...For A Perfect Finish
Preparing Concrete For Painting
August 15, 2019
Preparing Old, Bare concrete surfaces.
Interior and exterior concrete surfaces do not have to remain a flat, boring shade of gray. Concrete can be made to look interesting and beautiful by applying a few coats of paint. Painting concrete is a simple and inexpensive task that can be completed by most homeowners. In order to successfully paint concrete it is important to clean and prep the area properly, apply an appropriate concrete paint, and allow adequate time in between each step to ensure that the end result is perfect and long lasting.
Below is a short step by step on how to properly prepare old and bare concrete before painting using Nutech EcoSafe Concrete preparation products.
Prior to commencing, assess the concrete surface for surface contamination and identify areas to be sealed which will require thorough cleaning.
Assess the area to be sealed for surface porosity, cracks and structural issues.
Where required, consult an engineer for further advice.
Step 1: Cleaning the surface
Grease and oil removal.
First, sweep away any surface leaves, debris, and dirt. Then remove any existing paint or gunk using a power washer or scraper and wire brush.
• Where required, clean residual grease and oil using Nu-EcoSafe Degreaser.
• Mix 1 part Nu-EcoSafe Degreaser to 4 parts water.
• Apply by plastic watering can or pump spray pack, liberally to the soiled area.
• Allow the solution to activate on the surface for at least 5 minutes. Multiple treatments may be required.
• High pressure clean with a recommended minimum water pressure of 2000 psi.
For stubborn grease and oil stains, a second undiluted application of Nu-EcoSafe Degreaser may be required.
Step 2: Moss and lichen removal
Moss and lichen removal (where applicable)
• Remove all loose contaminants including moss build up, dust, dirt and debris.
• Mix Nutech Hypo based on level of contamination;
– Lightly Soiled Areas: Mix 1 to 1 with clean fresh water.
– Heavily Soiled Areas: Neat – no dilution required.
• Apply liberally to affected areas via watering can or pump spray pack.
• Allow Nutech Hypo to activate on the surface for a minimum of 2 hours.
• High pressure clean with a recommended minimum water pressure of 2000 psi.
• Allow the concrete surface to dry thoroughly.
If badly affected by Moss or Lichen treat with Nutech Hypo prior to pressure cleaning.
Step 3: Etching old bare concrete
Note: PaveCoat MUST penetrate the surface to achieve good adhesion. It is imperative that the concrete surface is etched prior to application to improve porosity and sealer absorption. Etching is often a pre-requisite for application of high-performance paint/coating systems.
- DO NOT Etch if the concrete is powdery or soft. Further surface treatment may be required. Please contact Nutech Paint for further advice.
Step 4: Mixing the Etc
Use a plastic watering can to mix and apply the etch as outlined;
• Rough stipple finished concrete:
1 part Nu-EcoSafe Etch or Nu-EcoSafe UltraEtch to 15 parts clean water.
• Smooth steel trowelled concrete surfaces:1 part Nu-EcoSafe Etch or Nu-EcoSafe UltraEtch to 10 parts clean water.
• Hardened or High MPa Concrete:
1 part Nu-EcoSafe Etch or Nu-EcoSafe UltraEtch to 5 parts clean water.
When mixing Nu-EcoSafe Etch or Nu-EcoSafe UltraEtch, always add the etch in the recommended ratio to water.
Step 5: Applying the Etch
Use the watering can to evenly wet the entire concrete surface with diluted Nu-EcoSafe Etch or Nu-EcoSafe UltraEtch solution and allow to activate on the surface for 15 minutes.
• After 15 minutes, high pressure clean with a recommended minimum water pressure of 2000 psi.
• Allow the concrete surface to dry thoroughly.
Step 6: Test for porosity and moisture content:
Determine porosity.
• Measure 1 cup of fresh water and pour onto the dry surface.
• Observe water absorption noting absorption within 30 seconds.
• If water pools or is slow to be absorbed, a second application of etch will be required.
• Repeat etch process if necessary.
Step 7: Determine moisture content:
The concrete should have less than 5% moisture content prior to sealing.
• A calibrated moisture test meter should be used to assess the percentage of moisture present prior to application.
If there is no access to a moisture test meter, tape a plastic sheet onto the concrete surface and leave for 30 minutes. After 30 minutes, lift the plastic sheet. If no moisture or condensation is present under the sheet, the concrete is dry enough to apply the sealer.
Your Concrete surface is now ready to paint!
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