Twenty five percent of all heat loss is through an uninsulated roof. Insulating your loft, attic or flat roof is a simple and very effective way to reduce your heating bills and good quality insulation will last for up to 40 years.
In this article we will explain the best way to use insulation so you get the maximum benefit. For people planning an extension or new build we’ll also explain the most effective products for insulating walls because about a third of all heat loss is through walls in poorly insulated homes.
If your loft is dry and access is easy it should be straightforward to insulate it and in most cases you can do the work yourself. A layer of insulation should be laid between the floor joists. To maximise the insulation another layer should be laid at right angles to cover the floor joists and bring the insulation to the optimum depth. We can provide loft rolls that have partially cut perforation at either 400 or 600mm centres to fit between the floor joists or the rolls can be used unsplit at the full width for the second layer.
Laying boards over the insulation
If you are planning to lay boards over the insulation and have only insulated between the floor joists, the insulation won’t be thick enough. Ideally the floor should be raised either by fitting timber battens across the floor joists or by fitting plastic legs that fit on the floor joists and support the floor. This will allow for the second layer of insulation. A gap should be left between the insulation and the floor boards to allow for ventilation. It’s important that the insulation isn’t squashed when fitting a floor as this will impact on its effectiveness.
Another way to insulate your loft is to fit insulation between your roof rafters. The easiest way is to fit rigid insulation boards carefully cut to fit between the roof rafters. This will make the roof space warmer so will help stop pipes and water tanks from freezing. Another advantage is it won’t be necessary to double the thickness of the floor insulation if you want to board your loft floor.
A point worth noting is that if you are just insulating the floor of your loft the insulation will stop heat from escaping from your living spaces, so it will make your loft cooler. This may introduce or worsen damp problems or condensation so if you are carrying out the insulating yourself you may need to increase ventilation in your loft space.
As explained previously a third of a homes heat can escape through uninsulated walls, so if you properly insulate your cavity walls that will dramatically cut costs from your heating bill. We can provide Knauf DriTherm non-combustible cavity slabs designed for external wall cavities to provide a full fit solution or Knauf XPS Laminate Plus CFC and HCFC extruded polystyrene wallboards that offer enhanced thermal performance - ideal for refurbishment and new build applications.