New Build - first floor insulation query?

bouli73

Hi

Would be grateful for advice on what insulation should be used between joists on first floor of a new build? I have discussed with our builder and he has suggested either 150mm Rockwool or 200mm Fibreglass. The fibreglass option is cheaper but not by a substantial amount.

I would appreciate any advice on the above. I understand rockwool would have better sound insulation qualities but is there much of a difference between rockwool and fibreglass insulation otherwise?

Thanks in advance

MicktheMan

bouli73 wrote: »

Hi

Would be grateful for advice on what insulation should be used between joists on first floor of a new build? I have discussed with our builder and he has suggested either 150mm Rockwool or 200mm Fibreglass. The fibreglass option is cheaper but not by a substantial amount.

I would appreciate any advice on the above. I understand rockwool would have better sound insulation qualities but is there much of a difference between rockwool and fibreglass insulation otherwise?

Thanks in advance

What do you want the insulation to do exactly?

bouli73

Hi

I have been advised by my plumber and builder that it is probably more advisable to insulate between the joists on the first floor to improve the performance of zoned heating. The sound issue is not one that really concerns me and from what I understand, insulation would be of little benefit there in any event

MicktheMan

bouli73 wrote: »

I have been advised by my plumber and builder that it is probably more advisable to insulate between the joists on the first floor to improve the performance of zoned heating.

Having or not having insulation between your zones will have negligible effect on performance of zoned heating.

More importantly for you is what your airtightness strategy / target is.

fclauson

MicktheMan wrote: »

Having or not having insulation between your zones will have negligible effect on performance of zoned heating.

More importantly for you is what your airtightness strategy / target is.

And you overall insulation strategy

gman2k

I would be going for the rockwool option, purely for sound insulation purposes.