Just 10mm of aerogel insulation board could halve the heat lost through some old solid walls because it is so high performance. Here are some typical areas where aerogel boards can be the perfect answer to lack of space when you are retrofitting solid walls with thin insulation:

Window reveals and window heads are often the coldest part of a wall; it's easy for condensation and mould to form here if you don't insulate it. But unless you're replacing windows there's often little space, so aerogel is the ideal solution.

Underneath sills: often a cold spot with lots of air leakage, some airtight tape and aerogel board can help make a big difference.

Door jambs: much like window reveals, these can be a real cold spot. Once the aerogel board is installed, our primers and plasters make it simple to coat.

Bay window insulation: thick boards can ruin the aesthetics of a room, whereas aerogel can be an invisible upgrade.

Cornices: where valuable plasterwork is in place, often aerogel is thin enough not to disrupt the appearance.

How thick is it?

The board itself is 10mm thick, and you'll also need a finishing plaster, and adhesive underneath and possibly a levelling (or "parge") coat to eliminate air gaps.

How to install aerogel insulation boards on solid walls

You can download our guidance by clicking here.  With insulation, sometimes less is more, so our system focuses on the quality of the installation, not the thickness. That's why we use Silic8 Aerogel Adhesive and lime base coats are breathable and mineral - to keep the wall airtight but vapour open. Finishing with our Solo One Coat Lime Plaster gives a durable, compatible finish. We follow the UK Government's best practice guidance for insulating solid walls, which recognises this approach is the most effective low risk way of thermally upgrading cold old walls.  

How warm is a wall insulated with aerogel?

There are some typical U values below. Remember, these ignore air leakage and wet plastering with Solo makes a big difference.

9" Solid brick wall:  typical U value uninsulated U = 1.65

9" solid brick wall with 10mm Aerogel and 6mm Solo: U= 0.80

 

What should I use where I don't need very thin wall insulation?

Our standard Warmshell Internal system is ideal for solid walls requiring a thermal upgrade. It uses the same Solo lime plaster to finish, but Warmshell Woodfibre for insulation. These boards are warm, sustainable and perfect for managing moisture risk in solid walls.  Combined with Warmshell Aerogel in the hard to treat areas like window heads, you can install a highly effective retrofit wall insulation system on your walls.

Can I fix the boards with squirty foam?  

Foam adhesives are a high risk method of installing  IWI (Internal Wall Insulation), which is why they are not recommended by the government's best practice guidance for insulating solid walls. They leave air gaps on the cold side which allows air leakage and create an area for mould to grow. Our full bed of mineral Silic8 adhesive is safer from a fire risk and moisture risk point of view.

What is the fire classification?

The board is Class A2 for fire and our compatible lime plasters are Class A1.