Cement siding is strong and durable, but it does not last as long as other types. It also varies in texture over the surface, which means that it is most commonly used with certain styles, such as tabby shells. Synthetic, or acrylic, stucco is a newer form of stucco that provides some extra uniformity.
It is suitable for all three layers of application, thin-coat installation, and EIFS installation. Synthetic stucco 2 is softer than traditional stucco 8, which is hard and rigid.
Aside from some slight variations, it is hard to tell the difference between natural and synthetic stucco unless you know what to look for. If there is a hole in your stucco, you can look for the underlayer. Natural stucco usually has a mesh underlayer, while synthetic stucco usually has a foam core.
You can also touch the stucco and consider the texture. EIFS is the latest development in stucco materials. It stands for Exterior Insulation and Finish System and comprises many thin layers over foam insulation, with a topcoat designed to resist moisture.
It is made by using an adhesive to apply the foam to the substrate, then a base coat is put on the foam board. Mesh or lath is embedded in the base coat and allowed to cure. From there, the finish coat is added.
The finish coat contains polymers that make it more flexible, less likely to crack, and more water-resistant. Like the other types of stucco, it can be pigmented and finished with different textures. Some methods are more common than others, but a few are highly specialized.
Most do not add additional costs to your project. Projects that require additional material like tabby shell stucco have higher costs than standard finishes. Dash is the most common stucco texture and the one associated with most stucco homes.
This is a rough texture with a pronounced appearance and deep shadows. This texture works on nearly any type and home style. Pebble dashing is the process of putting small pebbles or pea gravel into the wall after the final coat of stucco.
This gives you a solid, textured wall of stones. This is a less common finish than most stucco walls using only the plastering materials. It often has no additional costs because the pebbles can be tossed or thrown on the wall quickly, and the finish needs less plaster.
A skip trowel finish, also known as a lace finish, is a fast and easy way to texture a stucco home. It can be sprayed or hand-troweled on and works best with traditional stucco.
It can also hide repairs easily. This texture can be rough, with high casts and shadows, or smoother and more refined. This can also change over the house and add more depth. Float stucco is the more commonly known name for the sand texture.
This is a more lightly textured stucco than the popular dash texture. The result gives the stucco a wet sand appearance. A float stucco is a good option if you want something smoother than dash but want some texture.
If you do not like textured stucco, you can give it a smooth finish instead. This is a much less common option than most other stucco finishes. It takes time and must be applied by hand. If it cracks, like stucco frequently does over time, the cracks are more noticeable in the smooth finish.
It can also be more difficult to repair and blend this texture than others. The Santa Barbara finish is most popular in California, where it originated. The Santa Barbara finish is halfway between a smooth and textured finish. It is very lightly textured, with some small sand particles added to the plaster. The finish is applied with a pool trowel, which helps get the specific semi-smooth appearance. The English stucco pattern is very distinctive from other textured stucco appearances.
Instead of a rough finish, the English stucco is made by smoothing the stucco in a circular pattern. This is a slightly more decorative finish than most of the others.
It is not as common and should be done with the traditional stucco rather than one coat or synthetic materials. One of the more unique textured stucco finishes is the cat face. This unique texture is mostly smooth, with textured areas showing through. When done correctly, it looks as though a cat is peeking through the stucco. The cat face texture can be large or small, and it can be close together or more spread out.
This means that there is still a lot of room to customize your stucco with this finish. The tabby shell stucco is a unique finish for stucco homes. Rather than allowing the plaster to show or covering it in pebbles or sand, the plaster is completely covered in shells.
It must be applied to traditional stucco and cannot be used with thin-coat or synthetic materials. It also adds some strength - tabby walls last longer than other stucco walls without repair. Get free estimates from stucco siding installation companies near me Get Free Estimates. Applying stucco to a home is a fairly labor-intensive process. No matter which system you use, the various layers and materials must be applied by hand. With traditional stucco, there is also a considerable curing time between each layer.
This curing must proceed at the correct rate to prevent cracking and shrinkage in the siding. Each of the three types of stucco has related labor costs. Traditional stucco tends to be the most costly to install because of the time needed between coats, while thin-coat stucco is the least expensive.
Thin-coat stucco is sometimes known as one-coat stucco. It is also a hard stucco, like the traditional, and may sometimes be referred to as hard-coat stucco. It is relatively uncommon in most areas, and it may be difficult to find an installer who has worked with it before. In this case, a metal lath is used like in traditional stucco. But rather than applying a scratch coat and brown coat, a single coat of material mixed with fiberglass is applied directly.
This makes the installation process much faster because you do not need to wait for each coat to cure before applying the next. The finish coat is applied right away and has the necessary strength from the beginning. It can also be pigmented and finished with various textures. However, thick textures and textures that require other materials like pebble dash or tabby cannot be used with this system.
Because it takes less time to install and requires less material, it is also less expensive. EIFS stucco is much more labor-intensive than one-coat stucco, but it can be easier than three-coat.
This system starts by applying a layer of foam insulation to the exterior. Then a scratch coat is applied, with the lath embedded in it. From here, thin layers of synthetic material are applied one at a time. They cure faster than the three-coat system, even though there are usually more layers involved. After that, the paper goes on the wall to protect the under-layment wood in particular, masonry surfaces do not need paper and is installed from the bottom up, to allow water to drain along the paper without ever touching the wood underneath.
Next comes the wire. The wire is a 17 gauge chicken wire type of netting, but has some unique characteristics to it that allows the cement to tie into it. If you were to use regular chicken wire, the mud would not stick as well and may even fall off of the wall in some areas. So only use the specified 17 gauge, self furred stucco netting. After you have put up the wire, it is time to add the corner aid and arch aid where they are needed.
They are used on virtually every house and are the main components that form the edges of stucco walls. The scratch coat is a base coat and the first one to go on the wall. It is applied with a hawk and trowel and a scratcher. After the cement is on the wall, a scratcher is used to make horizontal lines in the stucco mix, in order for the next coat the brown coat to stick to it. Let the necessary amount of wire hang past the corner so you can attach it afterwards to the stud around the corner.
Next, put a staple in the top of the wire, right at the corner of the building. This will hold the wire in place while you roll it out along the wall.
Staple the top edge of the wire along the entire length of the wall, stretching it a little as you go and making sure that the bottom edge of the wire is still straight with the weep screed. First, run your hand down the middle portion of the paper, starting from the top and working downwards. As you slide your hand down, you are ensuring that it is laying flat against the substrate and there are no major wrinkles. Throw a few staples in the paper after the paper is taught.
The rest of the runs are simple, you just need to have enough overlap on where the wire meets both horizontal and vertical joints and you work the wire the same exact way. Staple the top edge first, making sure you have three bubbles overlapped and staple the top of the wire along the entire wall. Then tighten the wire and staple it off using a 6 and 12 pattern.
To keep things simple, just make sure that the overlap on the new piece of wire is three rings, like the picture illustrates. Use the same method that we used for the first piece of wire, stapling the top edge along the entire wall, working the center of the wire down and then working outwards in both directions from there.
The outside corners will get wrapped around the corners and then our new piece will overlap that starting at the corner, making a neat and clean transition. We will want to staple the wire to the corner before we wrap it around the corner, this will prevent bubbles from forming and make a nice sharp turn. Start by stapling the middle of the wire and then stapling the top and bottom edges.
On a building with relatively small unbroken fields of stucco exterior wall, often no expansion joints were used. But where stucco is applied over metal lath on wood framing, the Portland Cement Association recommends expansion joints every 10 feet, forming panels of no more than square feet. Expansion joints are used in some other stucco installation methods as well. Our second photo below-right shows an insulating-board based Stucco-wall expansion joint on an elevator tower on the Vassar College campus, Poughkeepsie, NY.
Expansion joints are particularly critical at joints between dissimilar materials, such as where wood framing meets masonry, or wherever excessive movement is expected, such as the band joist area between two stories. Stucco will bond directly to most masonry surfaces, but on sheathed walls the stucco requires metal lath to form a mechanical bond to the wall. Lath should always run perpendicular to the studs, and expanded metal lath must be installed with the correct side pointed up or the plaster will slip off when troweled on.
Our photo left shows exposed metal lath in the stucco exterior of a poorly-finished home in New York. It looks as if the top coat of stucco may have not been applied at all. The expanded metal lath used to support stucco on building exteriors or interiors as well is nailed or stapled approximately every 6 inches at studs and other framing members. Galvanized staples are now widely used to attach metal lath.
Another common stucco lath problem, according to Webber, is that lath installed too tightly at corners causes poor embedment of the mesh at the corners. This will cause cracks at the corners as the building undergoes normal movement with changes in temperature and humidity.
Another option is to pull the lath away from the building at the corners to make sure it is properly embedded. The corners at either side of window and door headers is another common location for stucco cracks.
To reinforce these areas and reduce cracking, some contractors add a second layer of reinforcing at these corners using a rectangular section of metal lath placed diagonally at each corner.
The metal lath should form a continuous layer around the building with all laps wired together and vertical laps staggered. With large-mesh reinforcement, lap vertical and horizontal joints at least one full mesh and a minimum of 2 inches.
For small-mesh reinforcement, the laps should be at least 1 inch. Excerpts are below. Stucco is a mixture of Portland cement, sand, and water, with a little lime or a plasticizer added for workability.
A proper mixture has good tensile strength and weather resistance and the ability to bond well to the mesh or substrate.
It is also easy to trowel on and resists sagging. In cold climates, it must also have freeze-thaw durability, usually obtained by using air-entrained plaster.
The cement base can be masonry cement, plastic cement, or Portland cement, which may have air-entraining additives. Do not add lime or a plasticizer to masonry cement or plastic cement since these already contain plasticizers.
While approximate proportions are well established, the right mix for a job depends on the weather exposure of the wall and weather conditions during application see Table Other than the right proportions, the keys to a good stucco mix are clean, good quality sand and clean potable water. The sand should be free of vegetable matter, loam, clay, silt, and soluble salts and should conform to ASTM C, which designates the distribution of particle sizes gradation.
Impurities in the sand or water can affect the strength of the mix, and poor grading of the sand will hurt its workability. Stucco can either be hand troweled or blown with a machine. Some stucco contractors use a pump for the base coats but apply the finish coat by hand.
Although the mixes are slightly different for the two approaches, both can produce a high-quality finish. While still wet, the plaster is scored horizontally with a special metal rake or trowel to create a good mechanical bond with the second coat vertical scratching promotes cracking at studs.
For proper curing, the scratch coat needs to be kept moist by misting or fogging with water for 48 hours. Except in very moist weather, misting should start as soon as the freshly applied stucco lightens in color and be repeated at the start and end of each day until the second coat goes on. The second coat fills any cracks in the scratch coat, and the additional sand in the brown coat helps prevent new shrinkage cracks.
A short delay between the first and second coat helps to create a good bond between the two and strengthens the scratch coat by rewetting it for a more complete cure. In the Southwest, where adobe is popular, the brown coat is often steel troweled for an adobe look and serves as the final coat. After the second coat is allowed to cure for a minimum of 7 days 14 will allow a more complete cure , the top coat is applied to provide the finish color and texture.
Many contractors now use premixed color coats, some with acrylic additives to increase water resistance and flexibility. Creating a uniform color and texture requires a skilled applicator, uniform mixing, favorable weather avoid direct sun , and a uniform substrate without variations in texture or water absorption. Problems in the substrate will tend to show through the thin finish coat. It is best to do an entire side of the building in one batch with no cold joints. A modest amount of color variation is considered part of the character of traditional stucco, but too much is a sign of substandard work.
A certain amount of shrinkage cracking is also inevitable in stucco exteriors. Application over wood-frame construction results in more cracking than over concrete block or other more stable substrates. Coarse textures in the finish will tend to hide the cracks better than smooth finishes. Generally these do not leak or indicate substandard work. Moisture , humidity, rain, or wet conditions during thin-coat or EIFS stucco work can lead to a subsequent series of failures of the entire installation.
The home shown in our photo left was the subject of litigation. We observed that the final stucco had been applied over wet surfaces and in some cases over surfaces that also had been troubled by soil that had splashed-up on the building during rainy weather.
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