Is it 300mm or 200mm insulation in an attic????

paddy147

Just watching Eco Eye with Duncan Stewart on RTE1 at the moment.

He was interviewing the main man from Energy Action Ireland.They were talking about people who are in fuel poverty.

The main man says that they fit out all attics with 200mm attic insulation roll.It then shows the lads fitting a typical 3 bed semi d house attic out with 200mm insulation

I thought the thickness for insulating an attic was/is 300mm though???

heated

It's not really a question of 200mm or 300mm, instead what is is the thermal conductivity (K value) of the material being used. The building regs allow for an average heat loss (U value) for ceiling insulation of 0.16 W/m2. Typical loft roll has a k value of 0.044 W/mk. This equates to a U value of 0.147 W/m2 with 300mm thickness which exceeds the requirement and therefore complies with regs. If only 200mm of this material was used the U value would be 0.22 which would not comply. That said there are loft insulation materials available which will achieve the required U vlaue in 200mm or less.

Hope this helps.

paddy147

heated wrote: »

It's not really a question of 200mm or 300mm, instead what is is the thermal conductivity (K value) of the material being used. The building regs allow for an average heat loss (U value) for ceiling insulation of 0.16 W/m2. Typical loft roll has a k value of 0.044 W/mk. This equates to a U value of 0.147 W/m2 which exceeds the requirement and therefore complies with regs. If only 200mm of this material was used the U value would be 0.22 which would not comply. That said there are loft insulation materials available which will achieve the required U vlaue in 200mm or less.

Hope this helps.

Dont remember the chap saying anything like that to Duncan.

He just said the people who were in fuel poverty could apply for and avail of this service from Energy Action Ireland and that they install 200mm of rolled insulation.Thats all that was said.

Oh and the insulatiion was yellow in colour.

heated

200mm is better than none at all!

paddy147

Its on RTE Player.

Look at this evenings Eco Eye and got to 20 minutes into the video and listen to what he tells Duncan.The scheme is open to people who fall into the terms of the "Fuel Allowence Scheme".

Insulation is Moy Isover 200mm


http://www.rte.ie/player/#!v=1131423

heated

The regs do also allow for the loft insulation to have a value of 0.3W/m2k provided that the combined U value of all elements of the ceiling and roof (ceiling plaster board, loft insulation, air void, roof felt, roof tiles and surface resistance) achieves the 0.16W/m2k standard. This would need to be calculated for each installation. Easier to just fit the 300mm of standard loft roll me thinks

paddy147

heated wrote: »

. Easier to just fit the 300mm of standard loft roll me thinks

Alot less hassle and cheaper too.Thanks.:)

brophis

I watched that episode too, wasn't there already some existing insulation in place under the new stuff? This would increase the overall u-value

paddy147

brophis wrote: »

I watched that episode too, wasn't there already some existing insulation in place under the new stuff? This would increase the overall u-value

Yes there was,but the fella from Energy Action said that they install 200mm insulation into the homes for people on this scheme.

It just struck me as odd,when I read everywhere else that it usually is 300mm in an attic.