Pitched roof insulation

Hello everyone,

we are currently in the process of looking for a property developer and have two in the final selection. Now I would be interested to know which of the roof variants is better?

One offer is
Wooden beam ceiling with wooden boarding - insulation between rafters + counter-rafter clamp felt 40mm

the other
Roof structure with insulation between rafters + Pavatex boards (25mm)

Are there any differences?

Thank you very much for the help
Markus

Hi Markus, from an insulation technology standpoint the second variant is to be preferred because it is a very diffusion-open construction. Statistically, the first variant is stronger because the wooden cladding has a bracing effect.

The question is, what is needed...?

Best regards

Susanne Junghans

Hello Susanne,

thank you very much for the feedback. For me as a layperson, the insulation is the most important, as I assume the statics have to fit ;-) although I am very interested in both thermal and sound insulation.

I have received a few more pieces of information on the two points.

One offer is
wood beam ceiling with wooden paneling - insulation between rafters + 40mm sub-rafter insulation felt
- Kalzip roof

the other
roof structure with insulation between rafters + Pavatex boards (25mm)
- roof covering (trapezoidal sheet)
- laths
- counter laths
- Pavatex wood fiber underlay board approx. 25mm
- insulation between rafters 200mm (insulation felt)
- vapor barrier and airtight membrane
- laths
- interior cladding

Could you possibly let me know if this is also optimal from the thermal and acoustic engineering point of view for a shed roof? Or what could still be improved (e.g. thicker Pavatex)?

Thank you very much for your help
Markus

Hi Markus, the second construction is correct and works like that. One small note: the Pavatex (25mm) may only be used as an underlay board down to a certain minimum slope. You can call Pavatex and check if that fits.

The first construction unfortunately does not provide any precise indications, it may be okay or equivalent, I can't tell like this. Please also give me the exact insulation thickness and insulation material, then I’ll gladly write something about it again.

Best regards

Susanne Junghans