# Flat Roof Ice Dam help



## alladin15 (Aug 13, 2009)

Our building has a flat roof that has had problems with ice dams causing leaks the past several years. Roof history is unknown as the building is over 100 years old. Current roof is rubber, with a pitch to a slightly off center scupper, with a drain mounted externally. The drain/scupper freezes over causing an ice dam, which results in flooding in the roof below. Looking at the scupper/drain I do see that the enclosure is not level, and that the drain is not flush. I observed the drainage during a thaw, and water was only flowing on the far right side of the scupper, water then would pool on the right side of the drain opening until the level rose 1/2in or so and would flow into the drain. 

Clearly, the drain and enclosure will be repaired to make it level. At night the roof is warmer than the air, with the roof melting the snow, and air causing it to freeze around the drain. My concern is that this repair may not be sufficient, and the drain could freeze over again. 

Any suggestions on what steps and/or repairs to make to minimize the risk of future ice dams. Our temporary solution is salt tubes designed to melt ice dams. One recommendation we have been given is to use heat tape, which would require running an outlet to the roof.


Attached are pictures of the scupper and drain.


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## AaronB (Jan 29, 2005)

All flat roofs get ice on them... make sure you have a good roofing system in place and forget about the icing.


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## kelaguen (Mar 14, 2010)

AaronB said:


> All flat roofs get ice on them... make sure you have a good roofing system in place and forget about the icing.


i have a flat roof too and am trying to decide between black or white epdm and/or polyiso insulation....i recently had an ice dam that lead to my deciding to replace my rubber roofing....can you clarify what you mean by "good roofing system"? i've been researching white and black epdm as well as pros and cons of polyiso insulation, but i am still undecided...i am a new homeowner and just learning these things....thanks


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## AaronB (Jan 29, 2005)

Well, what I mean by a good flat roofing system is this... a quality system, properly applied, properly sealed, of any of various membranes/seamless membranes/seamless insulated systems, etc.

If you are having issues with leakage coming in through your flat roofing system, ice on the roof isn't the problem... the roof is the problem.

Like I said, all flat roofs will get ice on them. Flat roofing systems are designed to keep it out.


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