As long as you look after them properly no problem.

We have wooden floorboards in our bathroom, in fact over most of the house due to carpet allergies. It's been "mostly" fine. We had visitors who let the shower play out over it for a while, it seeped through the cracks and stained through the plasterboard ceiling below. Other floor coverings would have probably avoided the issue. We let the plasterboard dry, painted with oil paint then emulsion, all fine. Just using emulsion alone often stains again.
Have always used diamond hard satin varnish, never really looked into different oils/waxes. I like that it doesn't smell much when you use it. It doesn't mind getting wet, it always wears out in hallways first due to traffic.

Personally, I don't find anything about softwood flooring particularly sensible, in what in the 21st. century really should be a wet room.
Line the floor with T&G plywood, and seal both floor and partway up the walls with appropriate wetproofing membranes. Then apply any one of a number of different waterproof coverings, even ones that look like pine floorboards. Recycle the softwood into something else.

Posted By: owlmanPersonally, I don't find anything about softwood flooring particularly sensible, in what in the 21st. century really should be a wet room.

😁😁😁

Define a wet room please.

Was the particle board blown, because water got past the sealing/tanking?

That's what happened to us, v messy and disruptive.

Kristeva's idea is good, as the wood is on display and cannot sit wet and rotting unseen. But consider where any water leakages would end up.

Posted By: RobLWe have wooden floorboards in our bathroom, in fact over most of the house due to carpet allergies. It's been "mostly" fine. We had visitors who let the shower play out over it for a while, it seeped through the cracks and stained through the plasterboard ceiling below. Other floor coverings would have probably avoided the issue. We let the plasterboard dry, painted with oil paint then emulsion, all fine. Just using emulsion alone often stains again.
Have always used diamond hard satin varnish, never really looked into different oils/waxes. I like that it doesn't smell much when you use it. It doesn't mind getting wet, it always wears out in hallways first due to traffic.

Yes, I'd imagine varnish acts more as a sealant than wax?

Waxing the floor would certainly make the bathroom installation a lot easier lol

Posted By: owlmanThe sealing/tanking is fairly easily achieved with modern products if they are carefully applied.
On suspended floors I always make sure the joists are tight and any "bounce" is eliminated. IMO, only use plywood as a sub base, in the past after sorting out "blown" particle board floors in bathrooms, I only ever use ply on such floors.

Does your definition of particle board include grade 3 OSB or are you referring to the various grades of chipboard?

For plywood I presume you mean WBP ply or the modern equivalent.

Ah Peter, WPB, AKA, Weather and Boil proof, actually as you allude, no such animal, dead and gone, even though some suppliers still refer to it. If a builder/contractor refers to it in some spec. sheet the alarm bells should ring.

These are I believe the current plywood standards:-

https://apawood-europe.org/official-guidelines/european-standards/individual-standards/en-314-2/

As for particle board in bathrooms, I only have had, " bad" experience with chipboard.

Peter,

OSB 3 is very water tolerant in my experience. Treating cut ends might be a good idea if critical.
Spec says humid conditions rather and protected from direct water.

I put down an 9 mm (I think) over old floorboards in my bathroom to give a good flat floor to work off.