Does stucco let water in?

Despite what many people think about stucco walls, stucco walls are not water-resistant. As a matter of fact water actually absorbs into the stucco. In most cases, the problem with water leaking through stucco is that the building envelope has been breached.

How does water get into stucco?

During heavy wind driven rain the water will absorb through the stucco layers quickly and you will notice after rain storms that the weather sides of the house will take hours and sometimes even days to completely dry out (see picture of south exposure after rain).

Does stucco stop water?

Since stucco is a masonry product, it is often believed to be waterproof already. However, this isn't totally true — stucco is indeed permeable and will let some water through.

Is stucco a watertight?

With so many people who own stucco homes struggling with wall rot, there has been a renewed interest in the subject of waterproofing stucco. Stucco itself is fairly waterproof on its own, but stucco walls and openings in those walls need to be correctly installed in order to achieve true waterproofing.

Does stucco need sealing?

Sealing your stucco is a great way to prevent water absorption. New stucco should be sealed with a clear concrete masonry sealer, typically made of a silicone material. For older stucco that's already showing signs of cracking, waterproof elastomeric paints are an excellent choice to preserve and protect your stucco.

Identifying Water Intrusion Through Stucco

What is the main problem with stucco?

There are several stucco problems that you can encounter. The most common ones are staining and discoloration, stucco cracking, and moisture intrusion. Other problems include stucco extending below grade and caulking. Some of these issues will need either repair or remediation.

How often should stucco be sealed?

If new, stucco can be sealed with a clear concrete/ masonry sealer, which will penetrate into the stucco and stop moisture entrance. These are typically silicone type sealers. While effective, these finishes will usually need to be redone every 4-5 years.

Does stucco need weep holes?

Weep screeds are generally only used on walls constructed with wood framing, and are not required on stucco-coated masonry structures or when adhered stone is installed over masonry.

How do you fix moisture in stucco?

If you believe the stucco requires a minor repair, you can remove the damaged section of stucco, much like you would with damaged drywall or rotted wood. Patch the area with a stucco mix that matches your current exterior. Apply three coats of the stucco and allow for drying time between applications.

What goes behind stucco walls?

Sheathing is basically the “backing material” that can be found underneath the various layers of stucco that form the backing of residential and commercial buildings. They can be made out of wood, cement, gypsum, fiberglass and other materials.

What do you put behind stucco?

Because stucco is porous, the base—typically plywood or oriented-strand board sheathing—must have at least one layer of weather-resistant, vapor-permeable asphalt-impregnated building paper (“felt”) or plastic-based building wraps or stucco wraps.

How long does it take for exterior stucco to dry?

In a traditional three-coat stucco system, the finish coat must be cured using the same practices as base coats. Moist-curing can be terminated after 48 to 72 hours, but the finish coat should remain uncoated for at least seven days to prevent coating failure or poor bonding.

Why you should not paint stucco?

Stucco needs to breath – One of the main reasons you shouldn't coat your stucco with paint is because stucco is porous. This allows moisture that hits the surface to easily evaporate away. A coat of paint can harm that breathability.

Can you use a pressure washer on stucco?

Yes, you can use a power washer or pressure washer to clean stucco. Just make sure to maintain a good distance between the nozzle and the surface, use the 1,500 PSI, and a 25- or 40-degree nozzle. Although, given the intensity of a power washer, seeking the help of a professional is always best.

Does stucco last forever?

Stucco is a very durable finish material with a typical life span of 50-80 years or more. Although it is one of the most durable surfaces available, it also features the lowest annual maintenance cost when compared to other siding materials. Stucco is a natural material consisting of an aggregate, a binder, and water.

Why do builders use stucco?

2. Durability – the biggest advantage of Stucco is that it is resistant to fire, rot, mold, impact, and termite infestation. The finish on stucco homes has the capability to last up to 100 years depending on local climate conditions.

Is stucco good for a house?

Stucco is a cement, sand, and water mixture, so it stays rigid, even in strong winds. Many folks may even prefer buying a stucco home over, for example, a brick structure. Additionally, stucco is fire- and pest-resistant, making it one of the most ideal residential building materials.

Is it safe to buy a stucco house?

Stucco can tolerate moisture and expansion only up to a certain point. It is not as good as brick veneer or vinyl siding for keeping water out of the exterior walls of your house during periods of heavy rain. It will repel water well in average climates, but it may not be recommended in extremely rainy areas.

How often should you paint exterior stucco?

Stucco is a popular exterior choice due to its durability. However, a stucco home will still need exterior maintenance. It is often recommended that stucco be painted every 5-10 years depending on its current condition.

Can You Use Flex seal on stucco?

A: You can use Flex Paste on a wide variety of surfaces such as wood, glass, tile, concrete, aluminum, metal, brick, stucco, masonry, copper, fabric, fiberglass, ceramic, porcelain, natural stones, roofing, PVC, EIFS, EPDM, CSPE, Hypalon polyurethanes and so much more.

Does stucco stick to concrete?

ASTM Standard C 926, Specification for Application of Portland Cement-Based Plaster, permits direct application of stucco to solid surfaces like concrete and masonry as long as bond is sufficient. Concrete masonry surfaces are both absorbent and textured, two things necessary for bond.

Should I waterproof My stucco?

Waterproofing is essential for almost every building project. If not properly sealed, structures will allow moisture to seep into materials, where it can become trapped. If this moisture does not drain properly, it can cause rotting, damage and mold. With this in mind, it's important to properly waterproof stucco.

Can you leave stucco unpainted?

The short answer is... yes, stucco can be left unpainted for a short period of time or forever! Most stucco systems (not EIFS) use cement based products in their base coats and in some cases in the finish coat too (traditional finishes) which are proven to last long periods of time.