A quarter of heat loss in an uninsulated house happens through the roof, which is why it is vital to make sure the loft is properly insulated if the house is to stay warm without costing the owner a fortune in energy bills.
There are many different products to choose from when insulating a loft, each with its own benefits and drawbacks. One of the most important characteristics of an insulation product is its U-Value, which measures the effectiveness of a material in preventing heat transfer. If you bear in mind the Energy Saving Trust’s recommended U-Value for an insulated loft is 0.16 W/m2K, that will help you gauge the efficiency of these products.
The most essential loft insulation products
Quinn Therm PIR insulation boards offer an easy and cost-effective solution when insulating above the rafters. Made of polyisocyanurate foam, these are essentially sheets of gas-filled cells with a layer of foil on either side. They come in a variety of thicknesses, from 20-150mm, are lightweight and can be easily cut down to size with a handsaw, making them a versatile solution. They have a U-Value of 0.022W/mK.
However, the foam material does cause a lot of mess when cut, so be careful to use a dust mask and goggles if working with this product.
A cleaner and more modern alternative is the Actis Hybris Panel. This comes in sheets of honeycombed polyethelene foam with aluminium-coated polyethelene foil exterior, and is available in thicknesses of 50-205mm. With a U-Value of 0.033W/mK it’s more efficient at maintaining heat than Quinn Therm, but comes with a higher price tag.
YBS SuperQuilt is a multifoil – a type of insulation made of multiple layers of foil. It’s lightweight and only 40mm thick, but offers effective heat retention and vapour control, with a U-Value of 0.022W/mK. It is installed under the rafters in combination with PIR insulation boards and is easy to cut and handle, with no protective clothing required.
Actis Triso Super 10+ is a triple layer multifoil that’s only 35mm thick, yet offers airtightness, insulation and vapour resistance. It has a U-Value of 0.04 W/Mk, which is equivalent to 210mm of mineral wool. A popular way to use this is to combine it with a high efficiency foam, and because of its thinness it makes it easier to insulate a roof with restricted head height. It is installed under the rafters using staples and tape to ensure an airtight finish.
Knauf Earthwool Loft Rolls consist of traditional glass mineral wool insulation, and are best laid at ceiling level to insulate cold lofts. It comes in two versions, 40 and 44, which offer U-Values of 0.040 W/Mk and 0.044 W/Mk respectively, and provides superior fire resistance. It’s a material that will be familiar to many, and represents very good value.
If you’re considering converting your loft into a room, Rockwool Sound Slab provides excellent soundproofing. Made from stone, this dense insulation material is also non-combustible, and when combined with Gtec DB Plasterboard greatly reduces both internal and external sound.
Our Kingsfold depot is currently home to a Rockwool demonstration tunnel that customers can walk through to experience the effectiveness of its soundproofing. Why not drop by to give it a try?
In the meantime, you can also read our blog on how to insulate your home effectively
We always carry sufficient stock of insulation products, and our friendly staff are experts in their use, so If you have any further questions about the best materials for insulation, don’t hesitate to get in touch.