Could someone offer some advice on how to vent the soffit under the eaves of my house? I am not a construction professional, I just like to read FHB and FWW and do it myself.
My house is a brick on block masonry house built in 1959. I was going to add rafter vents (or baffles) before adding a thick layer of blown-in insulation in my attic. Since the baffles are supposed to be placed near the vents in the eaves, I first wanted to determine how the eaves are vented. The eaves on my house (which is sort of modern with a hip roof and gutters on the full perimeter) are 30 inches wide, and the soffit is a corrugated looking vinyl (that is, it has grooves about every 4 inches, probably to stiffen it) and at 4-foot intervals the soffit is ventilated. I tried to poke a coat hanger up through the vent holes so I could spot the vented area in the attic, but apparently the holes are not functional. If I push up on the soffit at any point I meet solid resistance, so I think what I have is vinyl soffit installed over the old wood soffit. I suppose the reason was to avoid maintenance of the wood soffit.
It appears that my attic is completely unvented from the botton, although it does have vents in the roof. It seems to me that the best way to fix the is to add vents in the soffit. Home Depot carries a vent that is 8 inches by 16 inches and is basically a flat piece of aluminum with vent fins and a screen on top to keep out bugs. How do I intall these in my soffit when the soffit has a corrugated pattern? This will cause the soffit to hang down below the edge of the vent. The only idea I have is to carefully cut a rectangular hole in the vinyl soffit with a utility knife, frame out a shallow box that I can tack to the wooden soffit under the vinyl, and then screw the vent to the shallow box. Would this be a good solution, or is there another type of vent that is made for use with this type of soffit? I suppose I could also pull down sections of the vinyl soffit and cut a hole in the wood soffit that is immediately above the vents holes in the vinyl, but this sounds like more work to me. Any comments would be greatly appreciated!
Sorry this post is so long.
Replies
It is possible that it was just the places you probed that were unvented -- that the vent holes line up with cutouts in the plywood in other areas. Keep in mind that it was typical 30-40 years ago to only put one 8x16 vent every 20 feet of so (though this was insufficient to begin with, and placing the vinyl over it further restricted airflow).
I'm not sure what the best solution to your problem might be. One possibility would be to find soffit liner that matches the profile of yours, cut out lengths of it that encompass a vented section, cut out a vent on the existing soffit, the fasten the new section over the hole.
Others may have other suggestions for this (all too common) problem.
Installing the baffles is another problem. You don't say what the slope of your roof is, but in lower slopes (eg, 4/12 and shallower) it's pretty much impossible to crawl in and just staple up the baffles (especially as you get older, less limber, and of greater girth). So some approach is needed that will permit installing the baffles "remotely".
DanH,
Thanks for the helpful comments. I tried probing the soffit vent holes at several locations, but not all of them. I believe the point you are making is that they could be few and far between. I will check each ventilated area. Great idea.
I know what you mean about the baffles. I don't know what the pitch is of my roof, but it is very low. Any trip to the attic is miserable. I did try lying on my belly on a piece of plywood and I think I can manage to get close enough to insert the baffle over the top plate and get a few staple into the roof. Sounds like a unpleasant way to spend a day, but I have only 4 inches of insulation in my attic!
Thanks again.
I don't know what the pitch is of my roof
If you have a 2' level handy, before going the attic, put a couple pieces of tape (masking, electrical, probably not skotchtape) 12" apart, with one 3-4" from one end. Now, flind a handy spot in the attic where you have a bit of room. Align the "short" mark on the level on a handy rafter at the rafter's bottom edge. Pivot the level until it is level. Take your tape measure and measure up from the 12" mark to the bottom of the rafter in a reasonably plumb way. Make sure the level still is, trust me, then read the distance. It will likely be near an even number, like 4" or 6" or the like, So, 3 3/4" is probably 4/12 pitch.
Or, you can go down to sears where there's spiffy electronic marvel that will read angles in degrees, slope, and pitch. This can be easier. Especially if you do not have a selection of levels and the like handy.
I believe the point you are making is that they could be few and far between. I will check each ventilated area. Great idea.
Now, some of the vinyl soffit people were infamous for not worrying about things like vents. I've seen some installs where they just screwed that retangular vent you have seen right to the face of the vinyl--which is hack work, but, it happens. You might, given the vintage you describe, find about 1" holes every 36-48" for round vents which we then covered by the vinyl.
Really, if you are in a climate where attic ventilation will help (I'm not, not this far south in Texas), you really need vents almost every rafter bay, if small. You need to balance the "intake" to the exhaust for this.
Speaking of, where is the soffit air to go? Ridge vents; turbine vents; "mushroom" vents--you said "hip" so gable vents are out.
Your location can matter, as will your experience with some of this work. This is where filling in a bit more of your profile can help us here help you. There's a handy button for this, next to the Taunton logo above the huge blue banner at the top of the screen, reads "Update Profile"Occupational hazard of my occupation not being around (sorry Bubba)
The vents on my roof (I think there are something like 4-6) are the square aluminum ones (about one foot square) that sit over a large round hole and partially slip up under the shingles.
I am located in Cincinnati, Ohio. In case you don't know the area, we are not in the snow belt like Cleveland. We get everything from the lows of 0-5 degrees to highs in the 90's, or even more extremes on occasion.
This is kind of frustrating because I really need to add some insulation to my attic, but I need to get the rafter baffles and vents in before I do anything else.
Do you think the vinyl soffit was not original to the house when it was built? A two-garage and a covered porch were added at one point, so maybe this was when they added the vinyl soffit.
Do you think my idea of framing in a shallow box and then adding the metal vent is a non starter? It seems like it work, but I guess it might look odd. Maybe the best approach would be to pull down some of the soffit and cut a hole where the soffit holes are?
Generally speaking, if the vinyl soffit were original there wouldn't be any plywood above it.Would help to know the age of the house. Vinyl soffit wasn't common until maybe the late 80s.
The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness. -John Kenneth Galbraith
That certainly makes sense.
The house was built in 1959.
Do you think my idea of framing in a shallow box and then adding the metal vent is a non starter?
Not so much the idea, as the scope.
If we go by code recommendations, you need about 1:150 ventilation. That's 1sf of vent for every 150sf of attic--that could be several dozen of those rectangular vents, which would be a lot of those boxes you are thinking of.
You are only getting .88sf per 8x16 at maximum, generally really only .75sf per. That's better than 4" round ones (1/12sf each in round numbers--about one per stud bay is a lot of 4" holesaw cuts). Note, too, that your exhaust venting (the high mounted venting needs to be half your 1:150 total as well, to get any realt effect in pulling air into the attic and out again.
With either, you lay a bead of sealant around them, that ought to keep the bugs from slipping under the lip of the ridges in the vinyl.
Occupational hazard of my occupation not being around (sorry Bubba)
Since you are very helpful, I thank you for your replies and I will pick your brain one more time.
One thing I thought of today. I have a screened-in porch with a plywood ceiling. The porch and the garage were additions to the house. There is a large irregular opening (I am guessing 4 ft. by 3 ft.) in the original roof of the house that opens into the space above the the porch. Couldn't I put some of the mesh vents in the ceiling of the porch? That way, whatever I do under the soffit, I would have to do less of it because of the porch vents. Also, there is a set back in the middle of my house such that there is a wide expanse of soffit above the front stoop. There are two fairly large areas of vented vinyl soffit over the stoop. I think I could remove some of the wooden soffit that covers up the holes in the vinyl soffit as there is some access to this area from the attic.
I see you point about sealing around the boxes I was proposing to install in the soffit to hold the vent. The vinyl might also tend to sag.
Would your main approach then be to take down sections of the vinyl soffit, cut holes in the wood soffit above the holes in the vinyl soffit, and re-install the soffit? Could taking down the vinyl soffit and just having the wooden soffit also be a viable idea? I am not sure why they covered up the wood soffit unless it was to reduce maintenance. I think wood would look better as long as it has a good coat of paint.
be to take down sections of the vinyl soffit, cut holes in the wood soffit above the holes in the vinyl soffit, and re-install the soffit? Could taking down the vinyl soffit and just having the wooden soffit also be a viable idea? I am not sure why they covered up the wood soffit unless it was to reduce maintenance. I think wood would look better as long as it has a good coat of paint.
In slightly reverse order, painting soffits is a special sort of perdition right up there with hanging ceiling drywall without drywall screwdrivers. Mind you, back when i painted for a living, here in Texas many, many houses are brick veneer with wooden soffits and fascia. The paint is neglected for decades and then the budget only allows for ten or so gallons of paint, including primer. The painter then finds that the fascia, hidden by the gutters is in as bad a shape as the soffit.
The homeowner eventually gets tired of painters ruining the vacation budget, and hires less-than-low bidder to install anything that prevents painting. <sigh>
Now, there is going to be a dance in what you do ere. If you just layout a nice, even distribution of vents on the existing soffit, Murphy will insist that some majority of them will land either on rafters, or on the lookouts supporting the soffit.
So you'd likely wind up taking down a bunch of the vinyl to finagle wher to reinstall it--which also meand you get to pick the where for te cuts, which makes the support part middling easy.
Now, you probably can use the porch, but not the garage for additional intake venting. Note, we still need to cipher up the exhaust venting--you are very likely to need a lot more roof vents to go with the soffit vents.
Or, if you have enough ridgline, you could just install ridge vents.
If, since you are on the cusp of replacing the vinyl anyway (almost being an evil, evil, word), replacing it with continuous soffit venting is an excellent choice. If you have the soffit dwn, you are going to have much better access for the low end of the rafter vent chutes, too (and you have access to see if there is blocking between the rafters--a lovely thing to find on older houses right in the way of the venting path . . . )
Another continuous option is to change how the brick mould interacts with the soffit. There is a quite nice product, coravent. You wrestle the existing trim out, nail the corovent in its place, then (re)install trim over the corovent. The vent material comes in several thicknesses and widths, the tubes formed by the corruagtion pass air but not bugs (generally). The material is black, so is mostly vanishes into the shadow line if you use a 1/3 - 3/8" reveal (the trim wanting to be wider or lower than the vent).Occupational hazard of my occupation not being around (sorry Bubba)
Thanks again.
easier way to check if its vented is to have some one shine a search light onto the underside of the eaves at night while your up in the attic, they can scan the entire perimeter in a couple of minutes, you'll see light between the rafter tails if and where it is vented ..
When you say: cut out a vent on the existing soffit. Do you mean cut a hole in the wood soffit and cover it a section of vinyl soffit with vent holes? Would I need to attach a metal vent to the hole in the wood before I cover it with the vented soffit? This might make the hole in the wood tighter against insects.
Cut a hole through the vinyl and wood, then cover it with a piece of matching vinyl (if you can find vinyl with the same profile as the old. No need for the metal vent covers -- just secure the vinyl with 6-8 short cabinet (pan-head) screws.
The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness. -John Kenneth Galbraith
what about circular vents? hole saw....pop it in between corrugated parts and you are off to the races.
It would take a lot of them to do any good.
The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness. -John Kenneth Galbraith
I am not sure about the exact airflow required without looking at his roof but you can get them in all different sizes. I
It would take a lot of them to do any good
Yep. 12 per needed sf of soffit venting.
But, then can work well at the task. Just behooves a person to hit up HF for a handfull of cheap hole saws, first, some days.
Can be nice, though, with exposed rafter tails and all, to have them in the bays between the rafters. Or, it's les work than cutting and fitting continuous venting between each and every rafter. Sometimes.Occupational hazard of my occupation not being around (sorry Bubba)
Vinal soffit has to be removed to find out for sure what you have. I know that is not what you wanted to hear, but....
Thanks. Is that difficult?
nope. Just pull, not more than a couple of nails holding it.
More of a problem reinstalling.>G<