Attic baffles play an important role keeping your home comfortable and safe. They keep space clear so fresh air can flow from the soffits under your roof eaves to the vents at or near the top of your roof, illustrated by the red arrow above.
Why Attic Baffles Are So Baffling
There are lots of names for attic baffles, enough to confuse anyone including those in the construction industry. My handyman technicians in New Hampshire called them proper vents. In Florida, when I asked what materials the proper vents were made of … I got a blank stare.
Researching the topic for this article explained the confusion. This simple building material has lots of names to describe the baffles that get inserted into attic rafters. Here are the names I found:
- Baffles – attic baffles, air baffles, insulation baffles, smart baffles and wind baffles.
- Vents – rafter vents, soffit vents, attic soffit vent baffles, proper vents or rafter vent baffles.
- Chutes – venting chutes, eave chutes and attic insulation air chutes
There are also references to baffles made from different materials. These include plywood attic baffles, cardboard attic baffles, cardboard insulation baffles, spray foam baffles, plastic or foam baffles, rigid foam boards and cardboard chutes.
When & Why You Need Attic Baffles
- Warm air in your home rises, ultimately reaching your attic.
- Warm air holds more moisture than cool air, so the moisture we create in our homes from bathing and cooking travels to the attic. Learn more at the Little Shop of Physics at Colorado State University.
- Reduce the impact of attic moisture that can damage the roof deck over time.
- Prevents wind washing and drifting of insulation.
Attic ventilation is more effective when you have blown in attic insulation and attic baffles. The baffles block insulation from covering up the soffit vents where it can reduce the flow of fresh air into the attic.
Which Baffles Should You Buy?
Installing attic baffles is messy and sweaty but it's not that difficult (view the video above to learn how). The biggest challenge is picking the right baffles for your home and climate. They come in standard widths so your decision needs to consider cost, depth from roof deck to avoid hitting roofing nails and type of material.
In fact the idea for this article came from my builder using cardboard baffles in Florida which I believe is wrong. Why? Cardboard will absorb moisture and Florida's average humidity is 75%. This means the cardboard will weaken over time and by holding moisture, there's the possibility of mold. So I started researching the cost of various baffles to see how much the builder saved using cardboard.
- Cardboard baffles – while not ideal, can save you money in locations like Arizona and Nevada, with low humidity. While I couldn't find cardboard attic baffles on Amazon, Home Depot or Lowes, you can buy them at JRProductsInc.com for less than $1.00/baffle.
- Styrofoam rafter vents – avoid the moisture concerns you have with cardboard. They look like egg cartons and have extra cones to keep the air vents open. You can buy various brands on Amazon (ADO shown below), Home Depot or Lowes, starting just under $2.00/panel.
- Plastic baffles – are stiffer and better able to withstand the pressure from insulation being blown into the attic, especially spray foam insulation (read: How Many Types of Insulation Are There?) These products start at roughly $2.50/panel and you can see a nice selection of baffles on Amazon.