How long does render last?
Render is one of those things you want to fit and forget – once it is on the wall, you want it to last a lifetime. So make sure you get it the right first time!
Which type of render lasts the longest?
There are several different finishes and bases that you can use on your wall, and each will have its lifespan. Any BBA-certified render that goes on your wall will have to have a 25-year lifespan as a minimum (subject to suitable maintenance). Some will far exceed this, while others will only meet the target longevity rather than exceeding it.
Sand cement renders, which are the oldest (and for many years most common) type of render, can have a very short lifespan. They tend to crack more easily than modern renders, and they therefore open themselves up to water ingress and biological damage, as well as looking very unsightly. In less than ten years, even if installed correctly, you will likely see cracking and damaged render.
Modern combination renders with an adhesive base coat and mineral, silicone, or acrylic top coats are much more flexible and less liable to cracking so that they will have lifespans of 25 years plus EWI Pro has had their systems certified by the BBA to last at least 30 years.Biological influence on renders
Even though a warranty may suggest a lifespan of 25 or 30 years, vegetation growing on walls can significantly reduce that. Vines, Ivy fungi, and moss can all cause damage to the render and staining to the top coat. As part of our warranty, we always ask that the walls be kept free of all vegetation. This will help ensure a full lifespan for your render.
Furthermore, some renders will contain an inhibitor that works as a fungicide and herbicide to prevent unwanted biological matter building up on the walls.
Maintenance
While some renders will have inherent lifespans that are longer than others, the important thing to note is that unless the system is maintained according to the manufacturers instructions, the lifespan may be diminished, and the warranties may no longer apply. EWI Pro has several important stipulations that cover their warranty – one being that the walls should be painted once every 8 to 10 years, for example. If these instructions are followed, the render should last long.
Pebbledash and durability
While it may look outdated and uncool, pebbledash is still great for areas where a hard-wearing render is required. Pebbledash that 100 years or older can still be seen on many UK properties, and the reason is that it that is so hard wearing and resistant to damage that it really can last that long. Having said that most of these older pebbledash renders are cracked and not working entirely as intended. They are usually sand cement, so non-breathable, and are prone to frequent cracking. So it is probably time to look at replacing these old renders.
Remember that when replacing old render, you will need to strip it off the wall first, unless you are insulating the property at the same time. Pebbledash is arduous to strip and dispose of, so insulation is a suitable option.
It is how you install, not just what you install.
While the materials you use are obviously important, you also need an installer who knows what they are doing. A substandard installer can take the right materials and produce a poor finish, which won’t last the test of time. If you combine quality and correctly specified materials with an experienced and good quality installer, you will end up with a render that will last generations.
Remember that if you need a quote for your render or insulation work, just get in touch with Be Constructive. We can quote you for a full range of different render and insulation systems to suit your home, expertly installed by our experienced teams.
4 comments
I am getting a huge range of ages from the different quotes I’ve had. Is silicone render the one that will last the longest, or does it not matter? I am a bit worried about EPS as I fear it might break up in the wall – is it really going to last 30 years?
Hi Max,
Silicone render is going to last the longest in terms of top coat, but all the insulation we install comes with a 25 year warranty as a system, so you can be assured that whatever materials or render you choose, you are going to get a long lasting system.
Best,
Alan
Hello,
I have a question regarding steel and façade insulation. Can you fix the insulation to steel? I am not sure of the coating on the steel and if it is suitable for insulation
Thanks
Hello Altado,
External Wall Insulation is usually ok to go over steel. You may want to ask your paint question to Surrey Steels – They are a good steel supplier in south west London with a very helpful sales team. You can reach them at http://surreysteels.com/
Best,
Alan