Floor screed

[willismp]

Hi,

We have a block and beam floor in a new extension, the drawings state 75mm insulation, 65mm screed.

The screed companies I have spoken to suggested 40mm liquid screed, 100mm insulation.

This seems very thin to me its a large area 89 sq meters, and I do not want cracks!

thanks

 

[Jason1790]

Hi,

We have a block and beam floor in a new extension, the drawings state 75mm insulation, 65mm screed

If you have a full plan application then that's what you have to use.

40mm seems very thin, especially over such a large area, but how good are the company? They should know what they're talking about so perhaps 40mm will do? I don't think UFH would be a good idea in such a thin screed either, so you would have to consider that as well. Personally I'd use the 65mm screed.

 

[freddiemercurystwin]

Hi,

We have a block and beam floor in a new extension, the drawings state 75mm insulation, 65mm screed

If you have a full plan application then that's what you have to use.

40mm seems very thin, especially over such a large area, but how good are the company? They should know what they're talking about so perhaps 40mm will do? I don't think UFH would be a good idea in such a thin screed either, so you would have to consider that as well. Personally I'd use the 65mm screed.

No, you don't have to stick with the drawings that were approved.

Anyway the insulation needs to be thick enough to meet the regs and that depends on the type of insulation proposed and the perimeter of the extension. With regards to the screed 65mm is about the minimum for a conventional screed.