How To Apply Rendering To External Walls

If you're keen on DIY and decorating, you might want to consider applying rendering to your home's external walls. Cement render provides protection from environmental elements, insulates your home, improves fire resistance and can be very aesthetically pleasing too.

Here's a quick guide on how to apply rendering to your external walls.  

Preparing the surface

Before you can apply rendering to your walls, you will need to clean off any dirt, oil, paint or grease that could prevent the render from adhering properly.

For slippery surfaces, such as metal window frames you will need to apply a very strong mix of cement and water, applied to the surface and allowed to dry before rendering. This 'dash' coat ensures that the render will stick to the surface.

If your walls are made of a very absorbent material, such as sandstone, you'll need to soak them with water so that the newly applied rendering does not become parched.

Preparing the render

Render can be bought from DIY and building suppliers, ready to mix and in various colours and finishes.

Start by combining the dry ingredients so that the colour is uniform. Gradually add water to the mix, until a putty-like consistency is achieved. You can mix the render on a flat surface, in a wheelbarrow, or in a mini cement mixer. Always choose a cool day to carry out rendering work so that the material does not dry out as you work. For the same reason, only make up enough render to last you for 45 minutes or so.

How to apply the render

To make sure that the render is of equal thickness, nail wooden battens vertically to the wall. This also provides a clean edge.

Use a steel float to apply the first layer of render. Keep applying the render in layers until the desired thickness is reached. Use a straight edge to level-out the render between each layer.

If you need to apply a second coat of render, you must allow the first coat to dry out completely before applying the next. You will need to 'scour' the first coat with a wire brush so give the next coat of render something to adhere to.

The above brief overview gives you an idea of what to expect if you decide to take on a rendering job yourself. If you're not confident that you can successfully complete the task, it may be best to hire local painters to do the job for you.

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