Top up loft insulation on top of boarding?

[Div]

Hi,

My loft is partly boarded (nailed down chipboard) and was insulated with a thin layer of glass fibre insulation (beneath boards) many years ago. Is it Ok to top up the insulation by rolling out a new layer straight over the old and the boarding (where present). This will be far easier than removing the boards and I will not store or walk in the loft after this. Any comments/ thoughts appreciated!

 

[kevnurse]

You can do what you want. For the purposes of measuring the insulating effect of your proposed arrangement, you should not include the wood in the total thickness of the materials. Air is a better insulator than wood, which is why wool is used.