concrete curb

I painted about 3500 feet of curb last year and now on about 150 feet the paint is completely gone. the rest of it is still good. trying to figure out what happened. the concrete is about two years old and was painted before with the same results. we pressure washed the entire curb and painted with Red latex. Any suggestions on what to do to remedy the problem.

Does this 150 feet of curb get a lot of foot traffic ?

Depending on the state if you can use it try chlorinated Rubber. I have had good luck on concrete with that. I cant imagine what would cause that.

Thinking it may have to do with how much lime/alkaline content in the section of concrete curb, maybe it was the bottom of that batch and they added more concrete and water to finish that last section of the day or job.

burton4ta wrote on Apr 21, 2015:Go to #3

Depending on the state if you can use it try chlorinated Rubber. I have had good luck on concrete with that. I can

't imagine what would cause that. Chlorinated rubber sounds like a great choice but if you can't get it I would suggest using muriatic acid to clean/ etch the concrete curb section, rinse it off with water and let dry before you top coat it with paint to give the traffic paint a "ETCHED" surface to adhere to. Check out this site about masonry/ concrete and muriatic acid: http://www.naturalhandyman.com/iip/infxtra/infmur.html

When you say "gone", did it chip or peal off, or did it fade? Is there a gradual transition from paint to no paint or a sudden change?

It is a gradual transition from paint to no paint. Paint rep took a look and some samples. He said some parts looked like the concrete it self is flaking. their signs of concrete on the back of the paint.

If the concrete is coming off with the paint then who ever finished the concrete used too much water on the surface and floated to many fines to the top. Could try water blasting to get the scale off the surface.