More About Stucco

Stucco became a term for exterior plaster. When is unknown.  Stucco has been used (exterior plaster) for 1000s of years, some historians say the pyramids were plastered white, over 4000 years ago. But what changed stucco, was the invention of Portland cement in 1843.   In England, in a bricklayers kitchen, heating limestone hotter and hotter, found that it gave it more strength.

Stucco, or portland cement plaster, is a versatile facing material that can be applied to flat or curved surfaces either inside or outside any building or structure. Stucco has been used for more than a century as a surface finish because of its utility, low first cost, and minimum need for maintenance. Some advantages of stucco include a natural resistance to fire, lasting durability, and once again, what every real estate owner loves, it’s low maintenance.

Traditional stucco consists of portland cement-based materials and sand, mixed with water to form a workable plaster. Portland cement plaster is applied either by hand or machine to the exterior and interior wall surfaces in two or three coats. Stucco may be used to cover less visually appealing construction materials, such as metal, concrete, cinder block, or clay brick and adobe.

Stucco is used for facing in a wide variety of commercial and residential structures. It may be applied directly to a solid base such as masonry or concrete walls, or it can be applied to a metal lath attached to frame construction, solid masonry, or concrete construction.

Durability and breathability are the major sustainability benefits of cement stucco.  Stucco is a water-shedding, hard, impact-resistant, fire-resistant, and color-retentive, exterior finish material. Because plaster is breathable, or able to transmit moisture vapor, water that gets behind it does not become trapped. This means stucco is resistant to rot and fungus, helping to protect indoor air quality. Stucco has proved to be a durable wall cover in all climates, whether wet, dry, hot, or cold.

 The final appearance of the finish coat can be varied by changing the size and shape of the aggregate, using colored cement, adding pigments, changing the consistency of the finished mix, or changing the method or equipment used for plastering.  By using integral color, the need to paint is eliminated.

Frame construction. Stucco has been used over frame construction in the United States for more than a century, long enough to develop proven procedures for installation. When stucco is selected as the exterior surface for frame construction, metal lath is attached to framing members. Vapor permeable, the water-resistant paper is applied over sheathing before attachment of the lath. The paper protects the sheathing and interior of the wall from outside moisture intrusion without trapping moisture vapor in the wall.

Color is determined by selecting cement and aggregate color, and quite often modified by adding mineral oxide pigments to the plaster mix. In many areas, factory-prepared finish-coat products are available. Pre-pigmented packaged cement can be used to achieve the desired stucco color or pre-weighed mineral oxide pigments can be added to the finish coat stucco during mixing. Stucco can be finished with natural color or can be mixed to produce any preferred color. Some contractors tend to use warm colors such as yellow, pink, or orange. Beige is one of the most favorite colors used in stucco. However, when speaking of colors, white has always been preferred over other colors. Of course, white is always good for any home.

The texture is achieved by selecting an aggregate size, controlling finish mix consistency, and using special treatment techniques during and after application of the finish coat plaster. Texture gives substance and character to the plaster surface. It can be used to provide highlights, depth, continuity, segmentation, and even achieve the look of a completely different construction material such as wood timbers, brick, or stone masonry construction. A sample panel should be requested prior to construction to confirm the suitability of a desired color and texture.