Re: Condensation in SB Walls

[SwKohl@aol.com]

         I was watching the show Hometime earlier in the fall.  I saw  a
contracor spraying some kind of rubberized coating on a wall that was going
to be below grade.  I was thinking that maybe you could spray a straw bale
structure the same way.  You would build the structure and spray the outside
of all bale walls.  Then, you would apply the stucco mesh.  The mesh would
solve any incompatabilty problems between the plaster and coating. 
         On our panel houses, we use 14 gauge 2 x 2 welded mesh.  The only
disadvantage to it is that you have to use a pump to apply the scratch coat
since the squares are so big.  There is a 16 gauge 2 x 2 mesh that is
available with a paper backing.  It is called GunLath.  The paper keeps the
plaster from blowing through the wire.  It is used a lot with open 2 x 4
construction.  This mesh is also available with a waterproof building paper.
 It is used for stucco work for any areas where moisture is encountered. It
is called Stucco Rite or Aqua-K-Lath.  This might help alleviate some of
 your moisture problems.  This kind of lath would be ideal to use with a weep
screed that I have been talking about.  Here is a excerpt from a book on
plastering skills.
         " Metal lathing for exterior work follows the basic pattern followed
in interior work, but there are some important differences.  One, all
surfaces to be lathed should be covered with waterproof building paper or
plastic.  Two, the lath should be of a heavier gauge and with large openings
or meshes.  Three, the lath must be applied in such a manner that it is not
in direct contact with the background or base.  Recomended practice is to use
fastners with a furring device that holds the lath out 1/4" to 3/8 " from the
framing ( or strawbale ).     One of the most important factors in good
exterior plastering is the use of the correct flashings, drips, expansion
joints, and stops.  Unless the exterior material is protected from water
seepage behind it, there will be trouble in short time. "        Plastering
Skills, F. Van Den Branden, American Technical Publishers, pg 200 + 201.
                                                Steve W. Kohl
                                                SwKohl@aol.com