For the next few days, Focus DIY stores are doing a special '3 for the price of 1' on their combi packs of 100mm loft insulation, each of which covers 13.89 sq m @ £19.99.
Normally this is on sale as 2 for the price of 1 @ £19.99.
They are also offering a 15% discount on all transactions with their loyalty card, so that the cost is now reduced to £16.99.
So you get 3 x 12180mm x 1140mm x 100mm thick for £16.99, which is about 40p/sq m. Not bad at all.
David J