How far can fascia come below the soffit before it effects air flow?
derekr
| Posted in General Questions on
I’m looking to get some wood fascia and if I don’t do any cutting it will come 2 inches below the soffit, is that ok or will it reduce air flow for my vented soffits?
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Replies
I don't have any scientific data for you, but I like to spec 8" fiber cement fascia boards for a more robust look, so they are usually about 2" below our 24" soffits without any consequences to air flow, as far as we can tell.
Ok thanks, if I do a 1x8 it will be flush with my soffit and I know I didn’t want that, I wanted to do 1x9 but that doesn’t exist so I have to use a 1x10 and that will bring it 2 inches below my soffit, maybe even 2.5 inches
I don't see how a few inches of fascia overhang is going to do anything to restrict air flow into a typical under-soffit soffit vent. If anything, that overhang might help a little with wind washing by acting as a bit of a wind break (I wouldn't actually count on this though, so you still want to do the usual details in the roof/attic spaces).
Just make sure nothing obstructs the open area of the soffit vents themselves and you should be OK.
Bill