Problem Solving Forum
February 17 - February 21, 2014
What’s the best way to determine if a cementitious-based mortar used to repair exterior concrete is ready to be coated?
William Slama of International Paint/Ceilcote Products on
February 17, 2014:
Dhinesh has most of the answer right. However, sev ...read more Dhinesh has most of the answer right. However, several high- strength, fast hydrating cementitious repair mortars are being used that allow much faster recoating. Some can be recoated with epoxy systems in 24 hours and vinyl ester overcoats in as little as 48 hours. Note that a secondary surface prep is required. That could be either abrasive blasting or 5,000 psi water blast with pulsating nozzle to remove any possible laitance or weak surface residue. Then, prior to overcoating, the plastic sheet test (ASTM D4263) should be run to verify dryness.
dhinesh narayan of Auckland Abrasive Blasting & Coatings (2005) Ltd on
February 16, 2014:
For larger repair areas, use the plastic method to ...read more For larger repair areas, use the plastic method to assess moisture content, or, if possible, allow at least 14 days curing and then sweep blast the repaired area.