Ice damming is addressed through insulation, ventilation, and sealing air leaks, regardless of the roof material.
For a 1:12 pitch roof, the only appropriate metal product will be a mechanically seamed standing seam. It would work very well for you.
Todd Miller
2014-10-04 16:19:18.000000
I need to get my roof redone. It's a 60 year old house with a low pitch roof (1:12).
I'm going to get the plywood replaced, and insulation blown in to r45 while it's off. Will be redoing gutters, getting vents fixed, etc.
My preferred contractor is trying to argue me out of metal - he says that there can be issues at the end of the roof when it freezes, leading to water forcing the seams apart. Is there a standard technique that prevents this from happening? (He, by the way, advocates TPO.)
(And a second question - I've had quotes for metal range from $600/sq to $1750/sq. Assuming the thickness and coating is the same, is there anything significantly different that a $1750 installer would do?)
Low Pitch
2014-10-04 12:31:09.000000
Be sure to have the attic floor air sealed when the roof is off.
How is the roof currently ventilated or is it?
Tough to say where the spread comes into play and while $1,750 might be on the high side, $600 is just as easily on the low side for this type of application (i.e. mechanically seamed standing seam for a low pitch).