# connecting new roof to old roof



## NateHanson (Apr 15, 2007)

Got a picture? That'll surely help. 

What type of roof and what pitch?


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## Ed the Roofer (Jan 27, 2007)

Did he strip off the original roof from the existing portion of the home before he installed the shingles on the addition?

Ed


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## kathyz401 (Sep 26, 2007)

*connecting old roof to new*

No, I'm sorry to say he didn't strip old shingles


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## scorrpio (Aug 14, 2006)

You gotta strip back at least several rows of shingles. The row you leave in place, pry up the tabs carefully and cut through the seal without damaging the shingles. 

Usual roof construction is sealing membrane at roof edges, (3 feet wide) overlapped by 30lb roofing paper, then shingled over. Any changes in roof plane must also be flashed. Consider the normal flow of water, layers must overlap in the direction of that flow. If your old roof edge has the membrane and it's adhered real tight, you might have to strip shingles to where roofing paper begins. If you can pry up about a foot wide strip of the membrane , it'll be easier - but it is usually adhered real tight and won't come off without severe damage. You should have aluminum or copper flashing installed over the sheathing where old and new roofs meet, and membrane applied over it, tucked under the old roof membrane or paper, and overlapping the new roof paper by at least 6". Basically, there should be a continuous flow of water barrier, upper overlapping lower and nvere presenting an entry point for water. Do not forget drip edges to prevent water intrusion at sides. Then, you shingle it starting at the bottom. Tuck the last new row under the original row of shingles, nail, and seals original shingle tabs down on the new ones. 

Then you should have a sound roof connection. You can't take shortcuts with a roof.


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## Ed the Roofer (Jan 27, 2007)

Depending on how old the original shingles are and how brittle they have become, that might not work.

Proper weaving and interlacing of shingles from one roof plane to another is one item even a lot of so-called roofing contractors can not do as properly as required.

You really should strip off all of the shingle and start fresh. That black emulsion or roof cement has to look like crud on a new addition.

Ed


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