Double Layer or Single when repairing

Hi all,

I’m making a repair too my roof that is roughly a 10’ x 10’ area. The whole roof had a double layer of shingles on it before I started the repair. Is it necessary for me to replace both layers now, or can I just put one layer on the repaired section with the rest of the roof being double layers?

Thanks a lot!

if you can make it work with one layer then do it.
if you have to build it back up you can use roll roofing instead of shingles for the first layer.

good luck.


Thanks for the reply. Sorry if this sounds silly, but what do you mean if I can make it work? Currently there are a few rows of new shingles laid down, but there is a step between the layers. Is this ok?


On something like that really go find a pro. You can make anything work, but the question is for how long really. You must build the area back up or it will look really bad. If you dont think you can seam it together water tight then find a pro.

Depending on the pitch of the area you’re working (photo would be nice), a single layer replacement on a double layer section is going to

a) look very out of place (as noted /)
b) have the chance of a water leak @ the single layer to double layer dip.

As it is, you’ll probably have a noticeable issue if your top layer of shingles is 7+ years old - shading, algae stains on the old shingles, etc.

I really do think this might be one of those areas where a DIY isn’t the best approach.

Your actual “repair” will be done at the top most layer. Depending on the severity and duration of the leak you may need to go down to the bare wood to check for rot. If this is the case then when it’s time to close your repair area use pieces of new shingles to build up until you can replace the top most layer correctly and have everything looking like it was before you touched it.
The shingles used for build up can just be well fitting pieces and do not need to be laid as normal shingles would be. They are only for height, not water proofing.