Tying(shingling) new porch roof into existing roof
#1
04-18-03, 06:45 AM
Tying(shingling) new porch roof into existing roof
I am building a screened in porch and tying it's gable roof to the existing roof on the house. The house roof is a gable running 90 degrees to the new porch gable. The ridge of the new roof falls well below the ridge of the house roof. I am having trouble finding the best way to tie the two together in the valley, as far as the asphalt shingling goes. I know how to roof felt, flash and "inter-weave" shingles in the valley when both roofs are new. However, I have never tryed to roof a new section tied to an older section. Any help/ideas would be great. Thanks.
#2
04-18-03, 05:48 PM
On your "old roof"(main) you are going to cut the shingles back so that a full shingle's edge will fall in the valley centerline. I suggest using a flatbar and a hookblade working down the roof valley. Once you cut the old shingles back 36" or less, work the new section into the old. using new shingles to run your valley. A roofing diagram is on every package of shingles @ Home Depot or Lowes. YOU WILL BE USING NEW SHINGLES FOR TYING IN YOU OLD AND NEW SHINGLES!! Hope I helped somewhat. If you don't understand something, come back and ask! Hope this helps!!
#3
04-19-03, 12:45 PM
roof
You could go to a sheet metal shop and they would make a valley for you. ,This way you cut the old roof shingles back a way pull some nails and slip it under the old shingles. The new roof shingles will just lap over the valley like you cut the old roof. The valley should have a 1/4 " turned over on both sides and in the center we put a V upside down This is what they call a storm valley. The water that comes off one roof then hits this and cant go under the shingles on the other side
ED
ED
#5
06-05-09, 06:19 AM
Fixing a gabled roof attached to old roof
this older post is exactly what I have done however thinking I knew how to do it I attached it over the old shingles. I used alot of roofing tar to seal the edge but I now have rain leakage all along the new edge instead of run off. Are the old shingles the problem? Do I need to rip it all off and redo it? But the frame is already on the shingles. Help!
#6
06-05-09, 08:44 AM
Wow, I just got an email that said there was a reply to a post I did 8 years ago. Well, I finished that project and have not had a leak in 8 years. I framed directly over the old shingles, then I cut them back to expose the original roof decking along the new framed edge. Next, run new felt paper on the new and old exposed decking. Then run flashing down the valley you have created. Tar all nail holds. Now shingle the new roof and "inter weave" when you meet the old shingles. Just taring the valley will never work. Good luck.
