What is the Stucco?
Stucco is typically a cement, sand and lime mix with water. This would also be referred to as traditional stucco,1 or 3 coat stucco, or straight cement plaster . Normally, we consider stucco as referring to a durable exterior coating. Plaster is a more generic term for a plastic (wet) material that is used for coating and finishing a wall that will harden over time. This can be with a base of cement but might also include clay earth, Gypsum papercrete or many other things. Although the distinction is blurry, many people think of stucco as exterior stucco siding and plaster as an interior finish.
Stucco: One coat stucco vs. Three coat stucco
Stucco- Both One coat stucco and traditional Three coat stucco is a material made of an aggregate, a binder, and water. It is applied wet and hardens to a very durable solid. It is used as a finish coat for interior walls, exterior walls, ceilings and decorative detailing.
Originally stucco was made of hydraulic lime, sand and water. Three-coat stucco (aka “Traditional Stucco) is made from blends of lime, cement, sand, and water. Lime is added to increase the water resistance and workability of modern stucco. The three coats, which are the scratch coat, the brown coat, and the finish coat provide a total thickness 3/4 of and inch or more. Each coating or layer would have finer sands or more lime than the coat before it.
One Coat stuccois a newer application that is similar to traditional stucco. “One-Coat” is also a misnomer, as AT LEAST two coats, a base coat and a finish coat, are applied. The One-Coat system offers design flexibility, durability, and water management. Additives such as acrylics and glass fibers are added to improve strength and flexibility and reduce cracking. Each one-coat system is a proprietary mix of Portland cement, fiber reinforcement and SECRET ingredients. As a blended proprietary mix, One coat stucco manufacturers provide the extra training an instructions to ensure their products are used within their specific guide lines.
As building speeds have increased, more masons are turning towards One Coat as a faster method while still having the durability of traditional cement exterior stucco.
What is the Re-dash?
Re-dash consists of a single layer of the Portland cement, with colorant applied to cover and freshen the surface. Repairs are made to cracks and minor imperfections in the surface and then the new coat is applied. This will provide a new look and keep with the integrity of the existing finish. If a new texture is required, a thicker coat is required, and can add additional expense.
It is the nature of stucco to experience some cracking. These small cracks are normal and do not require any maintenance or repair. If a crack exceeds 1/8 of an inch in width then the crack should be repaired. Repairing stucco cracks is completed by adding a small amount of stucco to the crack. Do not put caulk into the crack. If you experience a crack wider than 1/8 of an inch please contact your contractor so the proper resolution can be determined. Typically a larger crack can be broken back and patched or an expansion joint can be added.
Yearly Inspection and Cleaning of Stucco
Stucco should be inspected annually for holes, significant cracks, or separations. If stucco repairs are needed, it is important to have the repairs completed in a timely fashion to prevent damage to your home. A mild cleaner and water can be used to remove most stains. Pre-wetting the surface will overcome some absorption of dirty wash water from being absorbed back into the dull finish. Use of a garden hose and a jet nozzle in combination with a mild cleaner will clean effectively. Do not hold the nozzle to close to the surface because the high pressure may erode some of the finish. Pressure washers are not recommended because they will erode the finish and can cause damage.
Stucco comes in an infinite number of colors. These colors are made by placing an additive into the cement mixture prior to application. The color is throughout the layer and will not fade like a painted finish. The full curing time for stucco is typically several years. During this time you will notice several color changes from dark to light, and then back to dark as the finish sets and the excess moisture evaporates.