Wet room shower tray.

[Getting started.]

Is there any reason why I can’t fit a 30mm Orion shower tray directly too my floor boards then build the rest of the bathroom up with 30mm ply

my issue is my floor boards run right through under my walls, so cutting out the square and then fixing the boards which are not close to a joist will be much harder. All the videos I see the floor boards end at the wall.

 

[23vc]

Wet room - why are you fitting a tray? Do you mean former which you then tile over?

 

[Getting started.]

Yes

 

[23vc]

All depends how sound and level the boards are. If they’re sound, then you may be ok to do as you suggest. I’ve had similar on 60s houses with partition block work walls built off the floorboards. Like you say, you can’t remove the boards easily. I’d still remove as much as you can back to the nearest joists, and replace the rest with ply. Add loads of extra screws too.
Doing as you suggest also means there will be a step up at the door threshold.

 

[Getting started.]

Ye I don’t mind the step up to be honest it’s usual in oz where I was living I would try to slope from the door a little in.

Actually the boards are really solid because they go through but what you would recommend where the tray former is sat is to cut out the floor boards to the joist then add the cross noggins (shown on installation vids) then ply in the hole making sure it’s sturdy then tray former then ply the rest of the bathroom?

 

[23vc]

Yeah, I’d only leave the bare minimum of original boards, and do the rest properly.

 

[Getting started.]

Thanks mate. When I finally measured it the drain falls on a joist so I have to move the shower tray out from the wall a little which means I don’t have the problem.

 

[Madrab]

I wouldn't recommend it.

If I was fitting a former like that, and it was to be laid flat to the floor, then I'd be constructing a subfloor that is solid as a rock, so it won't move much later down the line (apart from natural expansion that can't be avoided).

Ideally cut the floor boards out (use a plunging circular saw), where you will be placing the former, then you fit noggins/dwangs/supports across/along the joists and create a square lattice, you then fill in the spaces level between the joists with 18mm ply/floor board so you have a solid level subfloor to place your former on. That would then be topped with 3mm WBP ply screwed at 100mm spaces and then tank/waterproof it.