12/29/2023 0 Comments Installing rafter vents diagramAgain, the approach would differ if the loft is being used just for storage or if a full-blown conversion is being done. Many lofts will have an external wall dividing the property from the outside or that of the neighbours and sometimes that wall should also be insulated. Insulating External Walls Within the Loft When we’re installing VELUX roof windows we use their BDX insulation frame which is a foam frame that surrounds the window and keeps everything properly insulated. If you’re getting roof windows installed it’s really important that they are insulated around the window frame to prevent thermal bridges (that can be a major source of energy loss in homes). To maintain this air gap from one side of the roof to the other, the roof ridge can be squared off with noggins to carry the insulation, creating a cavity above.Īdditional air vents (with lap vents or vented roof tiles) can also be installed to ensure some air does circulate within the main loft space.įinished loft with VELUX window, lighting hatch and ladder Roof Windows & Thermal Bridging When applying rafter insulation, and as we mentioned above, a minimum 50mm air gap should be kept in place between the insulation and the roofing material. It’s very important to maintain sufficient airflow within the loft to prevent condensation. Get a quote from us Some Important Considerations Airflow in the Loft Therefore we’d recommend getting a quote based on your exact requirements. The installation cost for either the foil membrane or rigid board insulation would vary quite a bit. At The Loft Boys, we use high-quality foils manufactured by YBS. The foil membrane however can be bought relatively cheaply online for as little as £15 per roll. So as you can probably already see, it does get expensive quite quickly! VAT from Insulation4Less and that amount would cover an area of 11.52m2. We found a price for 70mm (pack of 4 boards) of £225.00 inc. Pricing for that would be based on the thickness required. The rigid board insulation we would normally use is called Thermapitch TP10 which is made by Kingspan. What Can Be Put On Top of the Rafter Insulation?Īll three of the insulation types above can be covered with plasterboard or plywood although for the foil membranes counter battens are needed to help keep it in place and provide a way for the boards to be attached. It’s ideal for lofts that are used solely for storage purposes as a useful way of maintaining the temperature of your stored items. Single-Layer Foil Insulation is an aluminium-based membrane that, when applied to the roof rafters, can help to regulate the temperature within the loft space. We normally recommend this type of insulation for “hobby rooms” which are used more often than those just built for storage. Multi-Layer Foil Insulation is an aluminium-based membrane that when applied to the roof rafters, can help to regulate the loft space by stopping temperature influence from outside of the property. Compared to the foil insulation outlined below, this is the most expensive option, both in terms of the cost of material and the labour involved in installing it.Ī roll of foil insulation Multi-Layer Foil Insulation (You can read more about u-values and the science of insulation on our guide page.) PIR comes in a range of different sizes from 12mm to 150mm. A 62.5mm insulated plasterboard would then be installed across the room side of the rafters to achieve the required u-value of 0.20 W/m2K or lower. Rafters would normally need to be extended to 120mm to accommodate a 70mm PIR inserted and a 50mm air gap. It’s made of PIR (polyisocyanurate) and normally inserted between the rafters with a minimum of a 50mm gap between it and the roofing material. This type of insulation is generally used when a full loft conversion is being done. There are commonly three main types of rafter insulation used in the UK: PIR Rigid Board Insulation Single-Layer Foil Insulation and Multi-Layer Foil Insulation. What Types of Rafter Insulation Are There? We go into more detail on cold vs warm lofts in our insulation guide. We refer to this type of loft as a “warm loft”. This insulation will retain heat within the loft in the colder months and reflect heat in the hotter months. Plus, it will help to increase thermal efficiency. Exposed insulation was applied on top of the rafters Why is Rafter Insulation Necessary?Īdding rafter insulation to the underside of your roof will help regulate the temperature in the loft.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |