MyFloridaCode.com

Jack, the situation you have encountered is all too familiar with many
of us.  The question however is complicated in its scope.

First, the water intrusion problem the owner is experiencing relates to
violations of the code concerning interstitial water intrusion - rather
than improper stucco application and I believe the owner should seek
primary recourse along that path (secondary recourse is the stucco and
waterproofing issues).

As to your question, I have been in many court cases where this issue
has been litigated, and there are no exact answers.  Yes, if stucco is
applied according to the Florida building code then it must meet the
requirements of ASTM C-926. But what if the stucco is not being applied
pursuant to code requirements, i.e., it is simply being applied as a
decoration? Herein lies the problem.

If stucco is a being applied for fire resistance value, or is being used
for its shear value, or is being applied over "open" framing members,
then it must meet that requirement.  If it is not used for any of these
purposes - then it falls outside of the code requirements. It is
decoration. (read the 553 mandate for the code and the purpose of the
code)

Consider the requirements over masonry block.  The code requirement
would mandate a minimum of 1/2" thickness.  Blocks however need
absolutely no stucco requirement in order to attain C/O. Then why 1/2"
thick?  Absence the requirement for additional wall shear, or fire
resistance value there is no reason for such thickness.  Therefore the
code defined a "decorative cementitious coating" to eliminate this
requirement since it was being applied by people in the field who failed
to understand that the ASTM documents are not Florida specific. They are
meant to be read by technical trades who interpret them.

Likewise goes the argument for a fully structurally sheathed frame wall
in Florida.  You could simply paint a plywood exterior sheathed wall,
and receive the certificate of occupancy.  All shear value, fire value,
and water resistant value being attained without any other product
(other than the required coating or stain for waterproof integrity). At
this point all code requirements have been met. So what if the owner did
not like painted plywood, or painted OSB?  We could simply nail some
vinyl siding over a waterproof underlayment and pass inspection.  Or we
could simply trowel some stucco for cosmetics over the plywood.  But of
course, stucco does not stick to plywood and it is not watertight.
Therefore we need an effective water management barrier and metal lath
to serve as a mechanical "key" to hold the stucco on.  At this point it
matters not (with this specific wall framing condition) the thickness of
the stucco.  By the nature of its installation it will be approximately
half an inch thick.  So if a product is being applied for cosmetics, and
not subject to the requirements of the code, does it need to follow the
code reference document?  The argument continues.

What is a fact is that either an effective water management system such
as 15 pound felt, stucco wrap, peel and stick must be used under the
stucco, and a means of letting the water drain out once the water
management system carries it down to its termination (this is what is
missing in your application, along with I am sure insufficient or
nonexistent window flashing) or the other option of a face barrier
system.  This system prevents any water from getting behind the stucco.
Obviously this is a far more complex system and must employ correct
coating materials as well as correct sealants. Any windows will probably
need to be pulled and reset with a proper pan. 

There are thousands and thousands of houses in Florida that perform
perfectly well with stucco over these fully sheathed frame walls.  Most
were painted to the correct mil thickness by painters with rollers and
brushes (not airless sprayers) and many have been painted several times.
Either way there is a quasi face barrier system created. These houses
have performed without the weep screed's or expansion joints.
Nonetheless your house is not quite one and not quite the other.

(note; I am not against air-less sprayers used by a competent painter.
The fact remains however, that if you test many new homes in the field,
it is not un-common to find 1/2 to 2/3 of the required mill thickness
missing)

As for expansion joints, they are required by the ASTM documents,
"unless otherwise specified".  We always make sure to specify them out.
They cause far more harm than good and if you think about it cannot
provide any expansion mechanism when the metal lath is nailed 7 inches
vertically - 16 inches horizontally on center. The available panel for
expansion could not exceed 16 inches in width.

What we need to do in our Florida environment is mandate the requirement
of peel and stick on all residential exterior wall and roof areas that
have wood sheathing that is to be covered with any other material.

IMHO,

R.J.Koning - Director
Contractors Institute
rjkoning at contractorsinstitute.com
8301 Joliet Street
Hudson, Fl 34667
727-863-5147



-----Original Message-----
From: codetalk-bounces at myfloridacode.com
[mailto:codetalk-bounces at myfloridacode.com] On Behalf Of Jack Wingo
Sent: Friday, September 19, 2008 4:20 PM
To: codetalk
Subject: [Florida Code Talk] Cementitious Finish

Hello To All,
A 2 story house built in 2002 after the 2001 FBC became effective.  
First floor walls are poured concrete and second floor walls are frame 
with OSB sub-siding, Tyvek, wire lath with an under coating of what 
appears to be 1 or 2 coats of plaster.  Both 1st and 2nd floor walls 
have what appears to be a stucco finish, that was painted.  The 2nd 
floor walls have no expansion joints and no weep screed.  The homeowners

have complainted to the builder about water intrusion from wind driven 
rains.  After tropical storm Fay, stalled in our area for several day, 
while dumping several inches of rain, the homeowner removed some 
sections of drywall on the 2nd floor exterior walls.  There is extension

water damage to the sub-siding and damage to some wall studs. 
During a meeting with the builder and the homeowner, I handed the 
builder a copy of code 2504.2 Exterior Lathing and Plastering, a copy of

ASTM C 926 and ASTM C 1063, and some pages from the Portland Cement 
Association's "Plaster/Stucco Manuel".  The builder stated he was not 
obligated to the ASTM requirements because he applied a decorative 
cementitious finish in lieu of stucco.  I ask for the name of 
manufacturer, but he refused to provide that information.  He simply 
stated he was not require to install expansion joints and weep screed, 
although he is now on homes he is presently building. 
My questions include, what or who determines if a product is stucco or 
decorative cementitious finish and no matter what the exterior finish 
may be, wouldn't the requirements of expansion joints and weep creed, 
still be required?
Your assistance will be greatly appreciated.
Jack Wingo
Melbourne Beach, FL
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