What is insulated render?

We get plenty of people calling us to buy insulated render, but often they don’t understand exactly what that means. Insulated render does not mean insulation within the render itself, it is simply another way of saying a layer of insulation buried beneath the render. In the industry, the more commonly used term for this is external wall insulation, or EWI. There are many variations on this product available, but they all have one key thing in common: there is a layer of insulation fixed to the wall, and then a layer of render applied on top.

How is insulated render installed?

For most systems, a mineral wool or expanded polystyrene board is fixed to the wall with adhesive and mechanical fixings. This insulation sits on the outside of the wall and is usually 90-100mm thick, although there are other thicknesses available. The surface is prepared and a basecoat is then applied. A fibreglass mesh is run through the base coat to add strength and create a strong stable surface on which to apply the top coat. Lastly, a top coat of acrylic, mineral or silicone render is typically applied to create a quality finish.

As part of the job, plumbing is often adjusted to accommodate the insulation, and windowsills will often need to be adapted to allow the insulation to fit underneath. The whole process will take a couple of weeks on the average house, and you will end up with a very different looking property to when you started.

Typical components of insulated render

Although there are different systems available, a good insulation job will have the following as part of the system:

  • Insulation board made of EPS or mineral wool
  • Adhesive to fix the boards
  • Mechanical fixings to attach the boards
  • Base coat to apply on top of the boards
  • Mesh to lay into the base coat
  • Starter track and beading where appropriate to create clean, straight edges
  • Top coat to create a quality finish

If any of these products are missing from your insulation job, you should probably check that your installer is doing all the stages necessary.

What does EWI Store offer?

EWI Store is one of very few retailers to specialise in external wall insulation. Where there are plenty of rendering suppliers out there, we really pride ourselves on our external insulation systems and have plenty of options to offer you in store and on our website. If you have any questions about how EWI works and if it might be right for you, or you have a technical question on how to install the systems, just give us a call and we will be happy to help.

Whilst you are here, you may want to check out our calculator. This tool allows you to get an immediate quote for your EWI materials, by simply inputing the size of your job.