QUESTION: A tree fell on our roof and we had it replaced.  The roofer suggested we put in a ridge vent although we already had 3 gable vents (one of which opens or closes depending on whether or not the attic fan is on). We do not have much soffit venting, and he did not add any.
Since the new ridge vent was put in, our house feels suddenly drafty, and the heating bill has gone up tremendously.  After doing some research, I think this is because we don't have adequate soffit venting, and the conditioned air is being pulled out of the residential part of the house and being sucked out the ridge vent. (Our walls, etc. are not super tightly sealed).

When I complained to the roofer, he offered to close up the ridge vent.  Is there a proper way/ best practice for sealing a recently cut ridge vent?  I want to make sure he does it right.


ANSWER: I found your situation a little puzzling. Normally if you are going to add ridge vents or roof vents, the gable vents are closed off. Why, because the air will take the path of least resistance to exit the attic, so the gable vents have a larger opening than the ridge vent that is usually inches wide multiplied by the length of the ridge to provide the proper square inches of venting and the highesst point in the roof.

Yes it is possible the air is literally being sucked out of the home since there are no soffit vents and hence it feels colder nad heating costs are increased. If you have ice and snow build up at the eaves, then that is indicative of heat looses at the eave due to this suction effect.

To close off the ridge vent properly you would have to physically remove the vent, reinstall the wood deck that was removed and fasten it to the joists (support members), install an  eave protection membrane and new ridge cap shingles.

A cheap fix would be apply spray foam insulation along the underside of the ridge vent in the attic to seal off the opening.

Hope this helps.

All the best.

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QUESTION: Thanks so much for your speedy and detailed response.  Your volunteering here means so much to "roofing dummies" like myself!  Would you mind spelling out in a bit more detail the steps involved in reinstallation of the wood deck--i.e. how much wood, how to fasten it, what type of eave protection membrane, etc.?  Sorry for asking; I just want to be really clear with the roofer.

ANSWER: No problem, we Canadians are always polite when asked.

The wood deck is either plywood, Oriented Strand Board (OSB) commonly called press board or chipboard), or if it is a really old home actual pieces of lumber. Exterior grade plywood to match the existing roof deck thickness should suffice and should be installed resting across the joists and nailed in place with Ardox nails. Make sure the end joints rest on the wooden joists, if not, then clips will have to be installed to keep the deck from deflecting at the end joint.

The self adhesive eave protection can be from any prime manufacturer such as GAF, IKO, Johns Manville, Certainteed, W.R. Grace, Henry etc. Install a strip across the ridge and overlap it onto both sides of the roof. Reinstall the shingles with the right exposure, then the ridge cap shingles. Ensure the ridge cap shingles are installed starting away from the windy side so the wind blows over the shingles and not against the leading (exposed) edge of the shingle.

All the best and hope this helps.
A helpful northern neighbour.

---------- FOLLOW-UP ----------

QUESTION: You are a wonderful neighbor to have. And I can really trust you Canadians to know how to handle snow and ice! Thank you so much for volunteering your time and expertise.  If you ever need the skills of an editor to weigh in on anything, I'd love to reciprocate.
BTW, should I only fill in the small gap left by cutting the ridge vent, or would it be more stable to cut deeper in order to rebuild the ridge and fill in with a wider piece of plywood?

The original ridge is basically an inverted Vee. So filling in the missing pieces of deck on each side would recreate the ridge. Just endure that an ice & water shield type product is installed over the ridge and the joint of the new deck and the original so water will not enter the attic.

Install the shingles and you are off to the races. You are welcome.
D. John


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D. John Henderson


My 33 years in the building science business has involved air barriers, waterproofing, and flat & steep slope roofing systems.


My roofing encompasses commercial systems (BUR, mod-bit, single-ply) and residential applications (asphalt shingles, cedar shingles, slate and metal. I am cognizant of code stipulations in regards to FM and UL for commercial roofs.

Attended numerous courses offerd by Roof Consultants Institute, Roofing Industry Educational Institute, Factory Mutual Research Corporation, University of Wisconsin, and BURSI. Lectured for RCI and mentored at a local university for a Building Science Certificate.

Past/Present Clients
Government, commercial businesses such as The GAP, hospitals, school boards as a roof designer.

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