Was this a soffit vent?

Old 07-27-15, 11:55 AM
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Was this a soffit vent?

I have aluminum covering my soffits. I removed one section of perforated aluminum directly where my electrical service passes thru the soffit and into the attic.

When removed I see a 9x12 hole cut out of the old wood soffit. It looks kinda hacked in the wood, with a miscut. Looks like a sawzall cut.

Im thinking it was removed to allow the electrician to guide the new conduit into the attic or remove the old conduit from the attic.

On the other hand perhaps it was an old soffit vent since the perforated section of aluminum was directly over this section. Since it was not cut square and had a miscut, I am not sure if would have been a usuable hole for a vent? Its very large too?

So long story short, I covered this 9x12 hole with a piece of plywood but now that I am thinking of it.... I don't know if I just covered up a vent! or an access hole used by an electrician.

Whats the typical size for a soffit vent in an old home?

When they put aluminum over an old soffit vent, assuming there would be a louvered grill of some kind over the old vent attached to the wood, would they keep that vent cover in place and place the aluminum over it?

Sorry I don't have photos.
Old 07-27-15, 12:21 PM
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My parents' house had just a few vents cut into wood soffit. They had aluminum put over that and the contractors cut a hole about 6" across for most of the length of each soffit. That would be what I expected if you had a retrofit. That said, it does sound like you covered a vent. Can you find any others?
Old 07-27-15, 12:45 PM
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Cut in ones vary from 3-4" round, to something in the range of 6x9", to long strips, and any number of sizes and configurations in between. The only way to know what you have specifically is to do some investigation. Since the original wood is covered, the easiest way would be to look down at them from the attic, if you can get back to them. You make need a rake, hoe, or something like that to pull the insulation back, and of course the vents don't work if the insulation is covering them, so you may need to install baffles. First thing though is to see what you have to start with, so, again, I would begin by trying to access them from the attic.
Old 07-27-15, 01:12 PM
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Im thinking it was removed to allow the electrician to guide the new conduit into the attic
Sometimes doing electric old work I would cut a hole for a new vent to allow access to a wall under an eve I couldn't get to otherwise. When through I'd just install a vent over it.
Old 07-27-15, 03:09 PM
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thanks... I will have to see how many others there are and if they are cut the same. Unfortunately rooting around in a sweltering attic is not going to be possible for me until fall... so I will see what I can find from the outside.

Im wondering how spaced apart would vents be... like how many per ft. etc? Or should I expect to see a hole at every place I see the perforated aluminum (which are quite a few I might add).

If it was vent.... What harm is there in closing one off like I have done with plywood?

I did so because of the condition of the aluminum at that spot and the likelihood of animals getting in. And also because the wood is deteriorated and I have my service entrance conduit going thru that area.

And if animals were to get into that vent .... is that usually open access to the attic space or just the soffit chamber around the perimeter of the house?
Old 07-27-15, 03:31 PM
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The soffit vents should be open access to the attic, so blocking critters is a high priority. If there are many others, closing off one will not be an issue.

As for how many, it could be a lot or a little, but your guess that there is a vent at every perforated section is probably correct.

Your total vent ares is supposed to be 1 ft² Net Free vent Area (NFA) for every 150 ft² of attic floor. Take that number and divide it half high and half low.

Because the perforations do not allow 100% of the air flow, estimate by using 50% of the area of hole underneath. My guess is, you will come up way short on the recommended vent area like most older homes. But that could wait for cooler weather as well.


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