Research Decorative Concrete
Ask-the-Expert Advice: Fixing Stamped Concrete; Working with Stains; Fixing Concrete with Overlays; Concrete Sealer Q&As; View All Expert Advice
Construction Materials: What is Concrete Made of; Concrete Mix Designs; Decorative Mix Design; Concrete Admixtures; Ordering Concrete
Special Types of Concrete: Glass-Fiber Reinforced Concrete; Precast Concrete; Post-Tensioned Concrete; Self-Consolidating Concrete
Basics of Construction: Surface Preparation; Subgrades and Subbases; Hot Weather Concreting; Cold Weather Concreting; Curing Concrete; Building Concrete Slabs; Joints in Concrete Slabs; Preventing Concrete Cracks; Green Building with Concrete; Concrete Demolition; Making Concrete Slip Resistant; Concrete Forms
Waterproof & Protect: Foundation Waterproofing; Vapor Barriers; Common Sealer Issues; Polyaspartic Coatings
Concrete Applications: Concrete Overlays; Concrete Footings; Poured Retaining Walls; Commercial/Industrial Floors; Concrete Floors: Owner's Manual; Concrete Parking Lots; Rock Salt Finish; Tilt-Up Concrete; Form Liners for Cast-in-Place Concrete; Fiber-Optic Concrete Countertops
Maintain & Fix: Cleaning Concrete; Concrete Repair; Fixing Concrete; Snow Melt Systems
Marketing Concrete: Tips for Concrete Showrooms; Marketing Ideas - ConcreteSherpa

Curing Colored Concrete

By Chris Sullivan – ChemSystems, Inc.

Question:

This integrally colored floor was cured with a non-breathable curing paper. What are the white marks on the surface, and how do we remove them?

White haze is left behind after removal of a
nonbreathable curing cover.

Answer:

A non-breathable curing material will create a vacuum that sucks moisture from the concrete up to the surface. The moisture then has nowhere to go because it is trapped beneath the non-breathable covering. Anything carried to the surface along with all that moisture (such as natural salts in the concrete) will be left on the surface as the moisture evaporates once the covering is removed.

The white haze on the concrete surface seen in the picture is dried salt residue, or efflorescence, that was left behind when the cover was removed. Non-breathable curing membranes tend to create more efflorescence because of the dramatic vacuum they create when placed on wet concrete. A breathable covering is always preferred, especially on colored concrete.

In this case, using lots of water to remove the surface salts while they were still wet would have minimized the white haze. Now, however, multiple passes of a rotary scrubber with a scrubbing pad are needed to remove the deposits.

Find Concrete Curing Products