SB: RE: bales in ceiling was Bales in Floor

[jmark.vanscoter@amd.com]

I will totally agree with Aaron about the condensation potential with metal roofs. It is very real and can cause significant problems.

Again, I agree that bales used in a ceiling should be dipped in a clay slip or something similar. Otherwise, there is always a fire potential. However, I am not sure that a clay slip will help much to solve the water condensation problem. Even with complete ventilation (my circumstance was a shed that was open on one side), there was condensation on the roof that dripped one the floor. If there was a bale coated with clay in the path of the water drops, the bales would eagerly soak it up. Enough days like this and you get rot, mold, etc.

In my meager experience, the only safe way to use metal roofing is essentially use two roofs. the first is a roof of sheets of plywood, covered with roofing felt (aka tarpaper). Then build a grid on that roof layer so there is airflow between steel panels and the plywood subroof. Condensation will usually run off the edge of the panels and drip outside.

This has come up so many times that I finally prepared a PDF that illustrates one way of doing this.

Mark V.S. in Austin, TX

-----Original Message-----
From: Aaron Corbin [mailto:aaronc@frontiernet.net]

    One concern with metal roofs is that they condense moisture that can
drip onto the bales. I would deal with this by making sure the attic space
is well ventilated and the straw in the attic is covered in a clay slip. I
believe covering the straw in the attic with some kind of plaster is very
important and often gets over looked. Plastering provides a flame resistance
as well as increasing the R-value. As far as creating a vapor barrier on the
ceiling, I would think twice. Unlike fiberglass, straw has the ability to
let moisture migrate through it. I say let it move. If we vapor barrier the
ceiling that's all the more vapor that will be moving through the walls.
Aaron Corbin
Viroqua, WI

---------------------------------------------------------------------------
 > Well, if bales in the floor are not such a good idea, what about bales in
> the roof?  Obviously a vapor barrier is needed, but there are any other
> problems with putting bales under a metal roof?
>
> Steve


-------------------------------------------------------------------------
To unsubscribe from the list, send a message to:
   <strawbale-unsubscribe@crest.org>

or for the digest to:
   <strawbale-digest-unsubscribe@crest.org>

Please send any list administration questions to
strawbale-owner@crest.org