Blog

We have briefly mentioned in previous blog articles some of the benefits and reasons you might want use an external render system, but it is worth further elaborating on these points and more as to why rendering an external wall is beneficial to a property.

Improve the external appearance of a property

There’s no denying that applying a render system to an old, tired-looking building will transform its appearance – making it look modern and more visually appealing.  Local authorities will often use render when renovating their properties for this reason.

This aesthetic improvement can be beneficial in multiple ways – if you live in the property - it makes your home look nice. If you looking at selling a property, it can make it look more visually appealing to potential buyers. 

From a wide range of colours, to a huge selection of textures and finishes, there are a wealth of possibilities available when rendering a house.

Increase the thermal efficiency of walls

Some renders – like the K Rend Silicone Thin Coat range – can be used as part of an External Wall Insulation System. While most render systems themselves are not classed as insulating (though they do provide a small amount of innate insulation), when used as part of an EWI system they can help increase the thermal efficiency of walls and reduce heating bills – not to mention the other benefits featured in this article.

Weatherproofing

External walls that are in a poor condition can lead to the ingress of water and external debris which will worsen if left untreated. The use of a render system on an external wall forming a barrier, protecting a building from the elements. These renders incorporate water repellent technology, protecting against water whilst still allowing the substrate to breathe.

One of the biggest advantages of coloured external render is that it improves the appearance of a property while also helping protect the external walls from the weather. Modern coloured render systems are available in a wide range of textures and finishes, giving both homeowners and developers far more choice than traditional painted surfaces.

Many modern silicone render systems also offer improved flexibility and water resistance, helping reduce maintenance and keeping the finish looking cleaner for longer.

If you need help with applying render or you would like to know more about the benefits of render, contact our experts today.

Render systems are available in all sorts of colours, styles, finishes and textures and whilst they all vastly improve the appearance of a building, their suitability and appropriateness vary from factors such as the building substrate to planning regulations of the local authority.

What types of render texture finishes are possible?

Each manufacturer has renders with different finishes, and the look you wish to achieve will influence the render system used.

Textured, Smooth, Scraped and even more unique finishes such as brick effects or ashlar detailing are achieved via a combination of the application method and the finishing tool used.

How are different texture finishes achieved?

Standard renders usually have 3 categories of finishes - scraped, smoothed and textured – each with their own subtle variances. For example, Parex Monorex can be scraped to achieve a fine or medium finish. 

Scraped texture finishes are achieved by scraping the render with a scraping tool before the render has set hard whereas using a trowel or float will result in a smooth-looking finish.

Applying the render using a spray machine will give a far more pronounced texture finish, similar to tyrolean and roughcast.

There are also more technical and specialist finishes such as pebble dash where an aggregate is thrown onto a wet receiver; and brick or ashlar effects, where a pattern is cut into wet render to give it the appearance of real brickwork. 

Guidance on choosing the best texture finish

For advice on achieving the right texture finish, or if you would like guidance on choosing a texture finish, contact our experts who are always ready to help.

One thing I’ve learned over the years is that most rendering problems don’t usually come from the material itself. More often than not, they come from poor preparation, rushing the job or ignoring manufacturer guidelines.

Every render product is designed to work a certain way, and that includes everything from water ratios and application thickness to scraping times and weather conditions. Trying to cut corners or “do it your own way” can quickly lead to cracking, poor finish quality, colour inconsistency and unhappy customers.

This is especially true with monocouche render systems.

Modern monocouche render products are designed to provide a durable, through-coloured finish, but they still rely on correct application methods to perform properly long term. Even experienced renderers can run into problems if the conditions aren’t right or the guidance isn’t followed closely enough.

One of the biggest mistakes is assuming every wall will behave the same. Suction levels, background condition, temperature, wind and direct sunlight can all affect how render cures and firms up on the wall. A setup that worked perfectly one week can behave completely differently the next.

Water content is another major factor. Adding too much water might make the material feel easier to work with initially, but it can weaken the finish, affect colour consistency and increase the risk of shrinkage or cracking later on.

Timing is just as important.

With monocouche render systems, ruling off and scraping too early or too late can completely change the final appearance. Scraping before the material is ready can drag the surface and expose inconsistencies underneath, while leaving it too long can make the render difficult to work and affect the texture across the elevation.

Weather conditions also need to be taken seriously. Applying render during freezing temperatures, heavy rain or strong direct sunlight can create all sorts of avoidable problems. Even high-quality materials can struggle if they’re being applied outside the recommended conditions.

The same applies when using spray on render equipment. Machine application can massively improve speed and consistency, but only when the setup, mix and timing are all correct. Spraying material onto a poorly prepared background or in unsuitable conditions will still lead to problems no matter how quickly the wall goes on.

Preparation matters just as much as application too. Correct use of primers, beads and render base coat materials helps create a more stable system and improves the overall finish quality.

At the end of the day, manufacturer guidelines are there for a reason. They’re based on testing, experience and understanding how the system is designed to perform. Ignoring them might save time in the short term, but it often creates bigger issues further down the line.

A good renderer doesn’t just know how to get material on the wall. They know how to read conditions, prepare properly and work with the system rather than against it.

Use an Expert for Expert Results

Our qualified technicians are experts in applying K Rend and can help rectify any mistakes or issues that occurred during a previous poor application. Contact us today for help and advice on k rend application.

As we have written about before, large cracks in render can be an indication of a major problem in the substrate. However, smaller and much less serious fissures can also appear. These fissures tend to be a lot smaller than cracks (around 0.1-3mm in width) 

Origins of fissures in render

Like cracks, fissures can occur due to movement from the building or the substrate the render has been applied to. Whereas large cracks tend to be an indication of a more severe issue, minor fissures usually occur due to minor inconsequential movement in the substrate.

What to do if you find fissures in render

It goes without saying, but you should always seek the advice of a professional before attempting any repairs. Determining the origin of the fissure is essential to ensure that there are no recurring instances of the problem. It is also advisable to wait for a period of at least 6 months to make sure that all fissures in the render system have stabilised.

Repairing fissures in render

Our patented Mendrend Flexible Fissure repair system is specifically designed to repair fissures in render from leading manufacturers and is supplied in a range of colours intended to match render manufacturer colour ranges. We also provide a comprehensive support service for this product. 

Rendit offers expert help and advice on repairing fissures in render – contact us today to find out more

One thing some applicators are better at than others is providing their customers with sample test panels of a finished render product as it can cause big problems with customers who are expecting their render to look exactly like it does in the brochure or even worse on their computer monitors!

The two render samples shown in the above picture are made from exactly the same render from the same bag. The sample on the right was simply scraped much earlier during the drying process than the render sample on the left and the difference that can make on the outcome of the final colour of all cementitious renders can be quite profound. It is for this reason we strongly recommend that you complete customer samples so you can test and verify the colour with them before ordering any materials 

It is very common for applicators to scrape renders early, therefore the colours achieved on site could possibly be much stronger than the colours of manufacturer provided samples which are made in a laboratory under ideal circumstances. It should be noted that all manufacturers of cementitious render products would deem this to be normal behaviour of the product.

We are happy to provide assistance with this, please feel free to contact us!

Modern waterproof render systems are designed to cope with the changing weather conditions we regularly experience in the UK, but correct application is still essential. Even high-performance silicone render systems and monocouche renders can suffer from issues if they are applied during heavy rain, freezing temperatures or excessive heat.

Most waterproof render systems need stable drying conditions to cure correctly. If fresh render is exposed to rain too early, it can lead to streaking, patchiness or weakened surface strength. On hot days, rapid drying can increase the risk of cracking and inconsistent texture.

When carrying out silicone rendering for external walls, it’s important to follow manufacturer guidance carefully and protect freshly rendered elevations where needed.

Know your conditions

It goes without saying that before you begin the application process of any render, you should read and fully understand the application instructions supplied by the manufacturer.

The type of render system being applied is another factor to consider. Dry dash systems are more resilient to wet and cold weather than their silicone counterparts.

It is also advisable to check the weather forecast for your planned application dates – try to avoid any days with excessive rain, wind, heat or cold. Extreme weather conditions can severely affect the both the application and drying / curing times of the render. 

Simple Solutions

In hot weather, do not apply render on walls which are exposed to direct sunlight. Instead, start on an adjacent wall in the shade and follow the sun around the building. This method allows you to work in sunny weather, whilst avoiding any curing issues direct sunshine may cause.

Certain weather conditions will slow the curing process down – usually due to colder temperatures (less than 5oC) or high humidity (90% and higher). If this is the case, then the render will retain moisture for a longer period of time and if sustained will become more susceptible to damage from trapped moisture so it is essential that the render system is protected during this stage.

Ask an expert 

At Rendit, we offer a 2-year crack free guarantee on our Render Systems, so if you need any help applying your render contact Rendit today!

It’s one of those debates that always gets people talking on site.

Do we really need to two pass with K Rend and Parex, or are we just making more work for ourselves?

The honest answer is that there’s no single rule for every wall, every day or every product. A lot depends on the background, suction, weather conditions and how the material is behaving once it’s on the wall.

With systems such as K Rend one coat render and Parex one coat render, the term “one coat” can sometimes be misleading. Yes, these products are designed to achieve a through-coloured finish without traditional sand and cement backing coats, but that doesn’t always mean a single-pass application is the best option in every situation.

Some renderers are happy to apply monocouche render in one pass all day long, especially on consistent blockwork with manageable suction. Others prefer a two-pass application to help control thickness, improve consistency and reduce the risk of cracking or hollowness later on.

Personally, I think it comes down to reading the wall properly.

If the background is pulling hard or conditions are drying the render too quickly, splitting the application into two passes can sometimes give you a much cleaner and more reliable finish. On the other hand, if conditions are right and the material is sitting nicely, there are jobs where a single-pass application works perfectly well.

A lot of this also depends on experience. Some applicators know exactly how far they can push a wall, while others would rather play it safe and build the material up gradually.

The weather also plays a massive part. Warm temperatures, wind exposure and direct sunlight can all affect how quickly monocouche render starts to firm up. Trying to rush larger areas in difficult conditions usually causes more problems than it solves.

Whether you’re using hand application or spray on render methods, timing is everything. Getting enough material on the wall while still being able to rule and scrape it correctly matters far more than trying to save a bit of time.

There’s also the question of finish quality. Two-pass application can sometimes help create a more even appearance across larger elevations, especially when working with lighter colours or areas with inconsistent suction.

At the end of the day, most experienced renderers already know there’s no magic answer. Some jobs suit single-pass work. Some don’t. The important thing is understanding the wall in front of you rather than blindly following what somebody else says online.

K Rend and Parex are both solid systems when they’re applied correctly. Whether that ends up being one pass or two often comes down to site conditions, experience and personal preference more than anything else.

 If you would like more specific advice on the K Rend or Parex products we supply please contact us.

What is a "Halo Ring?" It's a renderers nightmare that's what it is! 

Halo rings in render are formed during the scraping process when an applicator unwittingly scrapes through the finish coat to the much harder base coat or first pass resulting in a flat textured area that cannot be matched into the rest of the wall. The worst cases may even go as far to reveal the mesh embedded into the first pass as the below picture shows:

Can they be avoided?

Most renderers I speak to have a story about a halo ring in either K Rend, Parex or other manufacturers mineral renders that caused them real headaches. Whilst we have had some success in correcting them with our Mendrend Render Repair System we cannot guarantee success under all circumstances as they all tend to be different. This is one of the most common issues we are asked to look at and if I'm honest the one we struggle with the most so if we can provide guidance to avoid it in the first place it suits us!

1. Before starting application check the walls with a long straight edge. If any bows or bellies over 3-4mm are present in the substrate then seriously consider the use of a K Rend or Parex base coat instead of just priming to level the walls out ready for the finish coat.
2. If applying a base coat ensure this too is level with a straight edge before applying the finish coat. Ensure that the K Rend or Parex finish coat is applied to a depth of at least 12mm over the top of the base coat to allow 2mm to be scraped with little risk of scraping too much away.
3. If you aren't applying over a base coat and instead applying the finish coat in two passes, do not apply the first pass too thick, we advise the first pass should be around 6mm maximum and level for both K Rend and Parex. The second pass should be at least a further 12mm on top of that applied wet on wet.
4. It is common for suppliers to under estimate the amount of material you will need in an effort to look like they are the cheapest or doing you a favour. They know that you will be straight back on the phone if you are running out of material and trying to get a job done. What generally happens instead is that the inexperienced applicator starts to take risks by spreading thinner. Always ask your supplier to justify the quantities quoted, backed by a manufacturers specification document. It's always better and cheaper to have a few bags left over at the end of the job rather than running out of material. Always ensure you allow 5-10% additional material for wastage on top of manufacturers quoted consumption figures as that doesn't tend to be included. You'll figure out how much you will need to allow for this yourself once you get a feel for the material after using it for a while. 
5. Every applicator uses a slightly different amount of material to the next due to differing working patterns. Keep a record of material consumption over a few jobs to see if you get consumption rates that suit you.

Avoiding this issue is as simple as that! Hopefully you find this of help and avoid the renderers curse in future!

Choosing the right render for a property is about more than just appearance. Factors such as the building substrate, exposure to weather, maintenance requirements and overall performance should all be considered before selecting a render system.

Modern render systems are available in a wide range of colours, textures and finishes, with each offering different benefits depending on the project requirements. From traditional sand and cement render through to modern breathable render systems, choosing the correct product can have a significant impact on both the appearance and long-term durability of a building.

One of the most important considerations when selecting a render is breathability. Breathable render systems are designed to allow moisture vapour to escape from the wall structure while still protecting the surface from rain and weather exposure. This can help reduce trapped moisture and minimise issues such as cracking, staining or damp-related damage over time.

For older properties or buildings with solid wall construction, breathable render systems are often preferred due to their ability to manage moisture more effectively. Modern silicone render systems are also popular thanks to their flexibility, water repellency and low-maintenance finish.

Monocouche render remains a widely used option for both residential and commercial projects. As a self-coloured render, it provides a durable decorative finish without the need for regular painting, making it a practical long-term solution for external wall rendering.

The texture and finish of the render should also be considered carefully. Smooth, scraped and textured finishes can all dramatically change the appearance of a property, while different application methods can influence the final look and performance of the system.

Building location can also play a role in choosing the right render. Properties exposed to coastal conditions, heavy rainfall or pollution may benefit from render systems with enhanced water repellency and dirt resistance.

Ultimately, choosing the right render comes down to balancing aesthetics, performance, maintenance and suitability for the substrate. Seeking professional advice can help ensure the selected system is appropriate for both the property and the environment it is being applied to.

Whether you are renovating an existing property or working on a new build development, modern breathable render systems provide a reliable and attractive solution for long-term exterior wall protection.

I regularly hear people proclaim that their monocouche or through coloured scraped renders are "non-maintenance," and they are often a little flabbergasted when they are told that their render needs cleaning. This is a common misconception and usually comes down to a misunderstanding of what "non-maintenance" actually means.

Modern renders are incredibly hard wearing; a correctly applied system will withstand many years of whatever the elements throw at them, even in extreme circumstances. I drive past a rendered property that was rendered nearly 30 years ago which, despite being subject to heavy flooding (over 8ft deep at numerous points), still looks great today with no sign of the render failing anytime soon.

On that basis, modern renders are certainly expected to be low-maintenance. Once installed correctly, you'll have a hell of a time removing them, and re-applying within the next couple of decades should not be necessary.

This doesn't mean that some systems, not all, will need some kind of regular cleaning. This is the case for all properties in the UK, regardless of whether the walls are brick, stone or render. Thankfully, it's not overly difficult to either take preventative measures or clean the surface once it starts to look a little dirty.

If you have signs of algae growth, we'd recommend you be proactive and treating it with a good algae cleaner before it spreads. We have some available on our site here or here. These tend to incredibly easy to apply as they simply are sprayed through a normal garden low pressure spray. Algae is stubborn and can grow on almost anything given the right conditions, so it's better to nip it in the bud before it spreads. 

Light pressure washing can also be carried out, as long as care is taken not to apply too much pressure which may damage the surface. Industrial washers may be too powerful, but your average consumer grade washer that you buy from B&Q should be fine. Good quality non-acidic patio cleaners applied before washing down will also help with dirt removal. 

So what about exterior render paint?

We’re often asked whether applying exterior render paint is necessary to keep a property looking fresh.

With modern monocouche or through-coloured systems, the colour is built into the material itself. Unlike traditional sand and cement render, these systems do not rely on exterior masonry paint to achieve their finish. As a result, repainting should not form part of the normal maintenance cycle.

Exterior render paint is generally more relevant on older rendered properties where the original finish has faded or where a colour change is required. It’s a cosmetic solution rather than a structural one.

If you are looking to prevent dirt and algae build-up further, specialist breathable sealers can be applied. We will shortly be launching a new product we have developed called ProtxSeal which is incredibly easy to apply, again using a low pressure sprayer. Containing Siloxanes, ProtxSeal completely repels water and seals the render with a lotus leaf effect whilst still allowing the walls to breathe. Dirt and algae simply get washed away as it can no longer stick to the surface. This sealer is easy to apply through a normal garden spray, does not change the appearance of the render at all and can be used on ANY porous masonary surface.

We will also shortly be offering application services also for this product, please contact us for more details.

If you need any advice on how to keep your render looking fantastic for years to come do not hesitate to give us a call.