New felt - pooling?

pacman8

Hi,

Had a new felt put on my flat roof extension. Ply + insulation underneath deemed to be in good condition so those remained. Noticed after it rained a bit of pooling in 2 spots. Raised it with roofer and was told that generally you'll have some surface water on a flat roof and it's nothing major to worry about. Thoughts?

Can't post link to image as a new user so have put a space between https and :.
https /imgur.com/a/2ueHcVF

Davesnave

https://imgur.com/a/2ueHcVF

tonyh66

interesting job your going to get hollows on an existing base, the one near the seam would be concerning if the seam hasn't been sealed properly, the other one is ok should evaporate over time. Im not a roofer so don't know whether the seams should overlap or just butt together like they are, im also guessing there is another layer of underfelt under that top layer which would make the butt joints ok. Im surprised there is no pooling near the edge where there is a pronounced ridge.

pacman8

Yeah, there is a layer of underlay underneath. Also, there is a certain amount of overlap of the mineral layer such that when the two layers are squished down, the black liquid (tar?) oozes out creating the watertight seal.