ᐅ Insulating a Roof with Thermal Conductivity Class 032 or 035?, 180mm Mineral Wool
Created on: 27 Apr 2012 12:01
J
jonny666111
Hello,
I have received a quote for insulation using 180mm (7 inches) mineral wool with a thermal conductivity of 0.035 W/(m·K). Now I am wondering if using 180mm (7 inches) with 0.032 W/(m·K) would be more effective and if it would be cost-efficient.
I have already experimented a bit with a U-value calculator and quickly got a U-value of 0.20 and 0.18 with 0.032 W/(m·K).
Would this difference be significant or noticeable?
The roof structure is planned as follows from inside to outside:
12.5mm (0.5 inch) gypsum board (possibly double) – 30mm (1 inch) insulation below rafters (if useful), otherwise just battens for installation level – vapor barrier (airtight layer) – 180mm (7 inches) insulation between rafters – underlay membrane – roof tiles.
What would you suggest? Most of my research only compares different thermal conductivities with regard to material thickness. I haven’t found any cost advantages.
Regards, Jonny
I have received a quote for insulation using 180mm (7 inches) mineral wool with a thermal conductivity of 0.035 W/(m·K). Now I am wondering if using 180mm (7 inches) with 0.032 W/(m·K) would be more effective and if it would be cost-efficient.
I have already experimented a bit with a U-value calculator and quickly got a U-value of 0.20 and 0.18 with 0.032 W/(m·K).
Would this difference be significant or noticeable?
The roof structure is planned as follows from inside to outside:
12.5mm (0.5 inch) gypsum board (possibly double) – 30mm (1 inch) insulation below rafters (if useful), otherwise just battens for installation level – vapor barrier (airtight layer) – 180mm (7 inches) insulation between rafters – underlay membrane – roof tiles.
What would you suggest? Most of my research only compares different thermal conductivities with regard to material thickness. I haven’t found any cost advantages.
Regards, Jonny
J
jonny6661112 May 2012 13:22€uro schrieb:
In this case, I guess there’s no need to calculate. A U-value of 0.17...0.18 will definitely have a positive effect when using pellets.Is that meant ironically?
I ran these calculations again using the U-value calculator.
Due to the dew point, only 3 cm (1 inch) of insulation below the rafters is possible.
032 WLG without insulation below rafters -> U-value 0.21 -> 1178€
035 WLG without insulation below rafters -> U-value 0.22 -> 786€
035 WLG with 3 cm (1 inch) insulation below rafters -> U-value 0.19 -> 1300€
So, could a professional give me a decisive recommendation for one of these options? Or?
I can’t quite interpret the last reply.
Regards, Jonny
Similar topics