All About Stucco

Not everyone enjoys the plank-style look of wood or vinyl siding, and if you are one of these homeowners, you might be wondering if stucco is the way to go. As one of the oldest types of exterior siding in the world, stucco has a tried and true track record, and it is one of the greatest home additions if you are looking for fire safety. (One inch of stucco has a firewall rating of one hour, meaning it will take one hour before one side of the wall burns through to the other side.) This being said, there are places where stucco may not be appropriate.

What Is Stucco?

Stucco is a masonry mixture originally consisting of water, sand, and lime that dates back to the days of ancient Greece. Modern stucco has eliminated the lime component and replaced it with cement, a far superior construction material that allowed for longer drying times and greater workability. In the early days of its use in the United States, stucco was primarily seen in arid regions with sandy soils; areas where the weather was damp and where home foundations heaved and settled with time showcased the flaws of stucco in that it is fairly brittle and does not accommodate movement well. As time has gone on, various polymers have been added to stucco mixtures to help improve flexibility, though it remains a home finish that is not for every climate.

How To Apply Stucco

The stucco process is not an easy one. It is, by far, the most labor-intensive exterior siding process, and because of that it is often very expensive. Homes that have stone, metal, or concrete base structures will be able to accept stucco application immediately. Home made out of wood, however, will have to have a metal lathe installed. This grate-textured layer will provide the surface for what is known as a “scratch layer,” or the base layer of stucco additional layers will adhere to. The installation of the stucco itself is not complex, just time consuming. It is typically a three-layer process, with the first layer acting as the adhesive layer, the second layer (known as the brown layer) acting as the surface leveling layer, and the third layer being the layer that receives the finished texture. This texture work is done by hand with a trowel or with an air compressor attachment, depending on the style desired.

If you are determined to attempt your exterior stucco install on your own, understand that there are a number of subtleties that will make or break your stucco work. First, stucco will come to you much like concrete - it will need to be mixed. Follow the instructions exactly. If your mixture is too wet, it won’t cover properly, and if your mixture is too dry, you won’t be able to spread it evenly.

The scratch layer of stucco, layer one, should be applied evenly with a trowel, less than half an inch in thickness. After it stiffens, but isn’t yet dry, use a raking tool to notch lines in the surface. This will provide a better bond for the second layer to adhere to. Wait 24-48 hours for this layer of stucco to cure. This is a very delicate process; you do not want the scratch layer to dry completely and crack. If you suspect it is losing too much moisture, you will need to mist the surface of it as it cures.

After the 24-48 hours, the brown coat can be applied. This coating is done in the same method, also at approximately a 3/8 inch depth. The goal of this layer is to have it be as smooth and flat as possible. Fill in any gaps and cracks as you go, adding thin layers and smoothing them until the final depth is ¾ of an inch. This layer receives no notches, but also needs a 24-48 hours curing time with proper moisture control.

The third and final layer is mixed with color as desired and applied to a much thinner depth of 1/8 of an inch. This is where creativity can shine with textures and designs; however, if you want a smooth finish, you can achieve this by allowing the stucco to stiffen slightly and then going over it with a moist sponge, much as you would do if you were smoothing out an art project made of clay.

What Styles Are There?

One of the reasons stucco work is so appealing during the remodel process is that it is extremely customizable. There are over 30 different common texture finishes to pick from, and that’s if you don’t want any fancy custom work. Stucco can also be mixed with a wide range of colors, often far more than you can pick from with plank siding options. For some extra pennies, you can have a completely customized texture and color for your home. Many homeowners opt to keep their stucco white for a traditional look.

What Maintenance Does Stucco Require?

The good news about stucco exteriors, aside from their excellent fire ratings, is that they have an extremely long durability span – potentially up to 80 years. Routine inspection will be key to achieving this longevity. Stucco is naturally low maintenance, but cracks and damage can lead to mold and rot of the materials beneath the stucco. Many homeowners opt to gently clean their stucco exteriors with the garden hose once a year to wash away anything that might have found a nook to reside in. Any chipped stucco can be replaced, and as long as the exterior is in good condition, it can be painted over easily down the road for a change of pace.

Consider A Professional

Stucco installation is not cheap, and hiring a professional will make it more expensive but may be well worth the money. The complexity of this type of exterior finish makes it challenging for DIY homeowners. One wrong move and the entire project may fail or deteriorate a few years down the road.