I have a new white oak timber frame with SIPs around all exterior walls. The frame and Panels were constructed fall of 2005.  The SIPs have come loose, screws sheared, and SIPs are bowing outward 1 3/4" to 1 1/2" pretty much the entire way around the house. HELP!!!!!

Candyo: I am a SIPS rookie, but I do know my woods and I know WO to be one of the toughest, least giving wood there is. I suspect your frame was green when erected, and it has now done what it wants to. SIPS, sheetrock, 1" pine, whatever will not stop it. Once it has finally settled (and it will), I would recommend pre-drilling and using over-sized fasteners because dried WO will snap them off (as you now know) . I'm sure some of the SIPS pros around can help you with the rest.
Good Luck!!
John

I have to agree with John. White Oak is one of the hardest wood there is. I was told by several Saw Mill guys not to use it for anything but the posts in my barn. I had a tough time with lags and other fasteners. You have to lubricate nails just to get then in it. I was also told that is the reason they use pine for many Log cabin applications. Pine has more flexibility which in turn adds to it's ability to bend instead of break. I am considering a Timber frame and these are things I'm sure should be considered.
Anyone with more Timber frame info and structural help, please assist us.
Thanks,

Marc

candyo -
Can you post some pictures of what's happened?

I also built a White oak timberframe wrapped with urethane SIPs on the walls and roofs. The frame and panels have been up for seven months with no indication of separation. If it happens, my exterior stucco will probably come apart.

I am frankly surprised by this. Many timberframers use white oak, especially in the midwest where it dominates as a hardwood species. Riverbend (a prominent timber frame company) uses this species extensively. Almost all of the companies wrap their frames with SIPs.

Have you seen significant movement/twisting of the timbers? Is there significant checking?

John Cannon was right if the oak was properly air or kiln dried the oak would be stable. You need to go back on your timberframe supplier

I don't know about Timber Frame. I do know that White Oak is one of the hardest species. Red Oak is not as hard.

Chris -

Few timberframes are air or kiln dried since the green wood is easier to work with and it's expensive to dry.  Those who buy dried frames usually have a good bit of money to spare.

Even pine, doug fir, hemlock and red oak will check and twist.  I have not read any testimonials of this happening before with a timberframe/SIP combination.

candyo - Go to http://www.tfguild.org

Here you will find a wealth of knowledgable people that do nothing but talk timber frames.  You will likely get some help there.  If you can, please post some pictures of the frame and the panel problems.

Using ANY green timber material increases the chance of movement as the drying process continues. I would bet that the oak frame being discussed was installed with a high (over 40%) moisture content. I encourage Candyo to contact his timber framer and get information about the source and history of the oak used in his frame, as that would be the most likely source of his problem. I believe that John Cannon's "fix" is probably the best and only solution.

candyo, I was wondering if the drywall was applied to the panels at the factory or was it installed on site?