There are various types of underfloor heating (UFH) that can be installed on top of a joisted wooden floor, but a traditional screed system is not one of them. The most likely reason you have been advised against this is due to weight, which could cause structural issues – a screed system would be a very heavy weight for the floor to bear. You will also lose a good deal of floor-to-ceiling space.

If you are aiming to create a fluent floor level running throughout the existing bungalow and into the new extension, it would be best to look at the retrofit UFH solutions on the market. The majority of retrofit systems work well with both concrete and joisted floors, offer minimal height build-up and can be installed to maintain the same floor level if needed. You will need to insulate underneath the floor deck to avoid losing any heat downwards due to the air void.

Every project is different, so if you aren’t sure about the most suitable solution for you, it’s always worthwhile calling a UFH supplier as they can talk you through the various options.

Heather Oliver, Product Development Manager at Nu-Heat