Synthetic roofing underlayment
I’m in climate zone 7 (Canadian prairie).
I just read an article on GBA about synthetic roofing underlayment. Article stated synthetic underlayment shouldn’t be used on an unventilated roof. I believe I have an unventilated roof – story and a half house with no eave extensions (roof ends at walls, no soffits), and duraflo weatherpro roof vents. Is this the definition of unventilated?
The roofing company I got a quote from says they want to install:
-3 feet of ice and water shield protection at eave edges. This is self adhesive membrane that shields against ice damming in the winter/spring months. It also forms a seal around the nails that are installed in this area.
-Synthetic underlayment over the rest of the roof. This is a new version of tar paper which acts as a 2nd layer of protection underneath the shingles.
Based on GBA article it sounds like I should skip the synthetic underlayment and have ice and water shield (or more specifically Delta-Foxx) installed on the entire roof, followed by shingles, correct?
Also, do you recommend drip edge on the gable ends (sides) of a story and half house, or just on the front and back?
If I decide to have eave extensions added to the house (12 inches), I could proceed with the quote as outlined above – ice and water/synthetic underlayment. If i go this route, the house will have soffits but what happens at the top/peak of the house? Do I need a ridge vent installed?
Thanks a lot!
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