SUN CITY BLUFFTON HOME DEFECT CLAIMS posting 12/07
One of the installation concerns is the vapor barrier. Apparently, many of the home owners have reported mold issues and the vapor barriers have been in question. Normally expected installed under stucco plaster and on top of a wood substrate is two Grade D layers.
Invasive site discovery has identified single layering flashspun high-density polyethylene fiber material, which presented further discussion.
The TYVEK Facade Installation Instruct states: quote
Water-resistive barrier performance is dependent upon the ability of the façade to drain. You must consider the
following for specific façades.
When stucco is installed over wood-based sheathing the 2006 International Building Code (Section 2510.6) and the
2006 International Residential Code (Section R703.6.3) require “a water-resistive vapor-permeable barrier with a
performance at least equivalent to two layers of Grade D paper” or a layer of water-resistive barrier which is
separated from the stucco by an “intervening layer”. When two layers are required by code and DuPont™ Tyvek®
water-resistive barriers are used behind stucco they should be separated from the stucco by a second layer of
DuPont™ Tyvek® water-resistive barrier, a layer of Grade D building paper, felt, rigid foam board or the paper backing
of paper-backed lath. The first layer (directly over sheathing or studs) serves as the wall system’s water-resistive
barrier and is integrated with window and door flashings, the weep screed at the bottom of the wall and any
through-wall flashings or expansion joints. Lath shall be installed over the intervening layer in accordance with
ASTM C1063-03 Standard Specification for Installation of Lathing and Furring to Receive Interior and Exterior
Portland Cement-Based Plaster and applicable codes. Rigid foam board, when installed over DuPont™ Tyvek®
water-resistive barrier as an intervening layer, will provide enhanced structural support to the DuPont™ Tyvek® layer
and if installed within 24 hours of the DuPont™ Tyvek® layer may reduce the required number of fasteners used for
the attachment of the DuPont™ Tyvek® water-resistive barrier.
Rainwater Management Performance
Reasearch Report – 0503 2005 January by Joseph Listiburek