Counter battens in the interior area for roof insulation

Hello,

According to the statement from Isover, the underspar insulation can be used without concerns in my case.

The underspar insulation also has the advantage that the rafter beams, which are only insulated on the sides, are insulated on the front side by the additional insulation.

I informed the service employee that opinions in a forum regarding the insulation differ with various reasons.

The additional insulation also would have no negative effects regarding condensation, etc.

One more thing about the construction of my foil, since the load-bearing capacity of the battens is being discussed here:

In the upper area of the roof slope, I installed the foil longitudinally along the rafter beams. Roll width of the foil 1500mm, then cut to 600mm (rafter spacing).
Due to the "short" 1500mm strips, handling was easier (I am doing this alone).
I cut out the collar beams and glued them at the end.

Afterwards, I installed a complete strip longitudinally along the rafters. This saved me a lot of gluing and I didn’t have to cut too much.

I closed the knee wall connection with 2 strips measuring 1500 x 350 mm.

Then I measured the distance between the collar beam and knee wall and divided it into 7 equal sections.
I then come to an internal dimension of 26 cm and thus a center-to-center distance from batten to batten of 28.4 cm.

For my first slope, I took a 600 mm measure which was not optimal. -- Learning by doing --

Here is a picture: (Red border shows the installation method)

Were there possibly any indications regarding the mechanical securing of the adhesive joints using pressure strips or did the expansion loops of the foil play a role in the conversation with the manufacturer concerning the durability of the (to be executed without tensile forces) adhesive joints?

@Venice

The insulation under the rafters would also have the advantage that the rafter beams, which are only insulated on the sides, are insulated on the front side by the additional insulation.

How wide are your rafters? I would have guessed about 8cm, so minus the 5cm of the batten, about 1.5 cm next to the batten for the under-rafter insulation on the front side. Okay, something new every now and then.

The additional insulation would also have no negative effects regarding condensation, etc.

Nothing better can happen to you. I would save that email well, because with it you have good protection, even in the new construction state, i.e. with increased water vapor and the sd values in your case.

What more do you want,...

Best regards