Block and Beam No insulation why???UFH etc....

14 Nov 2011
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United Kingdom
Can anyone advise my house was built in 2000 and I'm in the process of having a rear extension built today the builders have started to construct a pad stone for a Steel Column to sit on. Down so they have broken through the old block and beam floor and to my Surprise and my builder the Floor Construction on my existing house is only and 350mm map then block and Beam a dpm then 40mm of screed!!!! no insulation at all I have always wondered why my feet are so cold in the winter standing on the tile floor. now the plan was (now this was a plan now re-evaluating lol)to remove all the old screed and insulation we expected it to me very poorly insulated. The new celotex and underfloor heating wet system then screed over the top. The floor is to be tiled once extension is completed. Can anyone advisehow I can insulate the old floor it needs some form of insulation for sure? And anyone advise on the Under floor heating ideas? Ive attached a picture for you all to see

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Oh dear, non compliant....I bet there was a requirement in b/regs in 2000 for a bit of insulation.

If you are wanting UFH as primary heat source, I wouldnt bother unless you can achieve at least 50mm pir insulation.

You will be disappointed if you do.
I have 350mm gap underneath the block and beam floor the ground is hard and feels like compacted type 1/concrete. I can get underneath the whole floor If I were to insulate the floor from underneath with 150mm Celtoex boards and seal up all the joints so it would provide a complete sealed area would this make the floor feel warmer in the winter?(As I don't think I could cope with the floor being that cold next year)
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I can get underneath the whole floor
How, if you only have 350mm?
If you really can great, if not get a quote for full fill Eps beads, just watch ventilation.
If you removing the screed, then some of the rows of blocks could come up for access.

Insulating below block and beam will be tricky.

Dont forget it will fall under building regs, so you may be best to seek advice from the inspector. Or redo the floor completely without his knowledge.....

There will be some thermal bridging from where the beams rest on the inner blockwork, which is is sitting on the foundation.

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