UFH.....Celotex or 200mm of roll insulation ??

[aspley]

Hi Guys.......advice please on which is best for insulation under first floor UFH 60mm of Celotex or 200mm of a roll insulation.

Cheers

 

[JohnD]

sound or heat?

 

[aspley]

Err...............heat. Where does sound come into it?

 

[Dan Robinson]

Document E of the Building regs.

 

[aspley]

Geeeez.......this is hard work..........all I'm asking is 60 mm Celotex or 200mm of roll insulation........simples

 

[Dan Robinson]

75mm celotex .

 

[aspley]

RTFQ?....for reasons I won't begin to explain 75 mm not an option

 

[JohnD]

fibreglass then

Celotex is a better insulator, at the same thickness, but not so much that it will be as good as 200mm.

 

[Dan Robinson]

2 x 100mm celotex then .

 

[ALEC1]

Under a slab of concrete? it has to be celotex...

Rockwool can be used under spreader plates in timber floors though..

 

[aspley]

Thanks Guys for your comments......i really needed confirmation that roll insulation at 200 mm would not compromise the job. To be honest roll is quicker and cheaper (£1000 cheaper) but I did not want to be swayed by the price.

 

[DeltaT2]

Glass wool is much, much cheaper & best installed on top of ground floor ceiling before the UFH system is fitted. Last job we done we fixed 'netlawn' to the ceiling joists before we fixed the plasterboard ceiling, for a couple quid it's a much better job.

 

[Agile]

What floor/ceiling construction benefits from net lawn?

The OP is not being very informative. A curious mind like mine then wonders how 200 mm of glass fibre is possible but not 75 mm of cellotex!

Tony

 

[JohnD]

obstructions between the joists perhaps? herringbone, nogs, pipes, cables?

so far he has not asked if it is acceptable to put thermal insulation on cables, and what will happen if he does.

 

[DeltaT2]

What floor/ceiling construction benefits from net lawn?

The OP is not being very informative. A curious mind like mine then wonders how 200 mm of glass fibre is possible but not 75 mm of cellotex!

Tony

Tony the netlawn can be fixed in such a way that it keeps the insulation clear of cable/noggings-dwangs etc. & fully supports the insulation prior to plasterboarding.

Depending of course on the type of UFH system, this will determine the type & size of insulation. A first floor 'pug system' will take up more joist space than plates.