External Rendering Rules: The Exception
Rendering the external walls of your home can protect your brickwork from weather erosion and ensures costly repairs are needed less often. There are a number of rules that must be followed when applying external rendering. 

The exception to the rules of external rendering concerns old properties; pre-war, Victorian or even older. This is due to the way the homes were constructed with the majority of them not having any form of damp-proofing in the initial structure. 

The objective of applying external render is to protect the walls from rainwater getting into the brickwork which could essentially destabilise the entire structure. 

With older properties, if using cement-based renders, whilst keeping rainwater out, the walls will not be able to breathe and with no damp-proofing, you will essentially be trapping water in the brickwork. 

However, all is not lost. 

To counter this problem, when dealing with pre-war and older properties, a lime-based render will be needed rather than a cement one. This will protect the external wall from absorbing atmospheric moisture whilst at the same time allowing the brickwork to breathe. 

When the wrong render has been used on the external walls, it is not the render that usually cracks and falls off. Instead, it is the internal plaster which is no longer able to adhere to the damp walls and will start to bubble and crumble.  

If the wrong render has been applied, it is advisable to get a specialist in to remove it as chiselling the cement render could end up damaging the bricks beneath which, as they are older, maybe fragile. 

For all your rendering materials and tools contact the experienced staff at Amaroc and we will be happy to help. 

We have a wide selection of renders including natural lime renders and we are happy to advise on what would be best for your specific job in hand. 
September 24, 2019 — Amaroc Collaborator