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Stucco Part 3: Gavin Semrow has seen just about everything when it comes to stucco


The founder and CEO of Ai Restoration, Inc. in Pipersville said the restoration business shows no signs of slowing down. More and more homes are discovered to have failing exterior stucco applications due to poor or non-existing water, moisture and air management systems.

The 25-year industry veteran said when he began in the construction restoration business “we didn’t necessarily know or understand the real problem.”

Semrow said homes built before 1990 typically do not have exterior stucco failures because construction methods were different.

During the 1990s, many home building practices failed to take into account water, moisture and air management, and during those early years stucco took the brunt of the blame. Turns out, the stucco itself wasn’t the problem.

“The stucco wasn’t, and isn’t to blame. About 95% of stucco inspections don’t talk about the stucco being bad,” Semrow said.

The real issue with stucco failures is what is happening silently beneath the surface, or under the ‘skin.’

“As we moved along what we discovered was [materials] under the stucco or what was missing [to account for moisture conditions]. There has to be water, moisture and air management,” Semrow explained.

Because it is not possible to stop air, water or moisture from occurring between a stucco exterior and what it is built upon, functioning exterior home systems take the elements into account and manage them.

“The solution is truly air space,” he said.

Stucco isn’t alone. Brick, stone, and cement board siding are prone to the same underlying problems, Semrow said. “They all can leak, they all can hold moisture,” he explained.

Semrow said properly installed vinyl siding typically does not have the same issues as stucco because it “does an amazing job of controlling water, moisture and air.”

“It’s like a rain coat. It doesn’t hold moisture, and it has air space underneath it,” Semrow said.

Renovation or home restoration projects with failing stucco exterior systems must be evaluated from the ground to the roofline – and every nook, crack and cranny must be addressed to prevent future problems.

Semrow advised a licensed inspector is the best professional to fully evaluate problems.

Good maintenance is vital to keep a property without problems in good condition.

Moisture readings of a structure can provide a lot of information and help determine if closer evaluation should be done by a professional.

If a building shows no elevated moisture readings, and no rotted wood is discovered, regularly addressing these top maintenance best practices can help keep a stucco home sound for years to come.

• Watch “kick out” spaces, where a gutter meets a wall. These seams are vulnerable to leaking. Maintain seals and inspect problems if gaps occur.

• Calk every seam and gap. Look for lines where stucco meets vinyl windows as these seams can create a route for water to travel behind the stucco and materials behind it. Gaps between windows and stucco, or dissimilar surfaces, should always be calk sealed.

• Inspect exterior water spigots, windows and doors regularly. Every dissimilar surface needs to be calked along seams to ensure it is watertight.

• Address and seal seams around dryer vents, roof and soffit lines, decks and porches. Every component that touches the building from the ground to the roof line must be addressed.

Semrow does not recommend painting stucco because paint can trap moisture, and set the scene for future stucco problems.

“Clear sealing acts like a water repellent, like you might find on fabric. The sealant beads the water,” rather than absorbs it, he said.

Many homeowners aren’t proactive or even aware their homes may be rotting from the inside out, until they try to list a property for sale.

“For the homes we’re dealing with, there is a lot of pressure because they can’t even sell the stucco home. It can be devastating,” Semrow explained.

Any solution must involve water, moisture and air management systems.

Windows and doors must be removed and properly reinstalled so they are part of the new management system.

Failed stucco must be removed and any damaged materials, like rotted wood, must be replaced.

A new exterior system with a water, moisture and air management system incorporated into the new project design can then be installed, Semrow advised.

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