damaged render

Repairing and Maintaining Render

9 November 2021

Repairing cracks in render is one maintenance job that needs to be carried out to protect your property from the external elements that could penetrate their way through into the house. The external walls are the forefront of a property, which means the walls are not only structural integral to keeping the building standing, but also provide protection against weathering, structural defects and much more.

Having a well-constructed property that is properly maintained will ensure that the interior of the house will be warm, dry and comfortable to live in. It is important as a homeowner to be aware of any problems and make sure these are rectified as soon as possible. This will also involve rendering repair work and maintaining the brickwork.

Do I Have Solid or Cavity Walls?

The first consideration to understanding your building is to know the construction of the building. Understanding the type of building means you will be able to understand the potential defects you could be faced with but also what type of wall repairs will be needed to fix any problems you may encounter.

The majority of the houses are constructed with cavity walls; however, traditional solid brick walls were constructed before the 1930s.

What is House Rendering?

To protect the exterior of a house then a lime based wall coating is applied to the walls. This protects your house from problems such as weathering and erosion.

What Causes Render Cracking?

As we have already mentioned, the external walls are the biggest form of protection a building can have so it is important that if there are problems with the render then having rendering repairs carried out has to be the number one priority. If the render is not regularly maintained, then serious issues can start to develop.

Cracks in the render can happen over time. If the wall behind the render starts to move, then this will mean the render will move too. One of the main causes of this is structural movement.

One of the common causes of render cracking and bulging is moisture in the frost getting trapped in between the render and the wall. When there are small cracks in the render these should be sealed as quickly as possible.

If the small cracks in the render are not sealed, then this will allow the moisture that has penetrated its way through to freeze within the render and expand.

Once this expansion occurs then the small cracks can eventually become large cracks which then puts the structural integrity of the building at risk.

There can also be the case of sections of render missing which can be as a result of physical damage. If the moisture is trapped behind the surface, then it will penetrate through the walls creating ideal conditions for wood rot to occur.

How Are Render Repairs Carried Out?

The modern practice of repairing render usually involves two coats of render that are usually applied onto the surface of the wall. The strength of the coat being applied will depend on the type of building construction it is being applied to e.g. brick or stone.

In the majority of cases, the whole of render will not need to be replaced but only in localised sections. The contractor will first remove any cracking or hollow render. These patches of the wall will then be exposed so they will need time to dry out before the new coats of render can be applied.

How Does Brick and Stone Become Damaged?


When you own an old period property and it is ageing this can be seen as a good thing, however, this could also be a sign of the problems to come.

Having minor erosion for old brickwork or stone is a common occurrence and it is not a problem when it only impacts certain areas of the exterior wall. However, when you should be concerned is when the erosion is more severe and damaged masonry needs to be repaired or even replaced.

If brickwork looks like it is crumbling or there are white salts on the surface, then this is where there you might have problems. The normal rule of thumb is that unless the erosion of the brickwork is causing damage then no repair will need to be carried out.

If there is serious damage from erosion, then this can lead to the possibility of penetrating damp or the structural integrity of the wall. The common reason for having damaged bricks occurs when damp has become trapped within the bricks freezes then it expands therefore causing the surface bricks to deteriorate.

How to Repair Brickwork?

Now we have explained the reasons why brick and stonework can become damaged, how can it be repaired? If the brick or stone walls have crumbled, then there is a possibility that this should be cut out and then replaced.

In some cases, if the brick or stone walls are severely damaged then these might have to be rebuilt to match the rest of the brick or stone of the property. If previous repairs to the old walls have been carried out using cement, then this could have resulted in the damp speeding up the erosion process. Lime mortar or breathable paints should be used instead to stop this from happening again.

What Can We Do to Help?

We hope this article has provided you with a better understanding of what rendering is, why rendering is needed and what can be done to repair it.

We have qualified technicians able to carry out render repair work and make sure your property is protected from any potential damp problems that could cause damage to your home. You can simply get in touch with us by calling 0800 288 8660 or contacting us online.