Stucco Siding: What You Need To Know

What is Stucco Siding?

Stucco siding is a general term that refers to an exterior surface coating for homes. This siding option is made by mixing Portland cement, sand, lime, and water. Unlike other types of external cladding options, stucco siding needs to be applied to an adequate base. Unless your home is made from cinder blocks, straw bales, or some other type of solid material, you will most likely have to create a lath base to apply the stucco plaster. Stucco siding, then, is the final, visible coating of your external cladding.

In most cases, the builder will apply stucco siding in several coats. Professional plasterers might make their stucco mixes, including natural clay pigments and other custom touches. However, it is also possible to purchase pre-mixed stucco finish at most hardware or home improvement stores. When applied correctly, stucco siding offers a stable, durable, and seamless home exterior. It is naturally fire-resistant, relatively low-maintenance, and durable if protected.

What Does Stucco Siding Look Like? 

Stucco siding offers a beautiful, natural, and colonial-style look to your home. Because pigments can be added directly to the stucco mix, there is virtually no limitation to color options. Also, stucco siding allows homeowners to add custom textures and surfaces to their home exterior.

Is Stucco Siding Environmentally Friendly?

As with most building products or elements, there are both environmental advantages and drawbacks to using stucco siding. On the plus side, stucco siding is mainly made from natural materials, incorporating very few (if any) chemical or synthetic products. On the downside, most commercially available stucco siding products contain large amounts of Portland cement. Due to the calcination process of limestone, fuel combustion in the kiln, and the energy-intensive manufacturing process, the cement industry contributes to about 5 percent of global anthropogenic carbon dioxide emissions. Many green building strategies focus on reducing cement in our homes to reduce our carbon footprint.

Fortunately, there are more planet-friendly stucco siding alternatives. One way to make stucco siding "greener" is to cut out the Portland cement and add more lime. Using just slaked lime, water, and sand in a stucco mix will cut the greenhouse gas emissions associated with traditional stucco. Also, through what is known as "the lime cycle," the limestone used in this type of stucco can reabsorb some of the CO2 released during production. Check out this Rise article for a more detailed discussion on how lime mortars and plasters can help reduce your home's carbon dioxide emissions.

What Are Some Sustainable Stucco Options?

Eco Stucco is one pioneering company that is producing ready-to-use, lime-based stucco siding. Eco Stucco has a product line with limestone, sand, and water-based product line that includes over 200 different color tones. They also offer four different exterior textures to help create a custom look for your sustainable stucco siding.

There are also a few modern stucco siding alternatives that can increase your home's energy efficiency and thermal performance. Exterior Insulation Finish Systems (EIFS) is a type of insulation board coated with an acrylic finish. These boards offer continuous insulation increasing the R-value and overall energy efficiency of your home, and can be used as a high-performance lath base for a final layer of stucco siding.

Is Stucco Siding Healthy?

Stucco siding is generally considered to be one of the healthier exterior cladding options. Traditional stucco does not include any chemical or synthetic adhesives that could off-gas into the area around your home. For this reason, one leading website on limiting chemicals in your home considers stucco siding to be among the top options for non-toxic siding for homeowners who are severely sensitive to volatile organic compounds (VOCs). However, it is worth mentioning that some modern stucco siding products incorporate a type of acrylic blend to provide a small amount of flexibility. Though this can lower the possibility of cracking in the stucco, consider avoiding these options if you are looking for a completely zero-VOC choice for your home siding.

What are the Benefits of Stucco Siding?

Some of the benefits of this popular siding option include:

• Stucco provides a stable, locked-in color. Both cement and lime-based stuccos can often add pigments directly into the mixture. This feature means that the color is part of the stucco itself rather than being painted on after the fact. It adds a level of color-fastness to your siding and reduces the sometimes tedious task of having to repaint your home exterior every couple of years.
• Stucco offers opportunities for customization as it is applied by hand. Even if you are not a professional plasterer, this hands-on exterior cladding option lends itself to DIY options. This customization is incredibly accessible if you are only adding stucco to a part of your home exterior. Stucco can be textured simply in several different styles, allowing you, or your tradesperson, to experiment with creative embellishments.
• Price. Stucco siding is usually one of the cheaper exterior siding options, especially if you choose to purchase the raw ingredients and make your mixture.
• Stucco gives a seamless seal for your home, unlike other exterior cladding options. This characteristic helps protect against driving rain and snow and can also ensure an airtight building envelope.
• Stucco can also add a layer of fire resistance to your home. A three-coat application of lime or cement-based stucco siding will give your home at least a one-hour fire rating. This rating means that the stucco will protect the stucco's wooden components for at least one hour from direct flames.

What Are the Downsides of Stucco Siding?

Some of the drawbacks of this popular siding option include:

• Regular Maintenance is Needed. Stucco siding might need regular maintenance, including regular sealing and cleaning.
• High Labor Costs. Applying stucco to your home is a labor-intensive process. Though the materials are relatively cheap, professional plasterers can charge high amounts for application.
• Cracking. If you live in a climate with high-temperature variance, cracks and fractures in your plaster may develop. This damage can lead to water infiltration, which could cause mold issues affecting your home's frame. Any visible cracks need to be fixed immediately.

How Much is Stucco Siding?

Commercially available bags of stucco are also relatively inexpensive. For example, Home Depot offers a 50-pound bag of fast-set stucco siding for just over $16. If you are hiring a professional to stucco your entire home exterior, however, labor costs can quickly add up. HomeGuide estimates that the average cost to stucco a house exterior is $7 to $9 per square foot or around $8,000 to $12,000 for materials and labor.

How to Seal Stucco Siding?

In dry climates, stucco siding usually does not require any sealant. However, suppose driving rain or moisture accumulation is an issue in your region. In that case, it is usually a good idea to regularly seal your stucco siding. You can use a clear, concrete, or masonry sealer for sealing stucco siding. This product can penetrate the porous structure of the stucco and thus avoid moisture entrance. You'll find both silicone and polyurethane-based sealants for stucco siding. Depending on the level of exposure to the elements, homeowners should expect to reseal their stucco siding every 5-10 years.

How Long Does Stucco Siding Last?

Stucco siding, when properly applied and maintained, can easily last 50 years. The primary consideration affecting its durability is a proper and quick repair. If cracks and other damage are not repaired well, moisture can accumulate under the stucco and compromise its structural stability.

How Do You Make Stucco Siding?

If you are willing to do the work yourself, stucco siding is one of the cheapest siding options on the market. All you need to do is:

• some river sand 
• a few bags of hydrated lime
• Portland cement, and 
• powder pigment 

The following ratios should be observed:

• Scratch coats: 1 part cement, 1 part lime, 2-1/4 to 4 parts sand
• Brown coats: 1 part cement, 1 part lime, 3 to 5 parts sand
• Finish coats: 1 part cement, 1 part lime, 1-1/2 to 3 parts sand

Once you have your plaster ready, check out this YouTube tutorial on properly applying and smoothing out the exterior plaster for your home.