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LOFT INSULATION
LOFT IN SPACE ccording to government data, there are around 8 million uninsulated, poorly or under insulated lofts in the UK. Which means there will be plenty of opportunities for builders over the coming months and years to help households improve their home energy efficiency by installing or upgrading their loft insulation. As with any refurbishment project, a cold roof insulated at ceiling level will need to meet the limiting U-value (minimum thermal performance standards) set out in Approved Document L. This was updated in June 2022, so a cold roof
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66 FEBRUARY 2023 PROFESSIONAL BUILDER
Bradley Hirst, Technical Services Manager at Knauf Insulation, explains why loft insulation should be installed to a depth of 500mm. insulated at ceiling level will need to achieve a U-value of 0.16 Wm2K. Installing Knauf Insulation’s Loft Roll 44 to a depth of 270mm will meet the minimum standards, but we know that, where energy efficiency is concerned, the thicker the insulation, the more effective it will be at preventing heat transfer. For this reason, many new homes are now being built with loft insulation to a depth of 400500mm. So, if you’re doing a loft installation, advise your customers to do
the same to help cut their bills as much as possible.
Top up or replace? If the loft already has some mineral wool insulation installed, builders will need to consider whether it can be topped up or if it needs to be replaced. Mineral wool insulation will last for 50 years or more, so providing it’s been installed correctly and isn’t damaged, it will be fine to insulate over the top.