Re: GBlist: Natural sealants

Hal Levin (
Mon, 24 Feb 1997 12:02:44 -0800

At 11:35 AM 2/24/97 PST, you wrote:
>A gasket option/question--
>Are polyethylene "backer rod" gaskets OK? They are available in diameters
>from 1/4" up to 2" for a few cents a foot from concrete and masonry
>suppliers. They are somewhat compressible and make good stuffers for larger
>cracks like windows to rough openings. They are intended as dams to prevent
>caulk sealants from sucking down into a wide gap before they can set up.
>When blower door testing houses, the backer rods look fairly tight even
>before caulk is applied over them.
Polyethylene should be reasonably stable and durable, especially absent any
direct solar radiation, and it will have minimal offgassing. Clearly not
natural, but what importance does "natural" have is a matter of dispute,
obviously. On the other hand, one certainly is not going to be able to lable
polyethylene "sustainable."

Hal Levin <>

This greenbuilding dialogue is sponsored by Oikos (
and Environmental Building News ( For instructions
send e-mail to