Under a Fine Surface, a Disturbing Discovery... ...and a Costly Repair
The owners of this one-year-old custom home . reported moldy smells behind the drywall; a mushroom growing from the cast-stone veneer face was the only visible sign of trouble on the exterior . The gutter butting into the top of the wall seemed a likely source of moisture, while the bottom of the wall provided no way for moisture to escape .
Opening the wall revealed severely rotted OSB sheathing and damage to the framing. While the row of soldier bricks at fascia height provided some protection , the water coming off the roof saturated the cast stone and soaked through the housewrap beneath, turning the sheathing at the base of the wall to compost in less than two years .
To repair the damage, the author's crew replaced the rotted wood members , but was able to leave the original drywall in place because it had been protected by the interior vapor barrier . Parts of the band joist were left in place but soaked with a copper-based wood preservative .

Destructive Investigation: Tracing a Leak to Its Source

On this job, the original installer of the cast-stone veneer wall had tried unsuccessfully to stop leaks by spraying a clear sealer onto the stone and by removing the lowest courses to apply a membrane flashing where the wall meets the foundation. To assess the problem, the Ram Builders team first seals large openings inside the home and sets up a blower door . With the blower door running to depressurize the house, the crew turns on a water-spray apparatus , thus simulating the effect of a 15-mph wind-driven rain. Within a short time, water finds its way into the house .After verifying that the cladding leaks, the team digs under the surface to find out why. Tearing off small areas of EIFS on the upper wall reveals that there is no building paper or window flashing installed where the EIFS meet the cast stone , or between upper and lower windows in the EIFS wall . Tearing off cast stone near a window , the team learns that water has wet the OSB sheathing. The author measures high moisture content even at the bottom of the wall, where no direct stream was applied . The retrofit flashing repair has proven ineffective because flaws higher in the wall dump water behind it.owns and operates Ram Builders, based in Lindon, Utah, which specializes in remediation and repair work in Utah, Texas, Colorado, and California.