I've seen are 2 x 6. Spec homes are often 2 x 4.
The reason is insulation. With standard fiberglass you get R-11 with 2 x 4 and R-19 with 2 x 6 which reduces heating costs (and increases comfort) considerably. With upgraded fiberglass you can get R-21 in 2 x 6.
FG batts are the worst insulation available. Standard are R13 and compressed specialized is rated R15. The wood in the woall system adds R1 or so for a potential R16 asembly.But convection currents in a batt insulated wall will lower the effective insulation value when the temps are copld or th ewind is blowing. A 30 MPH wind on a zero degree day reduce the effectiveness to prcaticaly nothing.Blown denspac cellulose, choppedFG BIBsor foam sprayed ion place all eleiminate theis problem and increase the effectiveness of the assembly in a 2x4 wall.I would never use OSB for sheathing. I use Advantec 3/4" for floor decking. Ply is OK but sometimes delaminates. Whoever said that OSB and staples is sufficient must live in a place wher the minimum is acceptable. Many places no longer allow staples for attachment, and OSB is rejected by quality builders out of hand. It can telegraph the edge swelling from any mositure it contacts. It is not nice to see the outline of every sheet of 4x8 material in tha roof rioght thru the shingles.
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Like I said I'm for OH and everyone I see uses 7/16 OSB for wall and roof sheathing . If you space the OSB properly you souldn't have any trouble. Why are staples no longer accepted ? I've torn osb off walls that has been stapled and nailed , I think the staples hold much better !
Yes plywood does delaminate but it's alot easier to repair then sanding the whole floor like you have to do with osb .
NOTE :The minimum is not accepted with me ! Others I cann't speak for .
So what do you use for wall and roof sheathing ? You didn't state.
I use Advanec mostly, sometimes plywood.Staples do not have the same teraout resistance. In hurricane or other high wind zones it will tear through easier. They are starting to require full round head nails too, noit clipped Dheads. For seismic zones, where the walls are shear walls, the staples do not have shear strength and will fex, so they are done being used in west coast locales too. Same applies to flood zones.OSB and stples is the just barely get by with the minimum kind of work for those williong to save less than half a percent on cost. For a few hundred bucks more, a far better structure results.
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I don't understand because I thought Advanec is a OSB product . It;s made the same way and materail ? Do you know where I can get information on Advanec ?
Clipped head nail are not accepted by code here at all. So what should one use to fasten sheathing ? 2 3/8 ring shank nail
First there was waferboard
remember how it swelled and disintegrated ?Then they improved that and called it OSB
it only swells at cut edges unless it gets fairly wet
and doesn't totally disintegrateThe next generation is Huber's Advantec ( google for info)
it will not swell or delam in any way
We have had water and ice on Advantec floor s for two or three months with absolutley no problems. It is the advanced adhesives and pressure gluing methods they use. It does not allow water penetration.Full head nailers are the way to go for solid nailing.
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I would go with plywood for the floors , osb on the walls & roof. Plywood 3/4 tongue & grove holds up better to weather & it holds fasteners better then osb. Osb 7/16 or 1/2 on walls & roof are sufficient enough as long as it is stapled on.