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harryc
08-28-2003, 08:09 PM
Back to my addition project. The roof of the new 1 story addition abuts the wall of the existing 1 1/2 story house. The old house was stripped down to the wall sheathing (planks) and the new framing and sheathing attached to it. The front wall of the addition is parellel to, but set back about 8 feet, from the front wall of the existing house, so a portion of the existing house sidewall is exposed. This is the wall I needed to pad out, which I will use 3/4" Homasote Ultra R. This will also be placed adjacent to the new roof, since it abuts the existing wall. The roofer has asked that I not put the Homosote on until he is done roofing, so he can flash to the plank sheathing of the old house. Next I would install tyvek, then the homosote, then the vinyl siding. This arrangement would allow water at the eave to run between the homosote and tyvek. He says this is okay. What do you think about this? I kinda like homosote against the planks, then tyvek, then vinyl. Any comments would be appreciated. Thanks.

Rich
08-29-2003, 06:00 AM
I would suggest putting the flashing after the homasote and tyvek. Depending on what type of roofing you have (asphalt shingles vs metal) will determine if you use step flashing or continuous flashing, respectively. The drawing below kind of represents what I gathered from your post with using asphalt shingles.
I don't want to tell the roofer how to do his job but I think he's wrong in putting the flashing behind the tyvek and homasote.

http://www.construction-resource.com/images/temp/harryc-roof.jpg