The danger of covering your roof vents

Commercial roof vents

Many homes have “whirly bird” vents or turbine vents. These vents look like small windmills and spin. The reason they are on your roof is to provide the air exchange your home needs to remain comfortable and healthy.

If you cover them, you can cause extremely expensive damage to your home!

While thinking of your home as “healthy” may not be a new concept to most, thinking about your attic ventilation in these terms might be a new idea for some people.

In the winter, it seems to make sense to cover the vents (like you might do for your external water faucets), and the covers are relatively inexpensive and easy to find, running around $10-$20/each at most home supply stores. But, like a lot of things in life, just because you CAN, doesn’t mean you SHOULD.

We know, it seems counterintuitive to let hot air escape from the attic during the winter, but that’s exactly what you should do, and there are several reasons why.

Trapping warm air inside the attic can cause condensation which leads to excessive moisture in the attic. Unfortunately, the combination of excessive moisture and heat can lead to mold.
Snow that melts from the roof of a warm attic, then refreezes at the gutters can cause what’s known as an ice dam. Ice dams can damage your roof. Snow on the roof should be allowed to melt naturally – which decreases the chances of runoff refreezing at the gutters.

Inhibiting your home’s natural air exchange through attic vents can trap harmful chemical and physical particulates. Ventilation helps keep the air fresh.

There’s a wealth of information on roof ventilation provided by Energy Star. And if you suspect your roof may be in need of repair or replacement, contact us for information and to schedule your free roof inspection!



  1. Daniel Arechiga on December 29, 2017 at 6:30 pm

    I live in an older single level home with single pane Windows,drafty doors and most likely uninsulated exterior walls. It gets freezing cold inside at night. I’ve cut out rigid foam insulation to fit inside the window frames to lessen the cold radiating from the Windows. I also trimmed around the door jams with weatherproof trim. I even nailed tarps around the exterior of an attached add on room that gets extremely cold at night. Despite all this it still gets cold in the house and I’m afraid to see what the heating bill is going to be. Any suggestions on what else I can do?

    • Brian Land on January 23, 2018 at 4:30 pm

      Hi Daniel!

      I am sorry to hear about your cold and drafty home. What you are experiencing is not uncommon. All of things you have done to remedy the problem are fantastic.

      I have a suggestion that I believe will help you even more and that is to blow addition insulation onto your attic floor. Since heat rises you are losing a lot of your warm air through your ceiling. Adding 18-24 inches of insulation will help keep the air where you need it to stay warm and cozy in your home.

  2. Mary Dyles on October 1, 2018 at 6:51 am

    i have an older style home that i recently had the roof replaced and the company installed a ridge vent in place of the whirly bird style i had. I have a lot of lint and dust particle in the home that i think is coming from the attic. wondering if the change in style is causing this disaster.

    • John Rampey on December 28, 2021 at 7:38 pm

      Check your dryer vent tube my be leaking.If your washing machine and dryer is inside you probably have bottom and a top vent take out vent screen and put a fiber filter on bottom and top then put vent screen back.In the attic there’s a big vent screen I put a AC filter over that to keep some dust out.I have a whirlybird on the roof to help with the heat all the electrical outlets I put caskets on them and sprayfoam a little on top of of electrical box where cord comes in to keep the draft out everything helps with air leaks

  3. Ron Benton on July 15, 2022 at 7:24 pm

    My wife had foam insulation installed and tge contractor insured on covering and stopping one of her two turbine vents is this common
    Her power bill was unusually high
    Could this be creating an extra strain on the ac unit in the end of tge house where tge turbine was closed off.

    • Lance on December 17, 2022 at 1:05 pm

      Absolutely. Don’t ever cover a properly installed turbine vent. It’s job is to equalize air temperature in attic space, to let warmer air out in the winter time to prevent snow from melting on your roof which is a bad thing, melting snow on your roof creates water, which can re- freeze if the outside temperature is below freezing, and cause ice dams at the eaves and hanging icicles, which could be dangerous to people and to your roof . Conversely in the summertime it lets out trapped heated air and moisture, which is also a bad thing, for obvious reasons.

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