flat roof bubbling

[thingummyjig]

hi we have a covering on our porch and garage roof which I assume is roofing felt (its a kind of grey/green colour) just recently I've noticed quite a few lumps coming up, some quite large, bigger than a dinner plate. We've had one big lump (looks like an air bubble) above the porch for the last year or so, which i wondered if it was an ants nest as we definitely had a nest somewhere around there, every year the ants swarm from that area. The lumps that are now appearing on the garage roof definitely were not there last year. Can anyone tell me if it sounds like we need the roof re-covering? There do not appear to be any leaks at all.

[beejay1124]

either air or water blisters
for a short term fix you could slit them with a stanley knife(hooked blade best ) , fold back the flaps , clean and dry the blister hole and torch ( blowtorch )the felt down again-the heat on the back of the felt will melt the bitumen and make it stick
long term you will need refelting-just get a cap sheet done--no need for a full restripping or redecking-----going by info given

[thingummyjig]

thank you so much for your fast response! We will have to try this!