How to buy the best stucco siding, including advantages and drawbacks, with helpful a diagram of stucco wall construction.
Stucco is a traditional compound made from fine sand, Portland cement, hydrated lime, and water. Different kinds of cement are used in the stucco mixture, depending on the climate and on the texture desired: smooth, raked, or swirled. For an extra-coarse finish, sand-or even pebbles-can be mixed in. Pigment can be added, as well, or stucco may be painted.
Stucco is usually applied wet in three coats over a base of wire mesh, building paper, and plywood sheathing, or it can be applied over framed or solid surfaces such as concrete block or older stucco. The stucco may be troweled on by hand, and newer polymers can be sprayed on. A day or two must elapse after the first coat and between the second and third coats as well to allow the previous layer to dry.
After the final layer is applied, the stucco must be kept moist for a few days so it can cure nicely (drying too quickly weakens it).
Stucco must be applied by a professional, and with only an annual hosing down, it can last for the life of the home. It is fireproof, durable, solid, and seamless, though it can crack with building movement.
Stucco is also porous, so moisture passes through it. In warmer and drier climates, painting doesn’t affect this process as much as it does in colder climates. Check what local contractors advise before you paint stucco. If painting is an option, choose a 100 percent acrylic latex paint specially formulated for stucco surfaces.