ᐅ Fire Protection for Wood

Hello everyone,
I have the following issue. We set up our model railway layout in the attic at my parents’ house. It is quite large and even has two levels, so there is a lot of electronics and electrical wiring installed there.
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.

My question is, in the worst-case scenario (which hopefully will never happen), if something in the electrical system shorts out or the layout catches fire for some reason, how can I best prevent the entire roof structure from burning down?
Is it possible to protect the wood itself with some kind of treatment, or would it almost require a fire suppression system?

Thanks in advance for your help!
Best regards 🙄

I would simply use a fireproof base and turn off the circuit breaker when no one is around.

So the substrate is less of an issue since the floor seems to be made of concrete or screed, in any case, it is fire-resistant. 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 circuit breakers upstairs yet. We will probably install a circuit breaker soon, but my niece and nephew often play there. If they happen to forget to turn off the power or maybe spill water on something or similar—since you never know with children—I want to be on the safe side at least.