Advice on extending shed shingled roof after initial build

Old 10-16-19, 07:39 AM
Thread Starter
Join Date: Oct 2019
Posts: 4
Received 0 Votes on 0 Posts
Question Advice on extending shed shingled roof after initial build

Hello everyone,

First off thanks for any advice. I haven't been able to find any good advice via Google on how to do this.

I'm building a 12x16 shed that will have a 12/12 gable roof. I'm getting ready to install the roof sheathing currently. I was thinking about installing a 12 inch sub fascia ladder on each side to give it a little overhang, but I'm wanting to eventually extend the gabled roof to cover a patio area on one side.

The piece I'm unsure about is how to handle the roof shingles when I extend the roof. I'll have to but the shingles up to the existing shingles and caulk the seam, but I'm not sure if that is the best way to go. Maybe I need to pull up the existing edge shingles to overlap the new shingles.

Just looking for advice from others on how to proceed, thanks again for any help!
Old 10-16-19, 08:20 AM
Marq1's Avatar
Join Date: Sep 2016
Location: USA MI
Posts: 9,315
Received 917 Votes on 833 Posts
So I have never done this so somebody may come along with better option but from having just built a shed this summer!

You bottom edge has the drip molding with felt, starter shingles, and shingles on top.

If you removed the drip edge and inserted flashing under the felt it would then go on top of the new lower roof!
Old 10-16-19, 08:36 AM
Join Date: Jan 2013
Location: U.S.A.
Posts: 2,120
Received 72 Votes on 65 Posts
Just build it like you planned on without the extension. You would presumably set the rafters for the extension on the same wall, so would need to remove the fascia and drip edge at that time, then run the shingles up to that point, remove the starters, and tuck the new shingles under the ones that your laying now.The only things you would want to watch is your spacings so that the overlaps blend and pick a day that's not real hot or real cold so that the shingles cooperate when you lift the old ones. Nothing complicated. Trying to bring them together with caulk though is a sure failure.
Old 10-16-19, 08:50 AM
Thread Starter
Join Date: Oct 2019
Posts: 4
Received 0 Votes on 0 Posts
Thanks for the replies. I think I may of explained the situation a little wrong. I would be extending the roof on the gable side (width of the shed), not the length or longer section of the shed if that makes sense.

I assume it would be the same proceedures as you mentioned Pedro, just pull up the edge shinges and tuck the new shingles under them.
Old 10-16-19, 05:08 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 29,074
Received 1,478 Votes on 1,330 Posts
When you add on to the roof and go to tie the shingles in, you will tear shingles back as needed to create stairstepped sequences of shingles. You tear off enough shingles so that your felt paper and ice and water will overlap 12" over the existing. Then you butt the new shingles against the existing stairstepped ones. You don't overlap and you don't caulk!

Thread Tools
Search this Thread
Ask a Question
Question Title: