[fiveightandten]

It's roof time for my 2,000 SF colonial, built in 1988, which has only gable vents. The house has wood soffits (no vents). We have an air handler / heat pump in the attic for AC/heat. I'm located in Connecticut, so snow / ice is a factor.

Contractor #1 says:
Certainteed Landmark over "Certainteed synthetic underlayment" (unspecified)
Certainteed Ridge vent
Certainteed Intake vent along eaves
Contractor says: "This is the right way"

Contractor #2 says:
GAF Timberline HDZ over GAF Feltbuster
Install solar powered exhaust fan in center near the ridge and leave gable vents open as intake.
Contractor says: "This is more than adequate, eave intakes look awful and you'll have a hard time ever selling the house with them installed, cutting soffit intakes is too intrusive and costly"

Contractor #3 says:
GAF Timberline HDZ over GAF Feltbuster
GAF Ridgerunner exhaust
"Circular intake vents" installed at soffits (unspecified size, but definitely will not balance NFA with Ridgerunner).

#3 is cheapest, #2 is an additional $3K, and #3 is another $3K above the middle guy. It seems #1 is the only one doing this right. But can anyone provide some insight on this?

 

[roofermann]

1 and 3 are correct with having intake at the soffit and exhaust at the ridge. 2 is risking ice dams without having cold outside air coming in at the bottom, where the warmth from the house is closest to the underside of roof.

 

[fiveightandten]

1 and 3 are correct with having intake at the soffit and exhaust at the ridge. 2 is risking ice dams without having cold outside air coming in at the bottom, where the warmth from the house is closest to the underside of roof.

Thanks for the reply. I kind of figured #2 isn't right about their venting, but he's very adamant about it being the best approach. And his opposition for eave venting has me second guessing Contractor #1.

I'm skeptical of #3 as well. We have 7" soffits, allowing for max 6" diameter round vents.

• The attic is 40'x20' = 800 SF. 1/300 rule calls for 2.66 SF (383 sq in) minimum NFA.
• 40 feet of GAF Ridge Runner (at 12 sq in/ft) = 500 sq in NFA.
• 6" sofft vents have 5.5 sq in NFA. So we'd need 45 per side to balance with the exhaust vent. I doubt he's planning on this, as it would turn my soffits into Swiss cheese.

I'm not sure if I'm off base here.

 

[roofermann]

Look into a strip vent for the soffit. Example here; Continuous Soffit Vents - Air Vent, Inc. other manufacturers have similar

 

[fiveightandten]

Look into a strip vent for the soffit. Example here; Continuous Soffit Vents - Air Vent, Inc. other manufacturers have similar

Thanks, I think roofers don't want to get into installing a continuous vent, hence them avoiding it. Unfortunately it's not something I can DIY as we have a walkout basement, so roof in the rear is 3 stories above grade. I don't have ladders that big, nor am I comfortable with it.

I could retain a separate contractor to install continuous vents. Though, do you think that would lead to finger pointing if we had any issues?

 

[roofermann]

The one possible issue is that the soffit airspace and attic airspace are blocked from each other by framing, a possibilty on older homes (pre '70's). You would have to look into shingle over edge vent or vented drip edge, both of which can be installed as part of the re-roof process.

 

[fiveightandten]

The one possible issue is that the soffit airspace and attic airspace are blocked from each other by framing, a possibilty on older homes (pre '70's). You would have to look into shingle over edge vent or vented drip edge, both of which can be installed as part of the re-roof process.

I believe the soffits are contiguous to the attic (1988 build date), as our bathroom fans are vented through soffit-mounted vents. Though the fiberglass roll is tucked in there. I haven’t pulled it back to have a look, and it would need to be dealt with to allow for soffit intake air flow.

I believe the Certainteed intake that Contractor #1 specs is shingle over edge. We’re doing some referral drive-bys to have a look. But it’s rare around here in CT. Do those systems do ok with snow and ice?

 

[roofermann]

I haven't had much experience with the shingle over type, so can't really give an opinion.