Not all insulation was created equal!
How well insulation performs is governed by its thickness, its thermal conductivity and how well it is installed. This makes different materials suitable to different applications. Here we describe the unique characteristics of aerogel and the best places to use it.
What is aerogel?
Aerogel consists of near-vacuum gas trapped inside a matrix of material. The product was originally developed in the 1930s and has a range of applications, primarily as a lightweight insulating material. More information can be found on Wikipedia.
The product is solid (not a gel) and has a very low thermal conductivity. It is made from silica which undergoes a super-critical drying process to create the lightweight gas it contains. This product is a desiccant and can have a drying effect on the skin, so the use of protective gloves is highly recommended when handling the product.
The product is usually produced in matts 5 or 10mm thick. The thermal conductivity of 0.015W/mK is 30% better than the leading foam board products. Its flexible nature also means it can be installed more reliably, and in more situations, than rigid insulation products.
Aerogel is also vapour permeable (vapour-open), which means that moisture can permeate through it. This makes it ideal for retrofit of existing buildings and highly suitable for use in traditional buildings, where moisture and ventilation is a significant concern.
Where can I use Aerogel insulation?
Aerogel matts have a range of applications in different industries, from aerospace to construction.
In construction they can be used as wall, floor or roof insulation and are ideal for retrofit projects.
Wall Insulation
As with any insulation product its use on walls depends on the construction build-up. Aerogel can be used on solid walls (brick or stone), but the application will vary depending on whether the bricks or stone are highly porous, whether there is external render and depending on the internal finish. The vapour open nature of aerogel means that it can allow moisture to permeate the wall, but expert advice should be sought before installing the product. Please get in touch with our technical team to confirm your application.
It can reliably be used to insulate timber frame walls, but please check with our technical team to make sure you get the most out of your installation.
Wall finishes must be tailored to suit the specific application. Foil-faced plasterboard is not recommended where vapour permeability is required and many paints and wallpapers can also trap moisture.
Window Reveals
One of the most common uses for aerogel in buildings is around window reveals. Windows installations frequently result in thermal bridging between the window frame and the wall insulation. This is particularly true in traditional buildings where windows are located toward the outside of very thick walls. This can be overcome by insulating the window reveals such that there is an insulation bridge from the wall insulation to the window frame. Aerogel is ideally suited to this situation thanks to its high performance and vapour permeability.
Roof insulation
Cold Roofs - Aerogel can reliably be use to insulate at ceiling level in a loft space, or on room-in-roof stud walls. It’s not usually cost effective to use aerogel in this situation, but if you think you would benefit from the additional performance of aerogel in this application please get in touch and our technical team will be pleased to advise.
Warm Roofs - Aerogel is very well suited to insulating loft conversions and room-in-roof spaces, including dormers. It can be applied internally over the existing plaster finish where space constraints are tight. This can give good performance and eliminate the thermal bridging from roof timbers.
Aerogel can also be applied to the rafters in a roof, however careful attention should be paid to the junctions at the eaves, the ridge and the gables, to ensure that the insulation is continuous and airtight. Please consult our technical team for advice and guidance.
Floor Insulation
Solid Floors - Aerogel blankets are ideally suited for solid floors. The high performance means that a thin layer can still be effective which reduces the need to trim internal doors or skirtings.
Floor finishes will dictate the thickness of insulation that can be applied and timber battens may be required to spread the load of the floor. A membrane over the aerogel may also be required to maintain airtightness.
Suspended floors - the most cost effective way to insulate a suspended timber floor is usually from beneath. However, this isn’t always practical with shallow sub-floor voids.
Need further guidance?
Our technical team are ready to assist with your application and we always recommend getting independent advice from a Retrofit Advisor or Retrofit Coordinator when considering changes to your home.