I’m roofing my Father-in-laws house. He currently has cedar shakes over skip sheathing (1×4’s with 4″ in between courses).
I’ll be taking the shakes off and installing architectural composition (textured asphalt) shingles.
My questions are really about the sheathing. I’ve been on similar jobs where we’ve laid the new sheathing right over the existing 1×4’s, but I’ve also been on jobs where we’ve pulled up the 1×4’s and replaced with plywood or OSB sheathing as we went. I’ve also been on jobs where we’ve bought utility 1×4’s and installed them between the existing skip sheathing to give a more-or-less solid surface.
Any thoughts on the pros and cons of the different techniques?
Thanks for your help.
Replies
Totally anecdotal from a DIY, so you should probably ignore me:
When we did this on my house, we filled in the 4" spots between the 1X6 sheathing with 1x2 cut to length to fill in the hole over the rafter. Then we used longer nails to nail solid sheathing to the rafters. In spite of the fact that we used OSB, the 1x6 underneath makes it feel very solid. For us it would have been difficult to fill in all of the space with 1x4 to make a solid surface because the sheathing had spent 30 years making those spaces pretty irregular and the labor involved in planing it down for the narrow spots wasn't worth it, but we still didn't want to rip it all off when it could be put to the use of making my roof deck more solid.
My prefered method is to install osb or plywood over the 1x. Often, the rafters are irregularily spaced (on older structures), and this method creates less sheet good waste. Also, leaving the 1x cuts down the labor and the open roof time.
we would get an extra for overlaying the skip sheathing with 3/8 cdx ply.. then shingle in the normal manner
Mike Smith Rhode Island : Design / Build / Repair / Restore
How about the roof framing? I have hesitated doing the same to my 1909 house with 2x4 rafters on a hip roof - whether the framing would handle (at least in the inspector's opinion) the added weight of sheathing and comp. shingles.