We have a garden room built on top of an old half-cellar (underground one side only due to slope). The floor is a concrete slab built on a steel girder framework inside the cellar and it is sucking all the heat out - leave the heating off overnight and it's down to single figures by morning.
A previous owner had studded under the floor and filled with glass-fibre but it had all gone wet and mouldy so we removed it. I was thinking about using PIR boards affixed under the concrete but was wondering if this might be a better place for spray-foam insulation. Seal in all the concrete and exposed metal, no gaps, no faffing installing the boards.
Is this technique used much in the UK - is it likely to be easy to find someone (not something I want to try DIY)? I know it's got mixed opinions for use in roofs or other places that need to be weatherproof.
A previous owner had studded under the floor and filled with glass-fibre but it had all gone wet and mouldy so we removed it. I was thinking about using PIR boards affixed under the concrete but was wondering if this might be a better place for spray-foam insulation. Seal in all the concrete and exposed metal, no gaps, no faffing installing the boards.
Is this technique used much in the UK - is it likely to be easy to find someone (not something I want to try DIY)? I know it's got mixed opinions for use in roofs or other places that need to be weatherproof.
