Maybe a silly question but how would I know if I have soffits in my home? I do see the plastic covers on the underside with the little holes. But when I look closely it appears to be plywood behind it. So I checked a few spots and when I push the plastic up i only see plywood through the holes.
Sofit are the plastic covers with the holes, that is vented vinyl sofit. I think what you are asking is how do you know if it is truly vented. Typically if vented vinyl sofit over old solid plywood sofit, the installer will drill some holes for venting. You will probably need to remove a few pieces to see if they holes were drilled.
Yes that is exactly what I am asking! I am kicking myself now because I had two opportunities to check while they were replacing my roof. Once when the plywood was off (could have just waked the edge and if need be just drill down) and second when they were replacing the facisa boards when the aluminum was off. Could have just slid them forward… They installed a ridge vent, I take it the holes would make this roofing system more efficient?
If they arent any holes drilled, what diameter drill bit should be used?
Also my house is cantilevered and it has those plastic soffit vents under the cantilevered sections. I know for a fact those are not vented. Should they be?
For best practices they should be vented. Have worked on plenty of houses over the years where it was impossible to vent the sofit or there was no sofit to vent. Ridge vent without sofit vents is better th than nothing in my option but will not be working to its full ability without them.
In plywood I normally use a 2 or 3" hole saw or a circular saw of the sofit is big enough. If the sofit is solid wood normally use a 1’-1-1/2 " auger bit and make more holes. Pretty much comes down to whatever you can safely drill upside down standing on a ladder. Have seen guys using 4" hole saw and when it gets stuck almost throws them off the ladder.
Venting requires alot of things. You can drill as many holes as you want but if the bays are framed off, insulation is installed incorrectly, it’s not going to do any good.