Rendering
Rendering is a great way of changing the look and texture of your external walls as a longer-lasting alternative to paint.
Essentially, rendering is applying a mixture of wet cement and sand to an external wall with a trowel. 

As straightforward as that sounds, there is an art to it which requires practice. 

It is best to practice on a garden or garage wall before attempting the external walls of your home.

Preparation preparation preparation

As with most construction projects, preparation is key. 

First check the weather! You need a couple of good dry days to do this job as it will be annoying to watch your render wash off the wall in the rain as it hadn’t had time to dry properly. 

The wall then needs to be prepared before render can be applied so remove any old render, paint or mortar with a chisel. 

Then scrub the wall with a stiff bristled broom to remove surface dirt, moss and mould.  

Finally, hose the wall down with water to remove any loose debris. 

The wall is now ready to render and you can start whilst it is wet as long as water is not pouring down the wall. 

Getting stuck in 

Before getting stuck in with the render, lay some cloths down at the base of the wall. Any dripping render will go onto the cloth rather than hardening on the ground which will look unsightly and cause you a whole lot of grief having to chip it off.

You need to choose the most suitable render for the job in hand, and you will be required to mix it to a spreadable consistency. 

Always follow the instructions on the packaging or ask staff at Amaroc for guidance on this. 

When the render is mixed correctly it should have a thick paste-like consistency. 

It’s important to wipe render off any tools you have used to mix it before it hardens. 

The key to applying the render to the wall is steady, even strokes placing the render on the trowel against the wall and sweeping upwards. 

The first coat should be as even as possible with a thickness of approximately 5mm. Then a straight edge should be dragged upwards along the wall, evening out this first coat and ensuring a smooth surface.  

Before this coat has hardened take a scratching comb and score the surface. This will create depressions making the second coat adhere more evenly.

Now wait for two hours or so for the first coat to have firmly adhered to the wall. 

The second coat of render should be 10mm thick and is applied in the same way as the first coat with smooth upwards strokes. 

Then instead of scratching the surface with a comb, smooth the second coat with a wet sponge. 

Leave to dry for 24 hours. Spray the wall with water each day for five days to prevent the render drying too quickly and cracking.

After five days the render should be completely dry and should last for a fair few years. 
August 07, 2019 by Amaroc Collaborator