What You Need to Know About Weber Render

Rendering is a great way to add durability and boost the appearance of a building. If you are ready to render your home or workplace and want to explore all available options, this article on Weber render will help you to make the right decision for your project. Here, we have put together a guide on everything you need to know about using Weber render.

What is a Weber render?

Weber UK is part of a wider company called Saint-Gobain, which owns other construction brands including British Gypsum, Norton and Isover. Weber creates various renders and finishes to fit in with your project goals.

Advantages of using Weber render

There are many benefits of using Weber render. Here are the main advantages of Weber materials. 

1. Coloured render

You can choose different Weber render colours for your project. Whether you are working on an external wall insulation system or a decorative finish, you can choose a particular colour from the Weber render colour charts. Choices include cream, chalk, ivory and silver pearl. 

2. Quick application

Most Weber products - such as the Weber one coat base render - are quicker to apply compared to other renders including silicone. This will depend on weather conditions and temperatures, but the quicker process means reduced labour costs and scaffolding. 

3. Low maintenance

Weber render is generally low maintenance. If the render has been applied without any issues, a simple wash from time to time will keep the render looking fresh. 

Disadvantages of using Weber render

Despite the clear advantages, Weber rendering also comes with potential issues. Most likely, if the render has been applied correctly, you will not face any problems. But it is worth keeping the disadvantages in the back of your mind. 

Texture and colour issues

Particularly when you have to work in wet conditions, rainwater that lands on newly applied render is a problem. It can greatly affect the texture consistency and colour of the render, causing it to fade. In addition to this, a large amount of water can affect the adhesion between render coats. 

Lime bloom

It can be caused by low temperatures and damp conditions. This is because the cement is struggling with the slower drying conditions. Although lime bloom does not affect the durability and strength of a render, it can produce an unsightly white film to build up on the surface. 

Top coat protection

It is important to protect the render top coat as much as possible because it relies on evaporation to set and create a durable finish. If you have to work in low temperatures, be aware that the coat can be washed off before it has an opportunity to set. 

3 top tips on how to apply Weber render mix

It is not always possible to avoid rendering work in cold temperatures. But if you do have to complete a rendering job in the winter months, be sure to follow these top tips. 

1. Zero frost

Frosty conditions with render are never a good combination. It is important to keep note of the weather conditions - not only for when the render is applied but also for the dry and curing process. For any reason you have to work in frosty conditions, consider using heaters to increase the temperature and enclose any scaffolding. 

2. Use an accelerator

Using an accelerator - such as the Weber monocouche accelerator - can help to progress the initial set time. If the accelerator is used correctly, it can also decrease the chances of lime bloom forming on the render surfaces. An accelerator is particularly useful if you are applying Weber Pral M (Weber chalk render) or Webertherm M1. 

3. Support the substrate

If the substrate is exposed to wet weather conditions, it is potentially at risk of movement as a result of drying shrinkage. Movement can cause the substrate to crack, which can lead the render to also crack. The best way to protect the substrate from rainfall is to tent the scaffolding - you can use anything from tarpaulin to polythene and close mesh netting. 

Silicone renders vs monocouche render systems

A key consideration to think about before choosing a render is whether a Weber silicone render or one-coat render (monocouche) is right for you. Here, we have outlined the benefits and downsides of each one to help you decide.

Benefits of Weber silicone render

1. Breathable - silicone render is very breathable, which is good for helping the moisture which can build up behind the substrate to escape. A render that is not breathable could cause issues to the render and walls. 
2. Water-resistant - applying a water-resistant render is particularly important for durability and avoiding major problems such as dampness and wall corrosion. 
3. Flexibility - because a building can shrink in winter and swell in summer, silicone render will flexibly move to correspond with the weather conditions. This is a superior choice to a cement render which can easily crack. 

Downsides of Weber silicone render

1. Cost - silicone render can prove more costly compared to other render types such as cement or sand. The cost difference is predicted to be 10-15% more expensive than monocouche render. Its flexibility and durability are the reasons for its cost.  
2. Labour time - because silicone render needs to be applied in several stages, the labour time is considerably longer in comparison to other types. Also, depending on what the weather is like, the whole process can take an estimated 4 days to complete. Evidently, this is also a contributing factor to the high cost. 
3. Not eco-friendly - it is thought that mineral-based renders are less harmful to the environment compared to silicone renders, 10% less harmful to global warming and 30% less harmful to water environments. 

Benefits of Weber monocouche render

1. Easy to apply - you can apply monocouche render either by hand or with a machine, which can save you money and time. 
2. Durable - it is low maintenance, strong and does not need to be painted because it is a ‘through-coloured’ render. 
3. Flexible finish - depending on personal preference, the finish can either be sprayed roughcast to achieve a traditional appearance or scraped finished for a modern look. 
4. One coat - although it is applied in two applications, they bond together to create a stronger coat compared to its traditional counterpart. The finished thickness is approximately between 15-25mm. 

Downsides of Weber monocouche render

1. Less water resistance - although Weber monocouche render is considered to be water-resistant, it is not completely hydrophobic. It is known as microporous which balances the thermal pressure as a wall cools down or heats up. However, moisture can travel through the render, causing discolouration and generating algae. 
2. Difficult to patch - it is possible to patch up the render, but it does come with a few challenges because it is through-coloured. Particularly if bold colours have been used, if you need to patch up a damaged area, it is difficult to achieve an exact colour match. Once patching is complete, you may need to apply a thin render coat on the whole wall to achieve an even tone.
3. Prone to hairline cracks - all renders are at risk of cracking, but Weber monocouche render can produce hairline cracks. They are not very noticeable, but they still affect the appearance of a finished render. Moisture can also enter the cracks and cause damage to the render’s durability. 

How long does Weber render last?

Proper maintenance and cleaning will mean your render could last for approximately 20 years. Generally, render is low maintenance. But problems can still arise, such as graffiti or a build-up of algae. Here is how to protect your Weber render to maintain a fresh appearance.

1. Use Weberend Protect

To be used as either a spray or with a brush or roller, Weberend Protect is particularly effective for high-textured surfaces. It should be applied from the bottom to the top, making sure the product does not run - 1-3 applications within 10 minutes of one another should be applied for the best result. Each coat needs to be wet for a new application. To calculate how many coats you will need, use Weberend Protect on a small corner of the substrate first. Once a surface is completely dry, do not reapply Weberend Protect - this will cause some adhesion to be lost. 

2. Fix the cracks

Before you go ahead and use Weberend Protect on the surface, it is important to fix any small cracks that have appeared first. It will prove challenging to find an exact colour match to the existing render. However, cracks can be rectified to mirror the texture of the render. 

• Clean the particular area with Weber CL150 with a sprayer or brush, and leave the render for 2 days. This kills any algae - use a pressure washer after the 2 days. 
• You should then open the crack with a mini disc cutter. Run through the crack to make its width bigger. 
• Mix Weber Monocouche Accelerator with Weber Pral M - you should keep the dose at 100ml per 25kg bag. With 2 parts of clean water and 1 part of waterproof external grade PVA, mix everything together to produce a good consistency. 
• Now it is time to fill in the cracks. Fill a cartridge gun with the mixture of products and apply a small amount of it into the render crack. Be sure that the mixture is not overlapping the existing render. Create a protruding nib of approximately 2-3mm slightly above the existing render.
• You should let the material dry for around 20-40 minutes and remove the nib with a filling knife. If you let the material dry for more than 40 minutes, you run the risk of it turning into a much lighter shade.
• After the drying time, if there is a noticeable colour difference between the repaired crack and the existing render, you should consider using mineral paint. An example would be to use Webersil P, which is available to buy in more than 100 colours and two coats should be applied: the first with a 10-15% mix of clean water; and the second without water will need to be applied after 24 hours. Use a criss-cross pattern to achieve an even texture. 

How to clean Weber render

Once the Weber render has been applied, it is important to know how to maintain it to avoid any unnecessary issues in the future. This includes learning how to clean the Weber render - keeping on top of the cleaning will help it to last as long as possible. 

1. Prepare equipment

Use a brush to sweep away any moss or algae on the affected area. For an effective clean, be sure to use a Weber CL150 cleaner. It is advised to wear protective goggles and gloves when using this cleaner. 

2. Apply the cleaner

When you apply the cleaner, the wall should be completely dry. Start at the base of the render and work vertically. Even if any algae or moss has not appeared, it is worth using a cleaner on the render from time to time - in the long term, it will slow down the build-up of algae or moss.

3. Wash the render

After a minimum of 48 hours, you can use a mild detergent with a pressure washer to go over the render. Be sure to use a fan instead of a jet action as this could cause damage to the render. For the best results, you should consider washing the render once a year.  

Where to buy your Weber render materials with confidence 

Weber render materials are available to buy at Building Materials Nationwide with quick UK delivery options. If you would like to render your home or workplace, we can provide the best materials such as ready-mix render bags that deliver high-quality finishes. Speak to our friendly and knowledgeable team for advice on your rendering project. 

Construction and building industry customers will benefit from signing up for a trade account with us. In addition to being assigned a personal trade account manager, you can also set up a flexible credit limit or pay for your materials and tools with cash. Your trade account manager can organise deliveries and find everything you need at competitive trade prices - saving you time and money. Call us to learn more or sign up on our website.