Remove the Sprayed Stucco on Siding
Q. Stucco was sprayed on to the exterior of my house, which is cedar clapboard and siding, without any primer first and no sealant after. To its credit, it has held up for about 25 years. Now, many chunks of stucco are simply falling off and are easy to pick off. However, there are many sections that will simply not come off. This stuff is about 1/16-inch to 1/8-inch thick. Any ideas on how to get it off?
A. You may need a larger scraper. There is no solvent for stucco over wood so far. Mortar products stick really well to many things, and wood is one of them.
If you want to remove the existing sprayed-on stucco, the answer is to re-stucco. If you want to remove the existing stucco to paint over the wood, that is another objective. In either case, all the existing stucco would have to be removed, which involves a lot of work. To stucco over places where the existing stucco is not removed, two applications are required: First, level the entire surface; second, coat to cover the entire surface. In this manner, no bumps would be seen between the areas where some existing stucco remained and some was removed. The same applies if painting over was to be done. You have to somehow fill in to level the surfaces to obtain a leveled finish surface.
Tex Cote has an undercoating applied to the wood first. It serves as an adherent for the sprayed on stucco and a water proofing undercoating. Where it is applied correctly, the stucco remains. Where it is not, the existing stucco peels off or flakes off. So to get the final results wanted, you decide what you want as the final results.
Sand blasting would leave marks and sand in the wood, which would have to be sanded out and filled in to obtain a smooth final finish. Paint fills in nothing. Sand blasting would work if restucco were to be done. A sealer would need to be applied to the wood first. The sealer would also need to have the adherent to bond with the stucco. If you fail to use the correct sealer, the stucco would look nice at first but would soon fail and peel off again.
It is not suggested to attempt to do restucco or paint over existing stucco without first removing all the existing stucco. Without doing so, the final results would not look good, and it would appear to be a patched up job.
If the stucco is really hard to get off, try a blowtorch and scraper. Hold the blowtorch just far away so as not to start a fire. The bond bubbles right up or 'pops' right behind, then zap it up with a paint scraper.