Roof insulation of a barn rarely heated

Hello everyone,

I have a small barn from 1980 with a floor area of 10mx10m. The barn has no intermediate ceiling and an Eternit roof covering.

The barn is now to be used as a hobby workshop and should therefore be heated occasionally. (tendentially only on weekends or after work)

However, heating makes little sense with the Eternit roof covering. Therefore, a roof insulation is being considered. Since, as mentioned, heating is only done rarely, I fear that the insulation might get saturated and I could get mold.

My question: Does anyone have experience with a similar case? Can my concerns be shared or are the fears possibly unfounded?

What is the best insulation for this problem?

Thank you in advance.

Hello

Barns usually have only a wooden board wall or something similar. At least mostly nothing that comes close to thermal insulation. They are also often quite drafty.
Add to that an area of 10x10m and how high is the barn?
That adds up to quite a volume. Heating all that up after work and doing it again every few days, I don’t know...

Which insulation is best depends on how the roof is constructed. If there are many corners and beams, then at least glass wool, probably better a blown-in insulation.
There are insulation materials that are not so sensitive to moisture, I just don’t remember what they are called right now.
Unfortunately, I also cannot say if these are solid, soft, or loose.
And then there is the question of what happens to the condensed moisture; if it repeatedly settles on the wood, that’s not ideal either.
Just based on the floor area, this will be quite expensive, I’d estimate thousands of euros.
Can the roof also bear the additional weight of the insulation when a once-in-a-century winter comes again…

What are you doing in the barn? Maybe it’s better to build a second room inside the barn, for example 5x5m with a simple ceiling. That could be done with wooden studs, interior OSB panels optionally with an insulation layer.
Add a simple workshop stove and that’s it.
Then maybe you don’t even need thermal insulation because the stove has enough heating power to continuously keep a smaller room warm, and the mess with vapor barrier and mold won’t be a problem anymore.