Stucco Repair: How to Properly Repair Stucco

Stucco Repair Philadelphia may sound like a daunting task, but it’s actually more manageable than many homeowners think. With a few tools and the right preparation work, you can patch small cracks in stucco walls.Stucco Repair

Before you start, remove any damaged stucco and debris. Examine the metal lath and tin snips uncovered to see if they need replacement.

Stucco is porous by nature and can absorb moisture easily. However, it should not be holding moisture underneath the surface, where it can cause rot and mold issues.

A symptom of this problem is dark spots or streaks in your stucco. These are areas where the underlying plaster has become discolored due to prolonged exposure to water and sunlight. In addition to this cosmetic concern, dark spots can also indicate that the underlying drywall has become soaked and is weakening.

If you find this issue, it is likely that a simple patch job will not be sufficient to fix the problem. Instead, you may need to perform a full remediation of the wall system to solve the underlying problems.

This is a more extensive process than repair and is generally only performed when there is evidence of a larger problem with the stucco system. This could be due to poor stucco installation or that the stucco is simply old and no longer holds up well.

Stucco remediation involves a complete replastering of your entire stucco wall system to address the underlying problems. This is a much more involved process than repair and requires a team of more highly skilled workers to perform it correctly.

The most important reason to opt for stucco remediation is that it is a permanent solution to the underlying problem. Once the stucco is completely replastered, it will no longer be susceptible to moisture penetration.

One way to see if your stucco needs to be remediated is by checking the condition of the caulking around the windows. If the caulking is dry, cracked, or missing, this is a sign that moisture has been entering your home through the stucco and damaging the underlying drywall.

Another way to check for a deeper moisture problem is to have a professional conduct exterior probe testing on your stucco. This involves drilling a small hole into your stucco and inserting a moisture meter, which will give you direct readings of the moisture levels within your walls. High moisture levels can lead to staining, efflorescence, and blistering, all of which require a full remediation of your stucco.

Water Leaks

Water leaks can be a serious problem for stucco homes. If left unchecked, the resulting damage can lead to crumbling and even structural failure. This is primarily caused by poor construction or sealing around windows and other details, which allow moisture to seep in and trap it inside the stucco. The first sign of this is often a musty smell that appears to be coming from the stucco. Other signs include sagging of the stucco or plaster, cracking, and a general discoloration of the wall.

Water intrusion into stucco can also result in a loss of adhesion between the plaster coats or from the substrate, which can eventually lead to bulging and collapse. This is especially dangerous where the stucco meets another structure, such as a window frame or roof, where there is a potential for a gap to develop. This type of damage is usually the result of poor flashing and sealant, which may be due to a number of factors, including the age of the home or inexperienced contractors.

If the problem is caught early, water leaks in stucco can be repaired relatively inexpensively. However, if you ignore the warning signs and let the water damage continue, the costs can escalate rapidly. The best way to determine if there is a problem is to perform some water testing. Start with the area above a window where the water is most prevalent and mask off the windows, then run a steady stream of water from a hose for 20 minutes, paying particular attention to flood the areas where there are cracks. After the test is complete, observe the interior of the building to check for moisture infiltration.

Other signs of problems are stains on the stucco that can’t be easily wiped or power-washed away. These stains can indicate that there is a much deeper issue that needs to be addressed.

A good rule of thumb is to examine the exterior of a stucco home once every season for any of these issues. If you do spot any problems, be sure to contact a stucco repair expert right away.

Loose Lath

If stucco is sagging or loose on a wall, the problem is caused by lath that has not been properly installed and covered. Loose lath may allow water infiltration, which leads to cracking and delaminates the stucco from the wood or metal lath supports. The problem can be corrected by installing new lath and covering it with three coats of stucco mix.

First, chip away any loose stucco until you reach the layer where it firmly adheres to the lath. Then, cover the area with grade D building paper to create a moisture barrier. Then, nail or staple water-resistant sheathing felt to the paper and furrow strips over it. Finally, nail or screw galvanized metal lath to the furring strips and then apply a new layer of stucco.

Stucco can crack in many ways, including improper mixing of the mortar, poor installation, and a variety of other factors. If you find hairline cracks in the stucco, seal them with exterior latex paintable caulk in a color that matches the stucco. This type of caulk will bridge the cracks and prevent moisture infiltration.

Before you patch a hole in your stucco, make sure the wall is dry. If it isn’t, you should apply a vapor barrier coating to the wall, which will prevent moisture buildup and keep it from evaporating into the air.

You can repair a small hole in the stucco by using a pre-mixed stucco patch kit. The most important step is to follow the manufacturer’s instructions carefully. Then, trowel the patch into place and let it set for the recommended time.

The final step in making a successful stucco repair is to add a pigmented coating to the patch to match the surrounding stucco. The best choice is a sprayed-on acrylic elastomer, which can be tinted in the store to match the color of the stucco. Other acceptable coatings include concrete paints and stains, mineral paints, or lime washes.

Before you start working, determine whether the stucco on your house is made of lime or Portland cement. To do this, use muriatic acid on a sample piece of stucco. The acid should dissolve the lime but not the Portland cement. If the acid dissolves the Portland cement, then you need to use a different stucco mix on the repairs.


Mold can be a serious issue for stucco owners. Molds need moisture to thrive and often grow on or under the stucco surface. If this isn’t dealt with, it can lead to further problems with the structure of the home. The best way to deal with mold is to prevent it from growing in the first place. This is done by properly sealing the exterior of your home and keeping it clean.

Stucco needs to be washed regularly to keep it free of dirt and debris. This helps to prevent the buildup of organic material that provides a food source for molds. Stucco also requires a good water-resistant seal to help prevent the ingress of moisture into and behind the walls. This is especially important for homes in wet climates where mold can thrive.

Water intrusion into stucco is often caused by the lack of a drainage plane or weep screed. This causes the moisture to remain trapped in the wall cavities, which can cause mold and rot. The problem can be exacerbated if the wrong materials are used in a repair and installation project. For example, the use of hard cementitious materials incompatible with stucco can exacerbate decay instead of slowing it down or preventing it.

If a house is flooded or has experienced a significant amount of rain, it’s a good idea to call in a professional to check out the stucco to see if any damage was caused. If not addressed promptly, this can lead to severe structural damage that is not covered by homeowners’ insurance.

Stucco and EIFS need to be cleaned frequently as they are susceptible to stains. Stains can be caused by many different things, including a buildup of algae, oil, and other pollutants in the air. It is best to use a pressure washer to remove stains. Start with low pressure and work up as needed. It’s also a good idea to use a brush attachment to scrub away stubborn stains. A mixture of water and regular dish soap or oxygen bleach works well for cleaning the stucco.