[Cob] Another inquiry on sealants...

[Bill Christensen]

At 2:06 PM -0700 11/3/10, Benjamin Brownell wrote:
>Not so concerned about breathability in this case

Breathability is not just important for living spaces.  One of the 
important values of having a breathable surface coating is that WHEN 
water gets in (not "if"), it has a way to get back out again.

The big trouble with many materials that are intended to make a 
monolithic "seal" is that eventually, they leak. When water/vapor 
gets behind that surface and can't get back out again quickly enough, 
then there's trouble - your earthen materials melt, your cellulosic 
materials rot.

All it takes is one little crack.

-- 
Bill Christensen
<http://greenbuilder.com/contact/>

Green Building Professionals Directory: <http://directory.greenbuilder.com>
Sustainable Building Calendar: <http://Calendar.SustainableSources.com>
Green Real Estate: <http://www.greenbuilder.com/realestate/>
Straw Bale Registry: <http://sbregistry.greenbuilder.com/>
Books/videos/software: <http://bookstore.greenbuilder.com/>