"I used this product to retro-fit a thermal break on a door frame that was block and brick on both sides and the doorstep cavity had not been cleared of builders debris, which caused a wick of damp to enter the house.
Cut the block n brick out with a stone cutting disc, used my Titan SDS drill (from screwfix) to clean up.
Do your research on this product and make sure you are familiar with how it is fitted normally.
I removed the black triangles and shaved some of the foam off so it would fit in the gap ok.
In the end I removed the damp course strip and inserted that in between the brick and door frame by hand, then inserted the foam strip and fixed it in place with foam filler.
Final fill using hard wall was done 6 months later after thermal break was seen to be effective and water proof :)"
"At first glance it is not obvious how to use this product but a quick Google session reveals all. Contrary to the previous review, these are in fact designed for the cavity size specified - the DPC goes against the back of the outer skin, the insulation bridges the cavity to the specified width, and the clips fix the closer to the side of the inner block skin. If you want to look it up, this product is made by ybsinsulation and is called therma-close. Their website gives details of how to install it. Perhaps Screwfix could attach a copy to the product description here."
"For those familiar with this product the dimensions quoted in the product description are obvious. However, for those of us who are only occasional users it would be of great assistance if the product description showed all dimensions. It would then be more obvious that the smaller dimension of the expanded polystyrene foam is what goes into the cavity and that the 75mm, etc options that are available refer to DPC material attached to the foam."
"These do what they're supposed to do - building inspector was happy with the design and they fit into 100mm cavities OK. A bit pricey for what they are - simple enough to build your own from components - but if you've only a couple of windows to do, they're just the job."