Q re Felt Paper bubbled up after rain

I’m building a woodshed that has a 8x12 ft single slope roof. I put on felt paper with 16" overlaps (snows and ice here) and flashing. so good so far.

Then i put on a few courses of 3 tab shingles but dark was closing in. Since there was rain and wind in the forecast for that nite I put 2x4’s over the felt paper edges and weights on the 2x4’s. idea was to prevent wind from grabbing the felt paper and shredding it. Next morning went out for a look see and found the felt paper bubbled up from the rain. I sure didn’t expect that because I believed that the felt paper was water proof.

So now what? do i lay the remaining courses over the wrinkled/bubbled up felt paper? or, do i rip it all off and start over?

Have mercy on me, I’m a software engineer and have never done a roof before.



Once the sun hits it you should not have a problem. It should lay back down.



Thanks. Thats what I was hoping. However thats a couple of days away.

Why does a material designed as a moisture barrier act that way? It must absorb some of the water?


Malcolm Sir:
The felt underlayment acts as only a temp waterproofer until shingles are laid, it’s main purpose is to stop moisture from gaining access to the deck and causing damage, if not used would pre-maturely age the shingles. Sounds like your on the right track, hope you used starters?? Be careful on that roof
Good Luck

Tiner “Roof”

Thanks for input. Yep… used starters. Cut tabs off shingles and used the top end as the bottom. Being very careful to not place inter tab gaps or shingle to shingle gaps over a lower level gap.