what is this foil insulation / barrier?

[CheckItOut]

I inspected a 1963 house today and the attic had foil like sheets that went between the rafters on the back of the roof and against the framing of the interior walls. Is this some sort of reflective insulation? I'm sure it is pretty much dysfunctional but any info would be appreciated.

[Chad Fabry]

Show me the foil.

It's likely a radiant barrier. Or, they knew for certain the government was trying to read their thoughts.

Les has a foil hat.

[hausdok]

The foil idea was very popular in the 50's and 60's. Too bad it doesn't work well when it gets dirt on it. It provides no insulative value whatsoever, but you couldn't have convinced anyone of that in the 50's and 60's. Come to think about it, there're some you can't convince of that now.

I've found lots of houses from that era that were built using only foil and no insulation. It's a good example of how manufacturers of building products will rush something into market as the next fad, before it's been fully tested or they understand how to use it properly. Lots of builders buy these new products and hastily incorporate them into their homes, thinking they are the latest thing, only to find out later that they don't work. Many have been bankrupted that way.

ONE TEAM - ONE FIGHT!!!

Mike

[CheckItOut]

Thanks. Yes, this one had no other form of insulation. Wonder if the house was built to grow a lot of weed?

On a similar note, my friend's sister stuffed foil in her light sockets so that aliens could not see her.

[AHI in AR]

Originally posted by CheckItOut

On a similar note, my friend's sister stuffed foil in her light sockets so that aliens could not see her.

Everyone knows it should go around your head for foil to work properly.

Duh!

[Brandon Chew]

Originally posted by hausdok

... It's a good example of how manufacturers of building products will rush something into market as the next fad, before it's been fully tested or they understand how to use it properly. Lots of builders buy these new products and hastily incorporate them into their homes, thinking they are the latest thing, only to find out later that they don't work. Many have been bankrupted that way.

ONE TEAM - ONE FIGHT!!!

Mike

Thread drift... That is what jumps into my mind when I see spray foam applied to the bottom of roof decking between the rafter bays in order to create a conditioned attic space. WHEN the roof covering or flashing leaks, where does the water go ... how will the homeowner be alerted to the fact that it is leaking ... and what kind of damage is it going to cause to the roof framing and sheathing before the leak is discovered?

[msteger]

I think the foil backed stuff is actually polystyrene? It is a radiant barrier like others above said. I've also seen it installed b/w drywall and studs, and foil tape is used at joints to continue the moisture barrier of the inner most foil layer.

[Tim Maxwell]

http://www.lpcorp.com/radiantbarrier/sa ... rrier.aspx

I saw this on a new construction this summer. It seemed like it was actually working because it was hot hot hot that day and the attic was not very hot, and it was in full sun.

[Jim Katen]

Originally posted by Brandon Chew

Thread drift... That is what jumps into my mind when I see spray foam applied to the bottom of roof decking between the rafter bays in order to create a conditioned attic space. WHEN the roof covering or flashing leaks, where does the water go ... how will the homeowner be alerted to the fact that it is leaking ... and what kind of damage is it going to cause to the roof framing and sheathing before the leak is discovered?

Well, if it's icynene, the water flows through the foam and drips on the ceiling below, just as it would with any other roof leak.

If it's urethane, the water just soaks into the framing and causes it to rot.

- Jim Katen, Oregon