[Greenbuilding] Water Barrier

[Eli Talking]

I was not seeing the extent of liguid threat to building with siding 
blocking the wind driven liquid rain.  However, I have observed that when 
eps is exposed to prolong soaking such as in an exterior foundation 
insulation where poorly drained, it will hold water like a sponge.

Thanks for input.  Adding the building wrap is a pretty low cost way to 
decrease my risk.

Does any body see risk for multiple air (non vapor) barriers?  I understand 
the risk of trapping liquid between multiple vapor barriers.  However, my 
thinking is that just an air barriers will allow drying to the warm side 
even if one has leaks in the barrier.  Because so much of the performance 
for tightness hinges on the execution of the air barrier, I tend to want 
several layers of air barrier, such as sealing osb seams, sealing foam 
seams, taping foam seams, et.  Chances are all of those may have some 
execution flaws.  However, to leak all the way through they would need to 
line up with flaws on other layers.

Eli

-----Original Message----- 
From: John Straube
Sent: Saturday, March 02, 2013 6:16 PM
To: topher at greenfret.com ; Green Building
Subject: Re: [Greenbuilding] Water Barrier

Exactly.  And Tyvek is Gore-tex for buildings.

On 2013-03-01, at 10:46 AM, Corwyn <corwyn at midcoast.com> wrote:

> A water barrier is designed to keep *liquid* water on one side of it.  A 
> vapor barrier is designed to keep *gaseous* water on one side of it.
>
> Often a water barrier is purposefully made to NOT be a vapor barrier. The 
> common example is gore-tex clothing.  It keeps the rain out, but allows 
> the vapor of evaporated sweat from the occupant to escape.
>
>
> Thank You Kindly,
>
> Corwyn
>
> -- 
> Topher Belknap
> Green Fret Consulting
> Kermit didn't know the half of it...
> http://www.greenfret.com/
> topher at greenfret.com
> (207) 882-7652
>
> _______________________________________________
> Greenbuilding mailing list
> to Send a Message to the list, use the email address
> Greenbuilding at bioenergylists.org
>
> to UNSUBSCRIBE or Change your List Settings use the web page
> http://lists.bioenergylists.org/mailman/listinfo/greenbuilding_lists.bioenergylists.org

John Straube
www.JohnStraube.com


_______________________________________________
Greenbuilding mailing list
to Send a Message to the list, use the email address
Greenbuilding at bioenergylists.org

to UNSUBSCRIBE or Change your List Settings use the web page
http://lists.bioenergylists.org/mailman/listinfo/greenbuilding_lists.bioenergylists.org