Mysterious tap-tapping on new modified bitumen flat roof

Greetings from Southern California. Hopefully someone can help me with a weird tap-tapping/creaking metallic sound that occurs at night in one spot on my new flat roof. I’m guessing it’s some sort of weather-related contraction, although it’s not exactly cold-cold here. We’re expecting a low tonight of 48.

Details: New torch re-roof over back house flat roof of cantilevered, 2-story wood and stucco house built in 1965. Two existing layers down to the plywood deck were torn off. Plywood was said to be in good condition. Contractor installed a base sheet with metal cap nails, and then 12 sqs of Polyfresko G.

It definitely stopped my leaking problem, but now the noise keeps me awake at 4 a.m. I hear it above me in one room, but not in others or near the chimney, and not when I venture outside onto the patio. It’s a regular kind of tap-tapping, maybe 3 taps in a row, like dripping water, then silence, then resumption. I wouldn’t say it’s super-loud, but it’s notable when everything else is quiet. It seemed to taper off about sunrise and I’m pretty sure it doesn’t happen during the day. The house does creak a lot being perched on a hillside, but it’s usually one-off creaks along the walls. (I do get owls and so on, but this is different, too regular for wildlife.)

I emailed the contractors this morning; no response yet, but they are pretty busy and normally very good about emails. I’d just like to present them with some professional opinions in case they think I’m crazy. They already returned last week and checked to make sure the flashing was all secure. Many thanks in advance.

Isolating the location as best as possible will greatly assist the contractor. It almost sounds like a flapper on an exhaust vent possibly servicing a bathroom? The evening cools, breezes start to stir and air pressure imbalances inside the home make the flapper tap several times till the pressure is equalized. If the roof was replaced, is it possible a new vent was installed therefore creating a new sound which has replaced an old sound you had learned to ignore? Or, it could be a demon?

Thanks for the advice. I’m not sure about a new vent. I will ask. I’m confident the contractor did a good job, so the whole thing might be some unintended consequence like that. If the vent is above the bathroom, I will definitely zero in on that area tonight. Demon? Like Gene Simmons? Feasible. (I didn’t go on the roof. Too scary for me.)

Was polyisocyanurate insulation installed over the wood before the finished roof?

Someone mentioned insulation in a previous noisy-roof thread, which made me wonder. I don’t see any reference to it in the work order. Again, I will have to raise this issue. Assuming it’s a no, what are the issues? Thanks! Info contained on Polyglass warranty:

Polyglass base - mechanical method; Polyfresko G - heat weld; Detail and repair finish - brushed.

Deathwatch beetles could be the problem.

Fantastic. The things I wish I didn’t know! I looked at a YT video, in which it had more of a machine gun rat-a-tat. But I don’t know if there are different versions.

Amazing, a small beetle’s desperate plea for help, for belonging, for … LOVE! There is only one solution any responsible home owner must act upon! A mate must be found for this longing beetle … for the beetle’s call will not be silenced until it’s heart is stilled!!

A can of Raid should do the trick!



Being cold blooded, temperature will regulate the tapping. Kinda like temperature by cricket chirps.


Ouch! Is this still a roofing forum or have we devolved into Shakespearen theater?

The rep just replied (on a Sunday) to say it may be the roof sheathing expanding and contracting with temperature fluctuation, and he reaffirmed that when the techs returned recently everything looked good and the “roof was tight.” I will ask about the exhaust vent.

The roof sheathing creaking … and after a new roof huh? A pretty wide and sudden temperature fluctuation might trigger that but you’re likely in your cooler season, am I correct? Sounds to me like one of those excuses that are difficult to challenge, invisible, and conveniently dismissive.

Maybe someone else might disagree and offer something more “believable”?

Well, yeah. Lame excuse in SoCal. This week’s forecast gives me a maximum one-day range of about 17 degrees - tomorrow - with 51 to 68. (Not meant as a brag!)

Sorry to reawaken an old thread, but maybe this will benefit others. I believe it’s copper pipes inside the wall. They rattle at the slightest breeze - right next to my bed. Not sure how the breeze gets in, though. I assume they got inadvertently loosened by the roof demo, which shook the house for a full day.

Stlll thinking it’s a demon…