Applying a Coating: Preliminary Steps

Starting a Project? Preparing to Apply a Coating? Hold on!

Before diving in, there are a few crucial preliminary steps to follow to avoid unpleasant surprises! In this video, Jérémy Poupart, Technical Advisor at Beissier, walks you through the essential preparatory steps for coating application, tailored to different substrates. Our expert explains how to properly prepare a worksite and shares valuable tips on how to prime surfaces before applying coatings.

Key Steps Before Applying a Coating

Before beginning your project, and to ensure optimal adhesion and long-lasting finishes, it is essential to assess and identify your substrates. This involves checking their condition and type—whether they are fragile, concrete, fibre cement boards, or previously painted surfaces.

Your guiding principle: “The site must be watertight and airtight.”

In other words, before starting, make sure your surfaces are sound, dry, clean, and free of powdery residues (they should not have a chalky consistency).

In this video, our expert and technical advisor, Jérémy Poupart, explains how to properly prepare your worksite before applying a coating, according to the type of substrate.

Powdery Materials: Old Plaster, Plaster Tiles, and Aerated Concrete

These materials tend to be dusty and fragile. It is essential to apply a fixing and hardening primer to ensure proper adhesion. Otherwise, your coating may fail to adhere properly and could start blistering. (If your coating blisters, check out expert Raphaël Estrella’s advice in our video: “My Coating Blisters and Peels After Drying – What Should I Do?”).

For Concrete Surfaces

If you notice grease stains, wash them off. For rust, clean the surface and apply an anti-rust primer to the affected areas. In case of surface pitting, smooth out the substrate and refer to our video “Microbubbles: My Coating Forms Bubbles – What Should I Do?”

Additionally, check the porosity of the surface. If the concrete is too dense, the coating may struggle to adhere. Perform the water drop test to assess porosity: pour water onto the surface.

If the water is absorbed, the substrate is porous. Sand it and apply a universal primer to enhance adhesion.

If the water remains on the surface, the substrate is non-porous, meaning you can proceed without concern!

For Fiber Cement Boards

Before applying your coating, ensure proper alignment between the boards using a straightedge. If there is a gap, fill it with our Prestonett R filling compound. Also, inspect the joints: if there is excess adhesive, scrape it off.

Our expert recommends applying a primer to prevent incompatibility between the coating and the joint adhesive. The primer should be applied with a roller for better penetration. Additionally, check the depth of the screws and tighten them further if needed using a screwdriver.

For Previously Painted Surfaces

For satin-finished paint, clean, sand, and prime before applying the coating.

For matte paint, a primer alone will suffice.

Now you’re all set to begin your project! Always remember: a well-prepared worksite saves time in the long run!