PaintSquare.com
Follow us on Twitter Follow us on LinkedIn Like us on Facebook Follow us on Instagram Visit the TPC Store
Search the site

 

Advertisement

PaintSquare



Problem Solving Forum
When can you coat new concrete

From JPCL, January 2011

   

Comment from Martin Emore, (2/4/2011, 9:57 AM)

concrete is cured fully by twentyeight days. i think after this date one can apply the first coat of paint on top.


Comment from parviz mohamadi, (2/10/2011, 2:44 PM)

Surface preparation and conditions for painting of concrete surfaces can be found in SSPC-SP13 or NACE No. 6. That's right: All new concretes can be coated after 28 days, but the humidity of concrete and also soundness must be considered.


Comment from Jack Henley, (2/14/2011, 11:59 AM)

To my knowledge, there is no one rule that applies to all concrete, the 28-day rule. That rule applies to destructive testing, the 28-day break. Beyond this, you will require a vast amount of information, plus a very good product and a notable procedure.


Comment from Robert Cox, (2/14/2011, 8:08 PM)

The 28 days is a standard for strength of concrete. Normally, design of concrete is based on a mixture of sand, rock, cement and admixtures necessary to support structure. Chosen admixtures can cause slower or faster drying time, ie, gain in strength to support structure. Coating concrete: 1. Read the mfr's instructions on the paint container. 2. Call testing laboratory to make field tests of moisture (still) in the concrete. 3. When the moisture and other requirements of the manufacturer for application have been achieved, then it's ready for paint. Note: If it is a large job, call the manufacturer to visit the project. Get the manufacturer involved. Get him to tell you that it's ready to paint.


Comment from Bill Patterson, (2/14/2011, 10:53 PM)

Theoretically, concrete is never "completely" cured or hydrated. Curing continues at an exponentially decaying rate indefinitely. As noted in other posts, the 28 days was chosen to provide a standard time for specifications and testing, since without a standardized cure time, the strength is a moving target. None of that helps answer the question as to when coatings can be applied, to which Robert Cox's answer is right on. Get technical expertise from the manufacturer. Not only does concrete vary in its properties, but coatings vary in theirs.


Comment from Robert Cox, (2/15/2011, 12:59 AM)

And another thing... Concrete form release agents remaining on the concrete surface may not be compatible with the chosen paint. When you are finishing architectural concrete, get the paint manufacturer out on the job to look at residue on concrete surfaces. Robert Cox


Comment from Glenn Summers, (2/16/2011, 7:54 AM)

Bill Patterson and other comments go to the root of the question. We want to maintain moisture in the matrix to allow for complete hydration. And yes, as Robert Cox says, any relaease or curing/evaporation retarders must be removed prior to a coating application. For years, we have been applying a penetrating concrete sealer that does not form a film or membrane on a surface. Application is made as soon as the heat of hydration is lost, promoting a slow internal cure [keeping the moisture inside] that deters shrinkage, creep and crazing. After this application, a paint/coating may be applied after 48 hours without fear of moisture or internal chemistry migrating out to a surface. This same surface will also accept any coating at some future date without sand blasting, grinding or acid etching as a surface prep step prior to coating. Once the new pour has been stabilized, it resists carbonation and contamination into the matrix. After 48 hours, the contractor controls when the concrete is coated! Compatibility and adhesion testing by various manufacturers demonstrates excellent test results and spread rates on treated concrete. Low VOC content allows for fast tracking and interiors being finished in record time.


Comment from david cuthbertson, (3/2/2011, 7:30 PM)

I agree that SSPC and NACE have more than adequate standards for concrete coating and linings, but also too would recommend that applicators adhere to Product TDS wherever practical. Some products are Moisture Tolerant and therefore have a slightly higher acceptance to contained moisture. In the end, it is up to the applicator to satisfy that all Process Controls are put into place, and strictly followed. Unlike Carbon Steel, all concretes are generally different in composition and should be approached with care.


Comment Join the Conversation:

Sign in to our community to add your comments.

Advertisements
 
SAFE Systems, Inc.
 
SAFE Systems'
Blast Lights &
Deadman Switches
 
Halogen or LED blast lights available with our NEW urethane bumper. Switches available in many colors for color coding your hoses.
 

 
Industrial Vacuum Equipment Corp.
 
Hurricane Vacuums
& Dust Collectors
 
Vacuum and dust collector hose, filters and related accessories.
IndustrialVacuum.com
 

 
Safway Services
 
Safeguard Assets. Ensure Productivity. HAKI®
 
Protect assets and equipment. Keep facilities open and operational. Maintain schedules regardless of weather. Ensure smooth and continuous production. Easy to erect. Safway is the primary distributor of HAKI® products including HAKISPAN and HAKITEC® 750 – in North America.
 

 
Strategic Materials Inc.
 
www.truabrasives.com
 
TruAbrasives™, a clean crushed glass abrasive superior to other abrasives for performance, health, and environmental benefits.
 

 
HoldTight Solutions Inc.
 
NO FLASH RUST - NO CONTAMINANTS
 
Our HoldTight®102 salt remover & flash rust
preventer prevents flash
rust by removing surface contaminants. Contact us
for your nearest distributor.
(800) 319.8802 sales@holdtight.com
 

 
Abrasives Inc.
 
Discover the MAGIC.
 
Black Magic® coal slag. It’s consistent, cleaner, cuts better, less dust. Get it where you need it, when you need it. Abrasives Inc. info@abrasivesinc.com
 

 
DeFelsko Corporation
 
PosiTector SST Soluble Salt Tester
 
Measures the concentration of soluble salts on metal surfaces. Use with all Bresle patch types including the reusable, adhesive-free PosiPatch.
 

 
W Abrasives
 
Unrivaled Expertise for your Surface Preparation
 
As the global leader in steel abrasives, W Abrasives material is the efficient and eco-friendly solution blasting with you to reach the perfect profile.
 

 
International WorkBoat Show
 
Power Forward
 
Join us Nov. 29 – Dec. 1 in New Orleans for the 2017 International WorkBoat Show. If it can power your business forward, you’ll find it here. Register Now!
 

 
Advanced Recycling Systems
 
Self-contained Vacuum Trailer
 
Stand alone or combine with ARS recyclers for longer vacuum retrievals!
Contact ARS at 330.536.8210 or visit www.arsrecycling.com.
 

 
 
 
 

Technology Publishing Co., 1501 Reedsdale Street, Suite 2008, Pittsburgh, PA 15233

TEL 1-412-431-8300  • FAX  1-412-431-5428  •  EMAIL webmaster@paintsquare.com


The Technology Publishing Network

Durability + Design PaintSquare the Journal of Protective Coatings & Linings Paint BidTracker

 
EXPLORE:      JPCL   |   PaintSquare News   |   Interact   |   Buying Guides   |   Webinars   |   Resources   |   Classifieds
REGISTER AND SUBSCRIBE:      Free PaintSquare Registration   |   Subscribe to JPCL   |   Subscribe to PaintSquare News
MORE:      About PaintSquare.com   |   Privacy policy   |   Terms & conditions   |   Site Map   |   Search   |   Contact Us