by Jerry Peck - Codeman on Sun Apr 05, 2009 8:00 pm
Hi Richard,
You are referring to stucco on frame, right?
If there is a control joint leaking as you describe where moisture/water is getting inside the wall past the WRB, then the problem is bigger than what you are thinking, the problem is that *something* ... or *everything* ... was done incorrectly on that installation.
That would be the wrong code reference, you would need to refer to the stucco section and ASTM C-926 and ASTM C-1063 for that problem.
Without destructive testing there is no way to know for sure what was done, not done, or done incorrectly, or which of the above to apply, so applying all sections will cover it.
From the 2004 Florida Building Code, Residential with 2006 Revisions. (underling and bold are mine)
- R703.6 Exterior plaster.
- - R703.6.1
- - - Exterior use of portland cement plaster shall comply with the application requirements of ASTM C 926.
- - R703.6.2
- - - Installation of exterior lathing and framing shall comply with the application requirements of ASTM C 1063.
- - R703.6.3
- - - Where cement plaster (stucco) is to be applied to lath over frame construction, measures shall be taken to prevent bonding between the cement plaster and the water-resistive barrier. A bond break shall be provided between the water-resistive barrier and the cement plaster (stucco) consisting of one of the following:
- - - - 1. Two layers of an approved water-resistant barrier material; or
- - - - 2. One layer of an approved water-resistant barrier over an approved plastic house wrap; or
- - - - 3. Other approved methods or materials applied in accordance with the manufacturer’s installation instructions.
- - R703.6.4 Pneumatically placed portland cement plaster.
- - - R703.6.4.1
- - - - Pneumatically placed portland cement plaster shall be a mixture of portland cement and aggregate conveyed by air through a pipe or flexible tube, and deposited by air pressure in its final position.
- - - R703.6.4.2
- - - - Rebound material may be screened and reused as aggregate in an amount not greater than 25 percent of the total sand in any batch.
- - - R703.6.4.3
- - - - Pneumatically placed portland cement plaster shall consist of a mixture of one part cement to not more than five parts of aggregate. Plasticity agents may be used as specified elsewhere in this chapter. Except when applied to concrete or masonry, such plaster shall be applied in not less than two coats to a minimum total thickness of 7/8 inch (22.2 mm).
Jerry Peck - CodeMan
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Construction Litigation Consultant - Retired
Construction and Code Consultant - Semi Retired