Removable Roof Insulation - Ideas

Dear insulation experts

I am new here and need expert advice:

Together with some friends, I want to buy and make habitable 3 old barns (so-called Rustici) in Ticino. Both the shell and the roofs of these Rustici consist exclusively of gneiss slabs. These roofs are extremely durable and stable, but individual slipped stones can cause them to leak. There are only a few specialized roofers left who are familiar with such roofs, but they can make them watertight again by carefully repositioning the stones. For this, however, they need to be able to look at the roof from the inside.
This brings me to our challenge: We want to insulate the roof from the inside, but preferably with a construction that can be removed relatively easily (in case something becomes leaky).

I am very grateful for your ideas. I have thought of the following:

- Clamp insulation mats between the rafters and thus directly under the gneiss slabs, then screw OSB boards onto the rafters (also as vapor barriers)

- Even more elegant would be to apply insulation directly on the OSB boards, then the whole construction could be removed at once. Which insulation material would you recommend for this?

What do you think of the idea? I am not an expert and therefore very grateful for tips!

Best regards

That is quite an ambitious task. I am not a specialist, but I would apply PUR rigid foam. This PUR rigid foam actually has good properties and is well suited for that.

Hello Roman Thank you for the tip! So something like that (see picture)?

Hi,

Yes, I would do it the same way as shown in the graphic. This PUR rigid foam is also a good solution. I also like working with it and it has several advantages.

Above all, the PUR rigid foam is waterproof and pressure-resistant.

Aha, thanks for your answer! I didn't know that it is waterproof! That would then have the positive side effect that you notice a leak faster, because the insulation material doesn't soak up water and rot first!

Hi,

Yes exactly, and that is correct. This PUR rigid foam cannot absorb water. It also withstands high temperatures because this PUR rigid foam belongs to the family of thermosets. Additionally, it has a high insulation performance.

So all good properties.