Our below-grade, painted poured concrete garage wall is showing some efflorescence and mild spalling (see image). I would like to cover it with one or two coats of stucco. I am made to understand I may need to do all of the following, but am a little uncertain of the order:
- Wire brush away any loose concrete.
- Treat efflorescence with acid.
- Wash wall (with TSP, say. A power wash is not going to work here).
- Maybe fill in those 'tie holes' with something?
- Coat the wall with a bonding agent (like Weld-crete), as it is painted.
- Wet the wall prior to applying stucco.
- Apply stucco (OK, this is certainly last).
I don't understand if the wall is to be sprayed down prior to stucco if it has bonding agent on it--will this wash off the bonding agent? How do I fill in the tie holes? My goal is to prevent further spalling, do I really need two coats of stucco, or would one do? Am I crazy to attempt this myself?