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TOPIC: General Discussion

Ice

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We are currently looking to replace our shingle roof w/ a metal one. We currently have major ice dams so is there one style of metal roof that would be better over another?
Deborah Cavagnaro

1/27/2011
No. Ice damns have almost zero to do with the roofing type and everything to do with heat loss from the living space below. It is a common misconception and even amongst roofers. Ice damns are most often created from the unchecked loss of heat from the living space below and the resultant below freezing ambient melting of the snow load on top of the roof. The common recommendation is to add ventilation which will more effectively remove the heat from the attic but that does not address the causative fact - the heat loss. Have a energy auditor look at that home and tell you what can be done or at minimum a remodeled that knows his trade. A raised standing seam roof will be more effective at allowing the water from an ice damn to enter the structure as compared to a shingle roof.
Eric Novotny
An informed customer is the Best Customer!

1/28/2011
Ventilation and insulation are usually the keys to avoiding ice dams. There are also some ice melt systems available both on top and beneath the roof. One thing about metal roofing is that if ice dams due occur it is usually less prone to be damaged than other roofing materials but certainly not immune. Some metal roofs do lend themselves better to above sheathing ventilation than others and if you do not have a traditional attic space that can be vented, those products may be helpful. This would be products that can be mounted on battens rather than on sold decking.
Todd Miller
Isaiah Industries, Inc.

1/29/2011
Most metal roofs (more specifically standing seam) will not leak as a result of the ice damning but will still ice damn. They can form dangerous slides of ice that can injure and kill someone if not careful. Ventilation help prevent ice damns by removing heat from the attic and therefore the source of the melting. If you have an existing roof that has soffit vents and a ridge vent, that should be all the ventilation that you need and you other issues. The primary basis for ventilation is to control humidity and prevent condensation, mold, mildew, etc. The reason that most homes will ice damn is because of unchecked heat loss from the home as a result of a poor attic insulation layer and more specifically, a poor envelope layer (air barrier) and the mass movement of warm air from the living space below. Attic insulation does nothing to stop air loss from the living space.
Eric Novotny
An informed customer is the Best Customer!

1/30/2011