The entry to our neighborhood has two walls with signs approximately 25 years old. Each wall has about 750 ft2 of surface area. They are built on a concrete foundation with concrete blocks originally covered with mortar wash and stucco. Sometime in the past an elastomeric coating was applied. The horizontal top surfaces have hairline cracks and appear to be a main source of water intrusion. There are quite a few visible places on the vertical wall surfaces where the elastomeric coating has bubbled and can be easily removed with a razor knife. The block appears to be generally sound underneath and has not started to crumble. There is mildew along quite a few of the block lines visible from the surface of the elastomeric coating. The coating on the majority of the vertical surfaces, however, appears to be adhering well. Two general methods of repair have been suggested: 1) power wash, scrape and rotary grind all coating that is not adhering which can be found and applying another coat of elastomeric. 2) scrape and rotary grind all coating that is not adhering which can be found, prime, apply a fiberglass base and then applying a non-elastomeric coating system. There may be other methods as well.

What in your experience is the best way to restore the walls or have they reached the end of their useful life?

 

You definitely want to clean what is there. I'd probably wet it, spray on a bleach/water solution [maybe add TSP] let is set but not dry and then pressure wash.

I don't know that I've ever seen an elastomeric paint bubble/peel but most any coating will pop if moisture gets behind it. Maybe it went too long with too little maintenance. I'd be inclined to go with option #1. Assuming the cracks aren't big enough to require mortar, I'd caulk them, prime and apply a fresch coat of elastomeric.

 

aquafin's ' 2k/m ' (no $ interest) - flexible, tenacious, elastomeric concrete which can be tinted in any color you wish,,, as usual, prep is the keyword,,, IF your cracks are wider than 1/8", you should clean & seal 'em 1st w/same material,,, we routinely refinish the same type of signage in atl -3,500psi 4gpm w/turbo nozzle pressure wshr & diamond grinders IF nec

1 more thing - don't ***** about the mtl's price IF you want it done right

 

Thanks for the replies! Looks like this may be an expensive project.

 

depends on your definition of 'expensive',,, if this is the main entry into a house-on-wheels park, i'd agree,,, $500K & up homes ? depends,,,,,,,,,,,,,, how do want your n'hood to appear to passing traffic ? everyone understands 'curb appeal' these days