Selected Answers

From Zenith Czora of Durotech Industries, Inc. on March 25, 2019:
The standard practice for coating cementitious-bas ...read more The standard practice for coating cementitious-based mortar is to allow the mortar to cure for 14 days prior to painting with water-based paints, or a minimum of 28 days when oil-based paints are used. Prior to painting, the moisture content of the substrate must be checked. The moisture content should be not more than 5.5%. The pH of the substrate should be checked also to make sure it is not too alkaline for painting. pH of 10 or less is typically desirable. The pH can be checked by using a pH paper. Using  highly-alkaline-resistant water primers are highly recommended to inhibit the occurrence of efflorescence.

From Richard Devick of UCI PAINTS on March 25, 2019:
Check the pH of the cementitious patch. Ideally, i ...read more Check the pH of the cementitious patch. Ideally, it should be less than 10. Hydrating the area with periodic water wash will help “cure” the concrete, minimize surface fissures and insure the proper strength.