Rolled roofing on parapet wall

[mathew stouffer]

Rolled asphalt roofing installed on this parapet wall. Is this material designed for this type of instalalltion.

[John Arnold]

I hope so, because it's on thousands and thousands of row houses in Philadelphia.

[Michael Derrick]

Rolled asphalt roofing installed on this parapet wall. Is this material designed for this type of instalalltion.

yes if installed correctly. with the McDonalds I built in the 70's they used a built up roofing with the last layer rolled roofing and as long as there was a cant strip to prevent a 90 degree corner as it goes up the parrapit wall it was fine. and these were installed with hot tar mopped on over 4 layers of roofing felt, each of those mopped with tar also.

Mike

[Nick Ostrowski]

Like John said, that roofing application is very common on roofs in Philadelphia. It seems to wear out and deteriorate before other areas on the same roof surface. If it is not installed tight to the parapet walls and roof deck, the unsupported area of material at the parapet-to-roof junction is susceptible to rips and tears from foot traffic. The method of install Michael described sounds like a good practice.

[mathew stouffer]

Thanks. Instalallation was pos, plus don't see much of it around here. The sun eats it up.

[Markus Keller]

Fairly common around here too. That doesn't look like traditional 'roll' roofing as you might be thinking. Looks more like the impregnated roll membrane stuff. Forget the exact name.

[Jerry Peck]

Rolled asphalt roofing ...

Probably not. (Not if you are talking about plain old roll roofing which is asphalt impregnated organic felt mat roofing and which is not allowed to be left exposed to sunlight.)

If modified bitumen single ply, probably so (if anchored properly).

[mathew stouffer]

looked like single ply asphalt coated with granules.

[Jerry Peck]

looked like single ply asphalt coated with granules.

The best way to check (and always check if you are not sure) is to find a corner or a lap and gently bend it back - if it bends kind of like rubber, it is modified, but if it bends and breaks or tears, it is organic felt mat (that is a good test 'generally and basically speaking').

Another way is, as I recall, organic felt mat roll roofing is 34" wide and modified is 39" or more (measure lap to lap).

[Bob Elliott]

That is modified bitumen.
It is done that way or with a terminator bar.