Home>Discussions>INSULATION & HVAC>Attic Foam Insulation Options
4 posts / 0 new
Last post
Mathew
Attic Foam Insulation Options

Hi All,

I've ingested about every piece of information regarding foam insulation and my head hurts as there doesn't seem to be a clear answer. I had two companies come by and got two different options. One is an open cell 8" and another for 3" of closed cell. I live in Zone 5 (NY) to be exact and have duct work and an air handler located in the attic. The reason the one installer recommends open cell is due to locating a roof leak faster than closed cell foam. The closed cell installer claims its a superior product. What do you guys think? Especially those of you who live in my zone and had one of these types of systems installed? I'd greatly appreciate some real people input rather than those of sales people at this point.

keith3267
Re: Attic Foam Insulation Options

I live in a log home in a Zone 7, but open cell foam was used between the logs. Open cell foam holds water against the wood and water held against bare untreated wood, you can figure out the rest I'm sure.

Mathew
Re: Attic Foam Insulation Options

I thought open cell allowed water to pass through? Did you mean closed cell?

keith3267
Re: Attic Foam Insulation Options

No, I said what I meant. If i need to make this clearer for you, the installer that is recommending open cell foam because water passes through it is full of it. Have you ever used a sponge? Did you notice how long it stays wet after use?

If your roof leaks, you will have a problem no matter which foam you use. You can make a case either way. Open cell foam will soak up water and hold it for awhile so a small leak could go undetected for a longer period of time. Closed cell foam will cause the water to flow toward the soffits, if you are insulating the rafters and not the joists so it will be harder to find the leak, but it might be detected sooner.

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.