Stucco is essentially a cement-based material and therefore, is liable to cracking. Furthermore, much like every other historic building material, stucco is very susceptible to damage from the elements, especially water (even though it usually has a protective coating). While extensive damage may require specialist Stucco contractors, there are some things that can be done yourself, here is a quick guide.
The term 'stucco' refers to a particular type of exterior plaster that is generally applied with a two- or three-part coating. Stucco is usually applied directly onto the building's main material underneath. While this is usually masonry, Stucco can also be applied to wooden frame structures. For the most part, badly deteriorated Stucco will be due to water infiltration into the building's structure. However, there are a number of things that can actually cause damage and these should be addressed before any Stucco repair is carried out.
Damage through water infiltration will usually be due to water entering the building's structure though the roof, or perhaps around chimneys, windows and door openings. Infiltration can also be caused by excessive ground water getting in from the foundations. Further possible causes can include the following: - Incorrect installation of any wall component - Excessive shrinkage of green lumber - Any excessive building movement - Thermal contraction or expansion - Carrying out the installation of any interior wall board or 'loading' the roof after the stucco has been applied. - Poorly fitted or ineffective guttering - Excessive interior condensation or humidity
Repairing the Stucco
You will need to repair any damaged Stucco much in the same way that you repair plaster. The first thing to do is to remove all the loose Stucco. This should be done until you are either down to the 'lath' or down to the masonry if the Stucco is applied directly to it. Ensure that the surface is clean To ensure that a good bond is obtained between the Stucco and the substrate, the surface should be entirely cleaned. Use a bristle brush to remove any remaining debris including any dirt or plant growth, as well as any remaining paint, grease or oil. Create an indent More often than not, the brick or stone mortar joints will then need to be 'raked out'. This should be done until there is an indent approximately 5/8-inches deep. This will make sure that you get a secure bond between the substrate and the new Stucco. To make sure the job is done as neatly as possible, the area to be repaired should be squared-off with a butt joint. You can then simply plaster the new Stucco to the substrate.