Fire protection for wood

Hello everyone,
I have the following problem. We have set up our model railway layout in the attic at my parents' house. It is quite large and even has 2 levels, which is why there is a lot of electronics and electrical wiring installed there.
Anyway, the attic is quite old and not really finished. You can only see the large wooden beams and above them are the roof panels/roof tiles.

Now my question is, in the worst case (which hopefully will never happen) if something in the electrical system burns out or the layout starts to catch fire for some reason, how can I best prevent the entire roof structure from burning down?
Can the wood itself be protected with some kind of treatment or do you almost have to rely on a fire suppression system?

Thanks in advance for the help!
Best regards :rolleyes:

I would simply use a fireproof surface and remove the fuse when no one is around.

So the substrate is less of a problem since the floor apparently consists of concrete or screed, in any case it is fireproof. The problem is the roof with the large wooden beams, so if something starts to burn, it could spread to the wooden beams.

Unfortunately, there are no fuses upstairs, we will probably install a circuit breaker soon but often my niece or my nephew play there. If they possibly forget to turn off the power or maybe spill water on it or something similar, you never know with children, then I want to play it safe at least.