How to Repair Stucco Siding
Stucco is a very strong, durable cement-like siding material but repairs are sometimes needed for cracks and holes.
Though you’re better off leaving major stucco repairs to a mason or stucco specialist, you should be able to handle fixing most holes and cracks if you have do-it-yourself experience. The way you make these repairs will depend upon the nature of the damage, such as the size of the hole. Here we look at typical stucco repairs. For information on painting stucco, please see How to Paint Stucco.
Fixing Large Holes in Stucco
Patching large holes in stucco is a job that homeowners adept at basic home repairs can handle-though it may be difficult to create a patch that blends perfectly with the wall unless you repaint. If you are not comfortable doing this type of repair, contact a local siding contractor.
If you decide to do the job yourself:
- Remove loose stucco from the hole with a cold chisel and ballpeen hammer as shown at right; blow out the dust. Staple new wire mesh over any damaged mesh. Spray with water.
- Apply the first coat of stucco to within 1/4 inch of the surface, using a mason’s trowel or putty knife (stucco should ooze from behind the mesh). When firm, scratch with a nail. Let cure for two days.
- Apply the second coat over the dampened first coat to within 1/8 inch of the surface, using a mason’s trowel or putty knife, as shown below left. Smooth the stucco and let it cure for two days.
- over the dampened second coat with a metal float or mason’s trowel. Smooth flush with the existing surface. Texture as desired, and allow to cure for four days.
- Paint if necessary.
HomeTips Pro Tip: For deep holes, build up the patch with several successive layers, allowing each to dry before applying the next. Match the texture by touching it up with a float or a small brush.
Fixing Small Holes in Stucco
Here is how to repair a small hole (less than 6 inches wide):
- Use a stiff brush to clean out the hole. If the hole is too small for a brush, use an awl or nailset to scrape out any loose material. Then blow out the dust (wear eye protection).
- Apply a new patch of stucco patching compound, using a putty knife. Pack it tightly into the hole and fill almost to the surface. Allow this patch to set up until it is stiff.
- Apply a top coat of patching compound. Use the putty knife to blend the surface of the patch so that it matches the wall. Then allow this coat to dry.
The Difference Between Stucco Repair and Stucco Remediation
In the home repair industry, stucco repair and stucco remediation are two very different services.
Repairing faulty stucco siding is not at the top of anyone’s home improvement wish-list, but inaction is not a good option when it comes to moisture intrusion. As you begin to research your stucco repair options, the vocabulary of the industry can be confusing. Be sure you understand the difference between stucco repair and stucco remediation so you can discuss possible solutions with your siding contractor. In some circumstances, stucco repairs (such as re-sealing the stucco around windows, flashing and joints) may be enough to remedy stucco failures. However, when water has been penetrating the stucco over a long period of time, a full remediation may be necessary.
What is Stucco Repair?
Stucco repair refers to the practice of finding specific instances of stucco failure, fixing those specific problems, and then replacing the damaged material with more stucco. In a nutshell, stucco repair means you fix the damage, but not the underlying defect. This is similar to treating symptoms of illness rather than curing the disease. As a less-invasive option, stucco repair may miss water damage in some areas of your home where the stucco was not removed.
What is Stucco Remediation?
The word “remediation” means “the act or process of correcting a fault or deficiency.”
As opposed to stucco repair, stucco remediation means fixing the underlying defect in the stucco construction. This process most often involves replacing your home’s entire stucco system in order to fix the root cause of the damage: a faulty installation. Stucco remediation fixes underlying defects rather than only addressing the cosmetic or functional symptoms, meaning you will not have to remediate your home twice – Especially if you replace your stucco with a better siding product, such as James Hardie Fiber Cement Siding.
When Do We Use Stucco?
Traditional stucco was used primarily as an aesthetic yet durable and water-resistant wall covering. It can also be used for chimneys, and architectural and sculptural additions. In some parts of the United States, especially Florida, stucco is predominantly an exterior feature in both residential and commercial construction.
How do We Apply Stucco?
Although initially applied to bare materials, it wasn’t long before a wooden lattice network, or “lath”, was introduced as the base layer to supply support to wet stucco as well as tensile strength to cured stucco. Now, modern Portland cement stucco is applied to a metal lattice or “mesh”. The mesh itself is tightly secured to the surface with nails or screws.
Stucco was applied in three layers: the scratch coat, leveling coat, and the finish coat.
The scratch coat can be applied by hand or by machine but its surface layer must have horizontal or criss-cross pattern troweled into it for added stability of the next layer. The first layer is allowed to fully cure before the second is added. The leveling coat is quite thick and with the help of many tools, is used to level out the layer of stucco to provide a smooth surface for the finish coat. This second layer should be given 7-10 days to fully cure. The finish coat carries all the aesthetic value and can be troweled smooth, hand-textured, sculpted, or sprayed – with or without added pigments.
Stucco repair project overview
- Difficulty: Easy
- Timing: Less than an hour per patch
- Warnings: Wear gloves and eye protection when mixing or chipping
Equipment you’ll need
- Work gloves
- Eye protection
- Mason’s chisel
- Premixed stucco or a patching compound
- Notched trowel
- Plaster finishing trowel
- “Finishing” tool (e.g., whisk, sponge, piece of board)
Step 1: How to make DIY stucco
Stucco changes color over the years, so your new patch probably won’t match. But you can the new layer after installing, or buy coloring pigment to add to your mix to match the existing color. Mix small batches, add some pigment to the mix, then put it on a piece of cardboard, and allow it to dry. You will need to try different amounts of pigment until you match the color, and you will want to do it before you start your repair.
Step 2: Apply the first coat
Use a mason’s chisel and hammer to chip away any old stucco or loose material. Then use a finishing trowel to paint on the damaged area and repair cracks. This first layer is called the “scratch coat” (you’ll see why next).
Step 3: Add grooves
When the scratch coat is applied, use the notched trowel to scratch grooves into the mud. This helps future coats adhere better.
Step 4: Prepare for the brown coat
After the scratch coat sets and dries for at least 24 hours, sponge water onto the area to help the next coat adhere. This next layer is called the “brown coat” regardless of color.
Step 5: Apply the coat
Make sure you spread this layer of new stucco evenly, then “screed” (leveling with a straight edge) the mix to ensure the coat is flat and level (no texture)
Step 6: Apply the final coat
Make sure this final coat is a quarter-inch think and evenly applied.
Step 7: Texturize
For the final repair step, use a sponge to create the outer texture. If you didn’t add pigment at the beginning, paint the surface now. You may have to paint the entire side to disguise the patch.
Are Small Cracks in Stucco Normal?
Many people put years of hard work into their home to make it as comfortable and safe as possible! Stucco home owners are no different. Oftentimes, house hunters specifically invest in stucco homes because they know that stucco has a great reputation. So when you put lots of time, money and effort into your stucco home, seeing a crack on the surface can be frustrating. The first question you ask yourself might be, ‘are cracks in stucco normal?
Now that you know small cracks in stucco are normal, let’s find out a little more about why it happens:
- Extreme weather – If your stucco has been recently applied, it can be vulnerable to heavy winds and rain. Too much wind can suck the moisture out of your stucco, causing it to shrink and crack, while extreme heat and rain over time can cause the stucco to deteriorate.
- Nearby construction – Construction sites down the road, loud explosions and even a close flying plane can cause your home to shake which may give way to stucco cracks.
House settling – If you live in an older home, or a home built on loose soil, the pressure of your home sinking lower into the ground can disrupt the foundation of the house. This can cause stucco cracks, and other foundational problems.