Filling an indentation on a flat roof

re: "...but thought I should ask the experts."

Let us know what they say. ;-)

Please do not confuse me with an expert.

Size matters here.

I would cut a piece of fiberglass window screen to match the pocket or the center of the pocket if it is large, lay down a layer of fiberated roof cement, embed the fiberglass and top it with another layer of cement. Repeat as necessary over a period of time, allow each layer to dry well (30 days in summer heat) before adding another layer. You have to keep the coats thin or they will crack

Once the water does not puddle, add your regular top coat at the end of the summer.

Interesting ideas... I think the idea of using old shingles would work just fine and build the dent up faster then the fiberglass screen. I will forever regret using the word "expert"...:) Thanks!

Any commercial roofing company can sell you slabs of foam designed to contour flat roofs with. Carve as needed with whatever stone-age tools you can come up with, glue down, and slap a square of membrane over it and glue it down.

I would get a roofer in to do a tear off, repace what's sagging so you have a flat roof again, and cover with the new rubberized stuff. Probably be cheaper in the long run than getting up there all the time and horsing around with fixes. BTDT. Just the "peace of mind" might make it worth it.

--Vic

I used to have a flat roof that did that. They make pumps that automatically will pump water off of roofs.

I talked to a roofer about fixing it and for another 1000 bucks (or something) he said he could fill the dips in with special thick roofing felt.

Red does joke a bit.

At least put some roof cement down and between the layers.

I have a similar problem with two garage roofs.

I heard a suggestion about cement using using something like polystyrene peanuts as aggregate (to reduce the weight), but I haven't tried is since I don't have the recipe.

If anyone's heard of such a concoction, let me know.

Cost is soon forgotten...quality is long remembered.

Jimmie

I lived in a row house (13 houses, all attached) in NYC with a flat roof for over 20 years. I don't recall my parents having a problem with our section of the roof.

Thank you all for your interesting comments. I do think Red Green's idea has merit. I would plan to spend some time cutting concentric circles from asphalt shingles, slathering each with cement as I added another one. I don't believe the problem would shift if done correctly as the roof has had the same pattern of indentations for many years. As for other fillers, the foam etc might work too but I see no reason it would be better than the shingles. I have considered a re-roofing with a rubber membrane but that would be too expensive for me right now, plus it would take the fun out of a creative solution, even if the creative solution required much more attention over time.