What Causes External Render To Deteriorate Prematurely?

The rendering of external walls offers a multitude of benefits including the obvious aesthetic improvement, enhanced durability of wall materials due to the shielding of external elements, can prevent cracks due to enhanced flexibility, better insulation, to name a few. When you invest in rendering the external walls of your property, you expect it to last. But there are a few factors that can prematurely deteriorate your rendered walls, leading to costly repairs or unsightly damage. 

So, what causes this premature deterioration of rendered surfaces? Several different factors can impact your external render, including exposure to dampness caused by blocked downpipes and inadequate roof drainage, extreme weather, both of which extended exposure to moisture is at the root of. Additionally, some rending companies choose to make money go further by stretching their materials and not telling homeowners, leading to compromised properties and inadequate thickness. 

We’ll explore the potential causes of early deterioration so you can work on preventative measures, keeping your investment looking great for much longer. 

inadequate waterpoofing wall leak

Extreme Weather Conditions

Render is applied to an external wall in the effort to protect your building’s exterior from the harshest weather conditions. However, that same weather can result in significant wear and tear over time. Extreme heat and heavy rain are two types of weather that can have a lasting impact on your exterior render. Eventually, cracks and small chunks of render can be separated from the wall, beginning the deterioration process as this leaves the internal wall and the rest of the rendered surface exposed to the elements. 

Leaking Downpipes or Poor Roof Drainage

After your render is installed, you need to maintain it. Part of this maintenance is ensuring your downpipes are properly working. If they’re blocked or leaking, it can lead to excess moisture exposure that causes premature deterioration of your walls. At first, you may not notice the damage this is causing. However, when you finally have the downpipes replaced, you’ll find the render also needs to be replaced. The same is true if your roof has inadequate drainage. It can expose the render to more moisture than usual, causing rapid deterioration. So, if you notice a problem with your drainage or downpipes, it’s important to call your local roof plumber as soon as possible to prevent prolonged exposure to moisture. 

Inadequate Application of the Render 

Remember that old saying, “You get what you pay for” It’s true with render, too. If you don’t hire a high-quality rendering company for the job, you will likely end up with an unsightly mess due to early deterioration. Some companies will try to stretch materials out by adding excessive water, leaving you with a less protective coating. Others will get the mix wrong, causing the paint to be unable to adhere to the render. Regardless of the exact situation, the outcome is the same—unattractive and deteriorating render. The way to prevent this is to hire a reputable rendering company with a proven track record for durable results. 

Builders in a Rush

The proper way to apply render is to allow it to cure properly after application. This allows all the water content to evaporate. The problem is many builders will not wait this long. If the paint is applied too soon, it will not have an adequate bond with the render and will eventually peel and flake off, leaving you in a mess. 

Inadequate Waterproofing

broken gutter prone to leaking

Having your rending properly waterproofed is essential. However, the process takes a long time and can seem tedious. Generally, it will require two coats, and even the tiniest missed spot can allow water to seep in. This will result in the need for costly repairs. While render and paints are designed to keep water out from the exterior, they can’t repel that which comes from the interior. So, any leaks from your roof or balcony can work their way behind the rending and then work their way out, causing damage along the way. 

Structural Movement

If your building moves due to soil conditions or a poor foundation, it can also cause deterioration of your render due to the flex required exceeding what the surface can take. This structural movement encompasses many things, including sway and expansion. When there is structural movement, it will manifest as cracks in the render, this unfortunately is a sign that costly repairs could be required as structural changes aren’t an easy fix, especially if your house is on a slab and most rendered houses are. There cracks also leave the rest of the rendered wall exposed to the elements. 

Painting or Texture Coating Applied Before the Primer or Sealer

When the render is applied, it’s essential to use primer or sealant before any paint or texture coating is applied. This process will neutralise certain elements, such as salt, that can leech through the render and push through the paint. If this process isn’t followed, it can lead to early deterioration of your render. It’s unfortunately become a common practice with many rending professionals to skip this step in favour of cutting costs. While they make out better for it, you’ll be the one footing the bill in the long run. 

Lack of Routine Maintenance

Many homeowners think that once exterior render is applied, it’s a done deal. However, this isn’t the case. Most manufacturers recommend annual cleanings and top coat applications every 7–10 years. Unfortunately, many homeowners are either unaware or don’t think this really applies. The results can be catastrophic, with severe deterioration. Without the recommended maintenance, you could be looking at a complete replacement.

Act Quickly To Save Your Render

When you first notice signs of deterioration in your exterior render, you must act quickly. Letting the problem go too long can lead to costly repairs and even needing to remove and replace the render in sections or all together. To keep your home or business looking great, understand these causes of premature deterioration and do what you can to prevent them from happening. 

Unfortunately, not all rending companies are the same; some will cut corners during installation. If you’re unfamiliar with the process, you may never know this happened until it’s too late. 

Remember, once your render is installed, your job isn’t over. You must take care of it like other parts of your building. Annual cleanings and top coatings every 7 to 10 years are essential for maintaining its beauty and durability. Work with a reputable rendering company with a proven track record for long standing results.