Newbie here! - Stucco exterior

[kjb2011]

I’ve been looking at buying a pre-built house with a stucco exterior finish. It has small cracks throughout the stucco. What causes these and is it serious? Should I avoid buying a stucco home?

Thank you!

[N2Deep]

The small cracks are the same thing that happens to concrete. Since stucco is basiclly a thin layer of sand/morter applied to the wall it will eventally develop small cracks. Only snythetic stucco is flexible and tends to hold up better. To repair it you should caulk all cracks to seal them and then paint the stucco to cover up the cracks. That should do the trick. If they are large cracks they should be patched correctly with stucco and you may have to repaint to ensure a uniform color.

[eifs]

Hard-coat stucco systems will always crack because it is basically a one inch thick concrete wall. The rate of cracking depends on quite a few things; some are whether there are proper expansion joints between dissimilar materials, the caulking at all terminations, the mixing ratios of the sand and cement, the curing procedures, the maintenance of the structure and finally the application from scratch to brown to finish.

On older homes the stucco cracks can almost always be attributed to the structural movement. These cracks are unsightly and are points of entry for moisture which can lead to a host of other problems. Fortunately, hard-coat cement stucco has a relatively high permeability to moisture which usually allows quick drying of the interior surfaces with no serious damage. No amount of caulking will stop the cracking but it will stop the moisture. The best way to bring back the curb appeal of damaged stucco is to rerun the finsh coat (sand ,cement and lime) on the entire structure.

Having said all that, hard-coat stucco has been around for litterally thousands of years because of its excellent properties such as impact resistance and its preservation qualities. Did you know that the Roman coliseums and other structures lasted so long because of the sand and cement facades?

You can also prime the building and wrap it with a cementious basecoat used for EIFS and refinish with the EIFS finish coat. I don't recommend this unless you repair the structural cracks first, because the basecoat and finish coat are basically a waterproof cosmetic fix, which is not all bad in my estimation. The EIFS lamina is more flexible but it is only 3/8's of an inch thick. The cracks eventually will surface because they are one inch thick.

[Tom R]

Great post, Eifs.

[JCA]

Depending on the age of the home you may reconsider buying a stucco house. I don't know that much about it but I've heard lots of talk about older stucco homes rotting. There seem to be major differences in the way things are done before stucco these days.