How to Repair Concrete

If mortars fail, it is often due to a breakdown of cohesion in the substrate near the bond line. Coating failures, on the other hand, appear as localised or widespread debonding, especially when contaminants have been left on the surface. The solution is to carry out effective substrate preparation.

Medium to heavy texturing of the substrate is the secret to ensuring the best adhesion of mortars. While coatings can do without a textured surface, a touch of light texturing enhances their grip and ensures longevity.

Now that we’ve established the importance of preparation, let’s dive into the tools and methods that make it happen:

• Open Grit Blasting: This method is the go-to for prepping concrete surfaces before repair and coating work. Adjust the grit grade to achieve the desired texture. Grit blasting also works on steel reinforcement.

• Pressure Washing: Ideal for removing surface contaminants or creating a lightly textured surface, pressure washing is a versatile method in concrete repair prep.

• Hydro Demolition: Using high water pressure to remove sections of reinforced concrete, a prelude to replacement or modification works.

• Concrete Breaking: Breakers can be used for removing concrete before patch repairs. Handle with care to avoid unintended fractures in the remaining concrete.

• Scabbling: For surfaces needing more texture than blasting can provide, single-headed or three-headed scabblers can be used for concrete surface preparation or targeted removal in patch repairs.

• Needle Gunning: Needle gunning is excellent for localised coating removal or achieving a lighter texture compared to scabbling.