How to get by insulation blocking soffit vent

Old 06-03-01, 03:35 PM
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Being down here in Texas, I am often pelted by the blazing sun, which can be downright uncomfortable. I have it easier than the blower unit for my A/C system, however, becuase it sits in my attic during the summer and suffers through temperatures that would kill me in minutes.

Being and nice guy (hate to see a peice of machinery suffer) and one who wants to save on energy costs, I thought I would improve the air flow in the attic of my four year old house by working on the soffit vents. My builder, you see, seems to have placed a fairly minimal (11) number of the smallest (16x4) soffit vents on my house just to make the code people happy.

To my horror, I've discovered that a design flaw in the house makes most of my soffit ventilation basically just window dressing. You see (picture this), the rooms on the right and the left side of the house all have a section of their ceiling that follows the roofline of the house. Thise forms about a 6-8 gap that runs the last 3 feet of the roofline as you approach the edge of the roof. The only way for my builder to provide insulation for this section of the roof was to fill that channel (the 6-8 gap, 3 foot long, about 24 inches wide between the rafters of the roof) with a nice big piece of fiberglass insulation. One one hand, it nicely insulates the ceiling of the house. On the other, it blocks the only air channel between the soffit vents and the rest of the attic.

So, the question is: How do I open an air channel through the isulation without destroying the insulation value of the insulation itself?

The only thing I can dream up thus far involves building a U-shaped channel out of that lovely foil-covered foam sheeting they use on the sides of some better-built buildings and then sliding it down so that it rests on top of the fiberglass. Compressing the fiberglass rids it of a lot of the R-value, but I'm hopint that the sheeting would help make up for most of the loss.

Am I kidding myself here? Is that a reasonable solution to the problem or is there a much better, easier way to skin this cat?

Any help would be appreciated?


Jonathan Lent
Old 06-03-01, 10:49 PM
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I would suggest just building the vents out of cardboard , it only needs to be about a 1" air space to allow a decent air flow.. in order to fit it all the way down though so the cardboard remains in its designed shape take a 1" x 22" piece of wood and form the cardboard around it then slide both down and the wood out.

Do you have a ridge vent or roof caps?
They do have thermastically controlled fans that can be installed at the roof vents

Good luck

Old 06-06-01, 05:10 AM
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Insulman is right on - Anything to allow air flow is all you need and you have to have a vent at the top as well so the hot air can escape. Kinda like how you cant blow through a straw if the other end is plugged. Just be sure the bugs and birds can't get in. Add screen to the inside of the vents if necessary.


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