If you’re looking to install external wall insulation, it can be difficult to know which system is best, who is qualified to install it and which insulation materials you should use. It’s important to remember that when you choose a quality system, a quality installer is essential to make sure that it all stays in great shape.
The key elements of an external wall insulation system are the insulation boards, the adhesive and the render finish. Let’s take a closer look at the different material choices.
Mineral Wool, EPS, or Wood Fibre?
At EWI Store, we stock lots of different types of insulation board including EPS, Mineral Wool, Wood Fibre and Kingspan K5. These all come in at different price points due to their different insulating capabilities.
Expanded polystyrene insulation is probably the most common material used for external wall insulation. This is because EPS is very cost-effective, easy to install due to how lightweight it is, and it has excellent thermal capabilities. To reach building regulations on a solid wall property, a 90mm board of EPS will bring the building in line with the required U-values.
Mineral Wool is the same material used in lofts and cavity walls, except for external wall insulation it is compressed into a rigid board. Mineral Wool has excellent fire resistance, is completely breathable and also offers acoustic insulating properties. It’s a high-performance material that is incredibly hard-wearing and can be used for most external wall insulation applications.
Wood Fibre is fairly new to our range and is our most breathable and eco-friendly EWI material. Pavatex Wood Fibre is a completely renewable material with very low pollution levels. It is great for installation onto timber frame properties due to its high levels of breathability.
Browse our full range of insulation materials here.
What Type of Render?
External wall insulation boards need to be finished with a protective thin coat render. Thin coat renders are very lightweight, flexible, crack-resistant, and they can be tinted to create any colour. We sell a few types of thin coat renders, each offering varying levels of performance.
- Silicone Render/Silicone Silicate Render: Silicone Render is a premium, modern technology coloured render – which is available in hundreds of different colours. Silicone is a very popular choice because it offers hydrophobic properties, which means that it repels water, dirt and organic growth – so it probably requires about the same maintenance as pebbledash (very little). Silicone Render is also super easy to apply because it comes ready to use, so you just apply it straight out the box. (Read more about Silicone Render here).
- Acrylic Render: Acrylic Render is very similar to silicone, except for it doesn’t provide the same hydrophobic properties. It’s a solid middle-ground thin coat render because it still provides the same flexibility, but it’s also great at holding onto colour pigment. This is a fantastic choice if you are looking to replace pebbledash with a coloured render. (Read more about Acrylic Render here).
- Mineral Render: Mineral Render is a dry-mix, thin coat render. This is a very popular choice if you live in a cold or rainy climate (as many pebbledash homeowners do – Scotland, coastal homes!) because Mineral Render is extremely fast drying (you can’t apply other renders in cold/rainy temperatures because they take longer to dry). The only thing about this render is that you need to paint it afterwards with silicone paint to seal it in. This is because if it’s left exposed to the elements it can develop lime bloom due to the presence of Portland cement. (read more about Mineral Render here).
Finding a Trusted Installer
We work with a range of trusted installers up and down the UK who have undergone the EWI Pro training course. We can recommend you a few experienced installers who are experienced and familiar with our systems, so fill out the form below to get in touch!