Drywall needs replacing due to water damage help!

[Jimmy9876]

Had a leak from ensuite, found lots of mould when tiles & plaster boards removed. Decided to replace all damaged materials, incl.part of the drywall on three sides all the way from floor to ceiling. Is it ok to cut half of the drywall off? I mean is it going to be solid enough if the framework top and bottom are then several separate timbers, as opposed there's just one long one on each side where the drywall originally is built on? See my pic with the red arrows, going to remove these and then cut like the green lines are...

Going to put moisture boards. How to make the corners etc watertight? How can you be sure they don't move? Should the moisture boards be tanked? What's the best stuff to do it with? Don't want this disaster to happen again where the corners leaked and caused a lot of damage.

Also floor timbers under the chipboard are mouldy. Is it ok to cut say 5 cm deep part off the timbers and put some clean wood there? Is the structure still going to be solid? We're talking about 2 timbers, which are damaged to approx 40cm damage about 3 cm deep. They're running just outside the ensuite where the water leaked.

Due to health issues these mouldy materials need to be removed rather than just washed/treated...
hope someone can help, thanks!
First post so sorry if in wrong area!

 

[foxhole]

Is it a how're enclosure?

 

[Jimmy9876]

It's ensuite bathroom on 1st floor, all walls are internal

 

[vinn]

Use a small screwdriver to probe the studs and plates - if its spongy and crumbing (ie its wet rotted) then come back here.
But, typically, you can simply scrape off the mouldy stuff, and treat with creosote or similar.
Use a 6" paint brush to soak everything including the chipboard.
I dont think its any big issue and certainly not structural.

Do you know why the compartment leaked?
Perhaps a pic of the whole compartment might help?
Its best practice to use backer board not drywall for tiling wet areas - whatever, dont go back on with plaster board.
The copper pipes look to be loose - are they clipped, and dont rattle when the s/valve is used?
You need an extra stud or backing at inside corners - each board needs 40m of bearing.

 

[Jimmy9876]

Thanks for your reply mate.

Apparently the corners leaked, silicone maybe, although there was nothing visible on the tiles or silicone, no mould spots. A bit of a mystery...
I don't know about the pipes, haven't noticed any rattling... will make a note of that
Will make sure there's extra backing at inside corners when fixed. Thanks

I've put a pic here about joists under floor, couple are mouldy, and was soft when discovered but seems drier now as house is quite dry. What do you recommend? Not totally happy about leaving them there as they are.
Would it be ok to cut the mouldy areas off? Would it still be sound? Talking maybe 1 or 2 inches off.
The depth of the mould damage is about an inch

 

[endecotp]

No, you cannot slice two inches off the top of your floor joists. They will lose a lot of their strength.

 

[vinn]

The joist in the pic appears to need a section cutting out, and treating with the above chemicals - perhaps the other joist(s) needs such treatment.
Sister a ripping of 22mm ply as a screwed on reinforcer - or even a short length of screwed on 2" x 4"

Is the chipboard showing fungal damage - you can cut a section out, and give some backing to a replacement piece with a couple of noggins. All edges must be supported.

Ref the framing: you will probably need an extra stud at the point where the backer board changes to drywall - usually just beyond the enclosure jamb/standard. What you are looking for is the shower wall tile to end just beyond/outside the enclosure.