The word "efflorescence" may sound pleasant to the ear – something like flowers or light. But in fact, when it comes to stucco, efflorescence can be a serious problem, turning an attractive and durable building material into a disaster waiting to happen.

Stucco is very moisture-sensitive; well-built and properly maintained stucco can hold up for a lifetime, but stucco that is exposed to interior moisture can break down from the inside over the course of a few years. Efflorescence is a sign that stucco is not properly protected against the elements – and that means moisture is getting into your stucco.

What Is Efflorescence?

Efflorescence is a whitish, crystalline material that you may find on the surface of stucco (as well as some other materials, like concrete). The crystals are actually salts that have been carried from behind the stucco, out of the base material, and ended up on the surface of the stucco. It can be removed by scrubbing with water or by applying various acids, but this solution is usually temporary.

What Does It Have To Do With Moisture?

Stucco buildings are actually comprised of a base covered with stucco, which is similar to plaster – it is applied wet to the base material and allowed to dry. The efflorescence comes from the base material, occurring when the material gets wet, dissolving salts inside it. The moisture within the wall then makes its way to the surface, through the stucco, and evaporates, leaving the salts behind.

Why Is Moisture So Bad For Stucco?

The stucco itself may not show many signs of moisture damage, which is why looking for efflorescence is important. What is damaged, however, is the interior of the walls. Moisture that gets into the walls becomes trapped there, with usually only a portion of it managing to seep out through the stucco. The moisture within the walls leads to rotting wood framing, mold, mildew, and even structural collapse in severe cases.

What If You Have Synthetic Stucco?

Buildings made of both traditional and synthetic stucco can suffer from efflorescence. Both are usually applied over a similar base layer, and they both can trap water within walls if they are improperly sealed or compromised.

What Should You Do Now?

Efflorescence is just a symptom of a deeper problem – so while you can certainly clean it off yourself, it's important that you call a contractor to examine your stucco as soon as possible. Somewhere, whether through improperly sealed trim, cracks in the stucco, or failing sealant, there is moisture getting in. What will need to be repaired will depend on just where the moisture is coming from, so a thorough inspection is key.

For more help with stucco repair, contact a company like Advanced Wall Systems Inc.

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