Building first home

OSB swells , sometimes significantly , if it gets wet during the build , and it is essentially ground up sapwood , we call it beaver puke .

It moulds fast , in our area it is not significantly less expensive than 1/2" standard plywood .

The OP and myself live in the temperate rainforest region of coastal BC , it WILL rain on your frame before you get the roof on .

 

Rainscreen is code here , and in my experience , I haven't ever had a spring back issue with FlexWrap , although we did have some problems with Typar's equivilent to Flexwrap

 

I don't know about other methods of construction, have only seen 2x6 and some of these icf homes up here. Majority are 2x6 as that's basic code requirement.

Another factor is our snow load. 112.7 Psf ground snow load. Combined with whatever the rain factor is. Things have to be engineered pretty sturdy up here.

 

X2 get yourself some good 5 ply CDX 1/2" and be sound.

 

For some reason I was thinking north east. Not BC, dont know what I was reading. Yeah it would be a bitch to try and keep the OSB dry during construction. Out here in the desert its prime for use. Im sure their are manu's that will do SIP with ply sheathing.

 

We've seen a lot of issue with mold where the Tyvek product pulls away from the bottom corners in window installs, after install. The problem comes when expansion contraction, or shoddy application, and the corner of the window punctures the flexwrap and water can then get behind the moisture management system and into the walls, or trapped.

 

If OSB is so much stronger than plywood , why are all our site built seismic shear and portal walls spec'ed to be framed of plywood and not OSB ?

 

Your truss manufacturer will factor in the snow load when designing your trusses .

 

Is this construction all happening up in BC? If so your answer to me will anwer your own question. The market value to the area and again climate as you stated ealier.

 

Aye OSB is not stronger than Plywood. Also, it shouldn't get wet during framing tho most manufacturers allow a certain time of exposure before it has to be covered up. Weyerhaeuser makes a product for floors, edge gold, that resists moisture wicking and has a way longer saturation point.

 

Yeup they will do your live load and dead load according to snow fall of the region. However, if you are going to expand the ext walls to code 2x6 then you will have overall dimension shifts. The OP OG plans call out for 2x4 ext walls.

 

I would suggest that is more poor detailing , and again , a drained 10mm rainscreen cavity between the paper or housewrap and the back of the siding is code here .

 

Also, the green aspects of OSB are debatable and really relies heavily on the manufacturing processes to be considered green.

 

You spec seismic shear walls sheathed in OSB ?

 

did an elevated 600 sq. ft. cantilevered tree house employing this wall usage, but that is a discussion for another thread.

 

Yes , I have

Simpson Strong walls are designed to reduce the amount of wall it takes to provide the desired lateral resistance , their use has nothing to do with whether OSB is as strong or stronger than plywood

 

Isn't that intended for use in areas where they don't shear the whole house? In the pacific NW and in Canada the whole house is sheeted top to bottom. I thought shear walls like Simpsons were intended for use on the corners or around openings to regain shear.

Anywho, it hasn't and won't catch on out here. Other than engineered floors almost everything else out here is framed with wood and sheeted.

 

Interesting .

No issue with the nails pulling through the OSB easier than through plywood of a comparable thickness during a seismic event ?

 

See my post