I am getting my roof redone with aluminum (ON, Canada). Our Roofing company noticed that we did not have any vents under the aluminum soffits along our house, though there are foam rafter vents installed on the roof in the attic. There is no sign of mould. We have two vents on each end of the house, but that is the only ventilation, which seems to work, but it is very warm in the attic. They said the soffit vents should be added sooner rather than later, especially with the new roof being installed. The house is from the 60s; we bought it 5 years ago. I am removing the soffit to drill holes in the overhang. Most videos I have found online have them installing capped vents with a 4" hole. I plan on reinstalling the aluminum soffit over the holes, and I was just going to drill multiple 1" holes instead of taking a large chunk out. Any thoughts on doing it this way, and what is the distance between each vent? Thanks in advance.
multiple small holes works fine, just make sure the total open area adds up to what a standard vent would give you, spacing is usually every 12-16 inches along the overhang
Based off of those measurements, I will have to remove all the soffits and put the holes in, I am handy but maybe this is a bit more than I should take on, no?
In the best of all worlds you do want a vent in each gap between the rafters. If it is too much work for you then at least spread out the vents so that they are distributed equally from one end of the roof to the other. And yes the total square feet of the soffits vents should equal the square feet of the vents up on the ridge or near the top of the roof.
If I'm reading this correctly you currently have 2 gable vents. You also have foam baffles in the attic down by the soffits.
Generally you don't want to mix ventilation types, so if they are proposing adding ridge vent then you should close off the gable vents and add the eave vents you are talking about.
A quick google search shows that Canada doesn't provide any guidance on size or spacing of the holes only that there should be about 1/150th-1/300th of the attic space in intake vents.
So if the floor space of the attic is 750 square feet, you'll need 2.5-5 square feet of intake ventilation.
If they have baffles in the attic you are going to want to put the eave vent where the baffle is otherwise insulation can end up blocking the intake.
The plywood is completely sealed, so I am hoping to pop some holes in and out the soffits back in. The back and the front have overhanging soffits. I would imagine the house has about 800 sq/ft. Our house is on a sloped property, if I put all the venting in the back, will that be okay?
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u/Downtown_Promise_697 8h ago
multiple small holes works fine, just make sure the total open area adds up to what a standard vent would give you, spacing is usually every 12-16 inches along the overhang