Due to the national shortage of PIR (Celotex, Kingspan etc.) insulation, we did some research into alternative solutions at Thames Design & Build.
We came across Actis Insulation, which have a product called Hybris, which can be installed between studs, rafters and joists as an alternative to PIR board in lots of situations. When this is combined with their HControl Hybrid or Boost Hybrid products, the required U-Values for Building Regulations are easily achieved.
The pros and cons of this product are as follows: Pros: Cheaper than PIR Cleaner to use than PIR Easier/quicker to install than PIR Acts as a vapour control layer when HControl is taped Cons: Not suitable for all applications, such as cavity walls and warm deck flat roofs
www.insulation-actis.com