[Badger Hill]

On our current house, we have 2x6 walls, .5" thick felt board (not sure what it is called), and .5" thick T-111. We want to use the T-111 as a sub sheathing and put siding on top of that. The question is, do we install our windows with building paper, or what?

The next question: Is it a OK to cover the T-111 siding with building paper, thus trapping the T-111 in between the .5" thick felt board, and another barrier? Or should something be used on the outside that is slightly permeable so the T-111 can breath?

Thanks

 

[Just Bill]

Not sure about your window question. Yes, windows needs to be flashed, starting from the bottom, then sides and top. I prefer self adhesive flashing about 6" wide, but felt will work. As for something over the T-111, use tyvek housewrap. it will allow the house to breath but keeps out moisture.

 

[Badger Hill]

If Tyvek will allow vapor to pass while keeping out liquid, that would sound good for the health of the T-111. I could use the self adhesive flashing as it sounds easier to use. Our walls are 2 x 6 so is 6" wide self adhesive flashing wide enough? What adhesive is suitable and should one seal the bottom, or leave it open to drain?

 

[Badger Hill]

One of the methods on the wrapper of Protecto Wrap is to use Protecto Wrap on the bottom, then install the window, then install the wrap around the sides of the window, first on the sides, then on the top. This appears to me to be not only adequate, but the best method. Opposed to wrapping under the window and installing it with sealer.

So I'm a bit confused, or will either of these methods suffice?

 

[Gary in WA]

T-1-11 is usually 5/8" thick. It is a vapor retarder, almost a barrier (.65 permeable).
Here is some good reading: http://www.panhandleinsulation.com/buildingmaterials.html

http://www.buildingscience.com/docu...rol-for-new-residential-buildings?full_view=1

http://www.umass.edu/bmatwt/publica...s_feltpaper_weather_penetration_barriers.html Be safe, G