Wall Render Guide

More About Render

Around 30% of the energy that is used to heat a home is lost through external walls, and rendering can help this

Render is a cladding option applied to the exterior of a home. It is applied to the exterior of a home. A lot like plaster is applied to the interior of your home. There are two main reasons that render is applied; one is that it will protect the underlying material from the elements, and the second is to provide an attractive appearance to your home. 

Many wonder what the difference between plaster and render is. The biggest difference is that plaster is applied to internal walls, and render to the external surface of your home. Render is made with cement, sand, and water. Lime may also be added to the mixture. 

Rendering also uses more cement than plastering, as this increases the strength of the walls and offers more protection.

Rendering the walls of your building may also make it more efficient. Around 30% of the energy that is used to heat a home is lost through external walls, and rendering can help this. You might want to take into account the money you could save over time when considering the cost of your render type. 

You don’t usually need to apply for planning permission for repairs and maintenance to render. However, you would need planning permission before completely changing the cladding of your home if you lived in a conservation area. 

Depending on where you are building your home, you may want to get in touch with the local council or authority to see what type of cladding is allowed before you make your decision.

The Types Of Render Available 

When silicone is used, an even longer life is promised and the capacity for the render to be self-cleaning is attractive to homeowners

When many people think of a render finish, they think of the old fashioned grey pebble dash post-war housing. However, there are so many more options to choose from these days. You can still go for that look if you wish, but there are many more colours and finishes. 

Below, we will talk about some of the types of render available and what they may be good for: 

• Acrylic - an acrylic render will usually be applied in a thin finish to seal and enhance the appearance of the underlying coat. They can add colour and texture to the finish, and fibres may be added to prevent cracking.
  
  This creates a durable and lasting finish. When silicone is used, an even longer life is promised and the capacity for the render to be self-cleaning is attractive to homeowners. Some say that when it rains, the added silicone allows rainwater to wash away dirt.
  
  This means that you may not need to spend so long or as often cleaning the render as with other types. 
  

• Monocouche - this is a French word meaning ‘single layer’ or ‘bed’ renders. These products originated in Europe. It is supplied in bags, and ready for mixing with water.
  
  You can apply it by hand trowel or spray it on. 
  

• Cement - cement renders are usually used as standard. They are mixed on site and usually applied in several coats, then painted when they are dry. Painting them regularly to ensure they remain looking good is important.
  
  The cement render is cheap in terms of material, but more expensive in labour because of the numerous coats. It does have a tendency to crack if the underlying structure moves, too. 
  

• Polymer - polymer renders are pre-mixed and pre-coloured. They are often through-coloured, with either white cement or lime as a base. 
  

• Lime - lime renders haven’t been used in decades but appear to be making a comeback. Lime is better than cement as it’s less likely to trap moisture in the brickwork, plus, it’s more visually appealing.
  
  However, it is more expensive than cement and even harder to apply. 
  

Can Renders Be Coloured? 

Grains within the render can create shadows, and this, in turn, can make the colour look very different from what it looked like when you selected it

You may redecorate your home with a coloured render if you want to refresh your property and give it a brand new look. Renders come in many colour options, so you should be able to create the finish that you really want on your home. 

Bear in mind that although you may like the colour of the render, the render itself may not be suitable for your property, so this is the first and most important consideration that you have to make.

Now, back to colour. Oftentimes, people don’t realise that their choice of grain size affects the way a house render colour looks once it is finished. Grains within the render can create shadows, and this, in turn, can make the colour look very different from what it looked like when you selected it. 

As a general rule, you should remember this: the larger the grain size, the darker the finished colour will look. If you want to keep the colour of your render looking as close as possible to what you saw on a sample piece, it should have a smaller grain size.

Pros and Cons Of Render Types

There are some pros and cons of various render types to be aware of before you make your final decision. Let’s take a look at those below. 

Lime Render Pros

• Breathable
  

• Flexible as a material
  

• Has numerous uses, both internal and external
  

• Can be used on various substrates 
  

• Has an attractive and traditional finish
  

• Is low maintenance 
  

• Tends to be long life
  

• An eco friendly option 
  

Lime Render Cons

• Soft
  

• Needs to be applied by a skilled professional
  

• Requires well graded washed aggregates
  

• Can be expensive 
  

Sand and Cement Render Pros

• Strong and hard
  

• Cheap
  

• Easy to apply
  

• Can be mixed off-site 
  

• Quick cure time 
  

Sand and Cement Render Cons

• Rigid and inflexible 
  

• Prone to cracks
  

• Wall has to be permanently dry
  

• Higher maintenance
  

• Not suitable below the damp course 
  

Clay Render Pros

• Environmentally friendly
  

• Is easy to rework and repair
  

• Cost-effective
  

• Local extraction is sometimes possible 
  

Clay Render Cons 

• Poor resistance to erosion
  

• Needs protection from driving rain
  

• Variability of performance 
  

Weather Considerations To Make

If you are building in a very rainy or wet area, you probably shouldn’t select a render that is prone to organic growth

There are weather considerations to make regarding your render. The ideal temperatures for installing your render can vary, especially between manufacturers. Many believe that the optimal temperature for applying renders should be between +5 and +25 degrees Celsius.

However, if the temperature does happen to be over 25. This does not necessarily have to put a stop to the work. There may be ways to work around hot/cold temperatures. 

It’s also a good idea to consider the location of your newly built property before selecting your render. If you are building in a very rainy or wet area, you probably shouldn’t select a render that is prone to organic growth, or you will often find yourself jet washing mould and other types of grime from the walls. 

Costs

Usually, the rendering process goes something like this:

• A sand and cement ‘scratch coat’ is applied
  

• A finer render topcoat is applied
  

• Two coats of external masonry paint are applied
  

This tends to cost anywhere from £40–£60 per m². By this sum, rendering and painting a typical three-bedroom semi-detached house with 80m² of walls would be £3,200–£5,200. 

For a bungalow, the price may be somewhere between £2,100-£3,000.

The actual cost of the render will depend on things like whether scaffold is needed and the number of days needed to complete the work, as well as the type of render you select. In some cases, it may take anywhere from a few days to a few weeks to complete your render. 

Standard cement render may not be so expensive, but lime render will bump up the cost substantially. All of these things must be considered when figuring out the price.

Maintenance of The Different Types 

Avoid using a harsh hose nozzle when you do come to wash down your render, as you don’t want to cause lasting damage

Here, we’ll talk about the maintenance required for different types of render. The amount you’re willing to spend on maintenance and the time needed should go into your decision of the render you select for the finish of your home. 

• Monocouche - taking care of this finish is crucial if you would like it to last for life. It is possible for it to last forever, but only if you’re committed to taking good care of it. A gentle pressure wash or hand wash is recommended once every 6-12 months, or when you notice that it is looking a little dirty.
  
  It’ll give it back it’s sparkling finish, and you’ll be able to avoid using more harsh cleaning chemicals later on down the line, which could break up the render and make things more expensive for you in the long run. When you have had this render initially installed, you should usually refrain from touching it for a minimum of 28 days, as everything needs to be cured and set.
  
  It’ll take around 28 days for this type of render to reach its optimum strength. Avoid using a harsh hose nozzle when you do come to wash down your render, as you don’t want to cause lasting damage. Always rinse off detergent as you go along so that it doesn’t cause any damage.
  
  Fungicidal wash can get rid of mould growth if you notice it, but this may not be necessary. You can apply this with a sponge, cloth or knapsack spray, then leave it to dry for 24 hours.
  

• Silicone - as this option is hydrophobic, it tends to resist organic growth such as mould, so you will often find that it needs very little maintenance for as long as you have it. It’s better to clean this option as and when you need to, as it probably won’t show much dirt at all.
  
  Never use acid cleaners as this will damage the render. If you want to paint over this at any point, using silicone paint is required. Silicone paint will extend the lifetime of your render, but make sure you give it a gentle wash and allow it to dry fully first.
  
  If organic growth does happen to appear, a fungicidal wash works best. 
  

• Acrylic render - grime and pollution tend to affect acrylic renders more, as they do not have the same hydrophobic properties as other render options. Because of this, they may look dirtier over time. If you live in a cold or wet area, you are likely to notice mould.
  
  The larger the grain size, the more chance you have of your render retaining dirt. A soft bristled brush can be used with warm water as well as a household detergent to clean your render. If it looks very dirty, a low-pressure jet wash will work.
  
  As a minimum, one gentle wash a year is a good idea. You may want to paint over the facade with silicone paint if you begin to notice heavy staining at any point. 
  

• Mineral render - the aftercare for this type of render varies slightly from the rest. After the mineral render has been applied, it must be painted with silicone paint so that lime bloom can be prevented. If the render is subjected to damp conditions and paint is not applied, lime bloom will appear.
  
  The silicone paint will help to seal the render against the elements, giving it a tougher finish and protective layer. Lime bloom is very difficult to get rid of once it has appeared, even with the cleaners that are available on the market to get rid of it. Because of this, you should always use a silicone paint on your mineral render. Signs of lime bloom include lightning and patchiness.
  
  Providing you apply silicone paint, lime bloom will not be a problem for you and maintenance will then be the same as silicone render. Simply remove dirt with a gentle jet wash and soapy water. If you want to refresh this, later on, you can apply silicone paint to give it another protective layer and a fresh finish. 
  

• Pebbledash - this is supposed to be an extremely hard wearing finish, but there are still problems that can cause things like mould growth. Removing any organic growth with a brush and water is a good idea, but scrubbing too hard will cause stones to fall off, so do be careful.
  
  Spray the rest with the EWI-360 Fungicidal Wash and leave it on for 24 hours afterwards. There shouldn’t be any growth left after this, but if there is, the brush and water should get rid of what’s left. Over time, the stones on pebbledash may fall off naturally. This is just due to weathering, but it can affect the overall look of your property. The lack of stones will also leave the render susceptible to bad weather.
  
  You can’t repair pebbledash in patches, and painting over it will likely make it look worse. If you want the old look back, you will have to have it re-rendered. You may want to replace it with coloured render. 
  

A Guide To Wall Render For Houses: Conclusion

The type of render you select for your property will depend entirely on how much protection you think you will need, the maintenance you’re willing to put in overtime, the finished look you want, and a variety of other factors. 

You’ll need to weigh up your needs and the pros and cons of each option fully before making your final decision. The wrong decision could mean ending up with a look that is very different to what you were expecting, with a darker colour and maybe even a lot of organic growth if you live in a cold, wet location.

If you’re still unsure as to what type of render to select after reading this guide, it’s a good idea to talk to a professional with experience who will be able to help you select the right one. The right renders for your home will protect it from all of the elements, last a long time, look great, and suit your lifestyle perfectly. 

Your render isn’t something you should cut corners on, so use the advice here to get the very best finish!