Insulation can save homeowners a great deal of money on their heating bills and significantly reduce their CO2 emissions – however when the insulation is squashed, can it impact the cost of heating, and will it possess the same benefits as insulation which isn’t squashed?
A research into the thermal resistance of loft insulation when compressed was carried out by National Physical Laboratory (NPL) -and an NPL Technology Innovation Fund project was set up for this work.
The recommended thickness of insulation is 270mm, therefore the research tested the thermal resistance of loft insulation at this recommended thickness, and then also looked into the thermal resistance of insulation at a thickness of 100mm – these were then compared. Whilst the thermal resistance of insulation at the recommended thickness was a good 6.11 m2.K/W, insulation at a compressed 100mm was half that at 3.09 m2.K/W.
NPL’s Ray Williams, who worked on the project, said: “There are rigorous requirements for manufacturers of insulation to quote performance values based on accredited measurements, but further measurements have shown that achieving this in practise requires correct installation.”
The Carbon Trust recently sponsored a survery which has shown that 82% of households utilise their lofts for things such as storage, and so were squashing the insulation by either placing boards over the top, or were simply placing items directly on to the insulation itself.
Amazingly only 26% of homeowners knew that my compressing insulation, it is significantly less effective – which shows there is a communication issue between the manufacturers and homeowners. This essentially means that a great deal of homeowners are reducing the effectiveness of their insulation without even realising it.
What homeowners really need to do, if they are considering using their loft for storage or other usses, it to protect their insulation first.