Construction Products That Don’t Work: Foam, Cardboard or Other Cheap Attic Baffles

by Cody Farmer

Do you have good baffles? Mainstream reviews hundreds of plan sets every year and I rarely ever see an attic baffle drawn or even talked about in detail. Back in 2011 when we were building Passivista we were greeted with this problem face-to-face because we had to determine how to seal in between the raised-heal trusses. It’s been a while now and I can say I've seen a handful of solutions finally come to the marketplace and I think we’ll consider using them in our specifications.  


First, let's look at why the existing baffles are a joke. Besides the air space being too small, the foam structure has impedances that restrict air. They neglect the truss spacing and when attic insulation fill is happening many inevitably take some on and that further restricts air movement. Foam also shrinks and warps with time which means it eventually will not be covering the area you intended to cover. Cardboard baffles encounter the same problem because they tend to curl with age – again, not covering the area you originally intended. If you're looking for optimal attic ventilation while employing airtight construction in Colorado (or anywhere, for that matter), these materials are not ideal. Any kind of green construction in Colorado requires a better solution.

The industry treats the attic space as if no one will ever be up there. However people end up in attics several times a year sometimes installing extra wiring, antennas, venting pipes, repairing roofing.. you see what I'm saying. Thus anything serviceable should be made for a long-term lifecycle, a Passive House value.  The big insulation companies and others offer a flexible thin foamy baffle or cardboard or other chintzy material to do a heavy duty job. These are not good choices for an important task in my opinion. So the typical attic is full of cheap, delicate, fragile, restrictive and easy to fill up with insulation baffles to keep your attic dry.

We feel the industry should look at a better solution like this: 


Certainly, an equally important issue is: how does your ceiling air barrier fit under the attic baffle?  Do you have a ceiling air barrier? Are there can lights weaving in and out of it? Oy vey!! Let’s talk about ceiling LED lighting and Defective Products and efforts next “Rog” or “ranting blog”.

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