How to render over brick

Start by assessing the condition of your brick wall and deciding on the best approach. If the mortar joints are deeper than a few millimetres or the surface is uneven, a multipurpose render is a good option as it helps level things out and create a consistent base for your brick wall repair. If the wall is already relatively smooth, you might consider using a finer finishing render instead. For walls that have previously been painted or sealed, applying a bonding agent beforehand can help improve adhesion and ensure a better result.

A clean, sound surface is key to a successful render. If you’ve used a pressure washer to clean the wall, allow a few days for it to fully dry before continuing. Once dry, go over the entire surface with a stiff bristle broom to remove any dust, dirt or loose material. If you come across any damaged bricks or crumbling mortar, it’s worth repairing these areas first to ensure the render has a solid base to adhere to. It’s also a good idea to check the product instructions to confirm the surface preparation requirements for optimal house rendering results.

If the bricks are dry and porous, lightly dampen the surface using a fine mist of water. This helps prevent the render from drying too quickly, which can lead to cracking or poor adhesion. The goal is to have a slightly damp surface, not one that is wet or dripping, so take care to apply an even, light mist.

Begin by adding clean water to a bucket, then gradually introduce the render while mixing with a drill and paddle. For the ideal render mix ratio continue mixing until you achieve a smooth, creamy consistency with no lumps. Let the mixture stand for a few minutes before giving it a final mix. Different products can vary slightly, so it’s important to follow the recommended ratios and working times on the packaging.

Using a hawk and steel trowel, apply the render to the wall in small, manageable sections. Spread it evenly across the surface, aiming for a consistent thickness and building up areas where needed to even things out. There’s no need to screed the surface, so focus on keeping your trowel work smooth and consistent as you go. Holding the trowel at a slight angle will help achieve a more even render finish. If you notice the render starting to drag or stiffen during application, it may be beginning to set, so it’s best to stop and mix a fresh batch rather than trying to rework it

Once applied, allow the render to firm up slightly before finishing. This typically takes between 10 and 30 minutes, depending on the weather conditions. In warmer or windy environments, the render may set more quickly, so it’s important to keep an eye on the surface and adjust your timing as needed.

When the render has firmed up, you can begin finishing the surface to achieve your desired look. A float can be used to create a smooth, dense finish, while a damp sponge will give a more textured effect. Work evenly across the wall to maintain consistency, and lightly dampen the surface if needed to keep it workable. This is also the stage where you can refine any minor imperfections, such as trowel lines or uneven patches.

If a second coat is required, it can be applied once the first coat has dried, usually after 6 to 8 hours. Applying a thinner top coat can help achieve a more refined and uniform finish, particularly if you're aiming for a smoother look

Allow the render to dry and cure properly before applying any paint or additional coatings. While it may feel touch dry in around 1 to 2 hours, a full cure takes longer. As a general guide, allow at least one day of curing for every 2 millimetres of thickness. In hot or dry conditions, lightly misting the surface during curing can help prevent it from drying too quickly and reduce the risk of cracking.

Finished rendering your brick wall and looking for more exciting projects for your brick wall? Take a look at our article on how to install masonry fixings.