damn osb

[FrankInWIS]

put up osb last week.  when we returned this week, after much rain.... I noted the lowest parts of the walls was actually swelling and distporting already from the slow drain.   I bought treated plywood and for the parts of the walls that wern't sheeted yet, I put the first 16 " with the treated.  I liked how that worked out and it really tied in my sloppy stud and sill structuring together nicely and with something that will hold for many years.... I hope. (See ladder....and lower left wall)

[glenn kangiser]

An apartment complex I worked on had OSB floors.  They had to drill holes to make it drain faster and sweep, pump and swish water out with squeegee's.  After about 6 months of off and on rain, the foreman said they were getting to the point they may not take much more.  They did get away with it though.  Some places swelled about 1/4"

[Redoverfarm]

Apparently you all do things differently there with your "osb" . In the east we usually frame and then do the roof with a temp covering (titaninum felt or felt paper). Will use osb on the corners but the majority is attached once the roof is in place to shed the water.  And if you are like most DIY'r (me included) use Advantex or simuliar floor to hold up until the roof is on given the time period that it usually takes.

[John_M]

You may also want to find a way to get the water away from the base of your structure quicker.  Maybe the photo is misleading, but it looks like that soil is pretty close to the lowest layer of sheathing.  When it rains, that water will splash and up onto the walls and constantly keep it moist which may lead to issues in the future....just a suggestion.  

Good luck with your project!

[FrankInWI]

good point about protecting the lower edge of the sheating with something to prevent the spashing from getting to it.   Yeh, I expected to get the top on faster....but the days just fly by and the progress is slower than I hoped.  We'll get er done before snow flys though... I hope!  Deer hunting coming and it's against the law   for men here to do any work during the gun deer hunting season.

[Redoverfarm]

Yep deer season plays havoc on Construction. I had block layers last year that lacked 4 courses on a fireplace. I was going to pour a cap in the afternoon during the week of deer season. They were leaving on Thursday before and said they were not going to return until the week after the first week of deer season.  I told them not if they expected to get paid. One did arraign to come on Sunday and finished in about 4 hours. Got my cap done that week.  I hunted religiously for 25 years but sometimes I do find things more important now days.

[TheWire]

Frank,

I know you probably have the heck nailed out of the OSB close to the ground, but you really want to avoid non treated wood within a foot or so of the ground.  While I'm not a building code pundit, http://www.legis.state.wi.us/rsb/code/comm/comm021.pdf section 21.10 has some information on minimum clearances to grade or cement.  While the codes go too far at times, they also have a lot of good points.

If the OSB is 1-2" within the ground, even when the siding is done, the bottom could get wet from rain splashing, landscaping, or be an easy target for bugs.  Your idea of PT plywood for the first 16" is great.  If you set a circular to 1/2" you should be able to cut the OSB up 16" and break it away from the nails then finish with the PT plywood.

[glenn kangiser]

Looks like you could pretty easily lower the dirt a little too if that would work out better.

[Redoverfarm]

Frank

They make vinyle lumber that you could substitute for the lower portions that are prone to getting wet.  Is this a slab construction or is there a rim joist?

[Erin]

You might also consider just painting it with multiple coats...
My dad built a cabin 30 years ago with OSB as the outside sheathing (no siding, etc).  It's completely exposed to the elements except for the multiple coats of paint.  
Though it's a pier foundation and the OSB doesn't even come close to the ground...