Hello everyone,
I am currently considering whether to insulate our cold roof or not (it’s just a storage room).
Our house was built according to the KfW55 2016 standard (completed mid-2018) and therefore has insulation on the cold roof / upper ceiling of 240mm (9.5 inches).
Under the roof tiles, there is a vapor-permeable membrane installed.
My idea was to insulate the roof to save heating costs and to avoid extreme temperatures in the storage room.
The rafters are 240mm (9.5 inches) deep except for the dormer, which is “only” 140mm (5.5 inches).
Here are my questions:
Is it even worth it?
The roofer said, “If it were mine, I would do it.”
The construction manager thinks the costs would not be recovered.
What is your opinion?
Regarding the insulation itself… I assume it only makes sense to insulate the entire roof at the same thickness, right?
I do not want to install additional battens on the dormer, so would it be reasonable to insulate the entire roof to 140mm (5.5 inches)?
If yes, for the 240mm (9.5 inches) rafters area, should the air layer be between the insulation and the interior room or between the insulation and the roof? After the insulation, I would add another vapor-permeable membrane.
Is there anything else to consider?
Thanks in advance.
I am currently considering whether to insulate our cold roof or not (it’s just a storage room).
Our house was built according to the KfW55 2016 standard (completed mid-2018) and therefore has insulation on the cold roof / upper ceiling of 240mm (9.5 inches).
Under the roof tiles, there is a vapor-permeable membrane installed.
My idea was to insulate the roof to save heating costs and to avoid extreme temperatures in the storage room.
The rafters are 240mm (9.5 inches) deep except for the dormer, which is “only” 140mm (5.5 inches).
Here are my questions:
Is it even worth it?
The roofer said, “If it were mine, I would do it.”
The construction manager thinks the costs would not be recovered.
What is your opinion?
Regarding the insulation itself… I assume it only makes sense to insulate the entire roof at the same thickness, right?
I do not want to install additional battens on the dormer, so would it be reasonable to insulate the entire roof to 140mm (5.5 inches)?
If yes, for the 240mm (9.5 inches) rafters area, should the air layer be between the insulation and the interior room or between the insulation and the roof? After the insulation, I would add another vapor-permeable membrane.
Is there anything else to consider?
Thanks in advance.
Forget it!
You won’t save on heating costs with this; rather, you’ll likely increase them because you’ll end up heating the previously unheated roof space without improving the insulation from the outside. Does your heating system even have the capacity to handle the additional volume?
On top of that, you’ll face issues with the vapor barrier, which would somehow need to be connected to the existing one in the upper floor area for this plan.
In summary: financial costs, labor time, high risk of damage, and as a result, even higher heating expenses.
Such a measure might be worth considering if it created additional living space, but certainly not just to make a few boxes and old furniture more comfortable. Ideally, this kind of extension should be planned and prepared during the initial construction. If you’ve missed that step, it’s usually difficult or even impossible to carry out the project properly.
You won’t save on heating costs with this; rather, you’ll likely increase them because you’ll end up heating the previously unheated roof space without improving the insulation from the outside. Does your heating system even have the capacity to handle the additional volume?
On top of that, you’ll face issues with the vapor barrier, which would somehow need to be connected to the existing one in the upper floor area for this plan.
In summary: financial costs, labor time, high risk of damage, and as a result, even higher heating expenses.
Such a measure might be worth considering if it created additional living space, but certainly not just to make a few boxes and old furniture more comfortable. Ideally, this kind of extension should be planned and prepared during the initial construction. If you’ve missed that step, it’s usually difficult or even impossible to carry out the project properly.
S
Schlenk-Bär30 Dec 2018 07:47Dr Hix schrieb:
You won’t save on heating costs with that; rather, you’re likely to increase them because you’ll end up heating the existing ventilated roof space as well, while the external insulation does not improve. Why does he have to heat that as well?
Similar topics