Prepping bathroom floor and walls

[phil w]

Hi Guys
Could you give me a bit of advice.
redoing bathroom in 305x405x12mm (18"x12" in old money) travertine floor and walls (full height)
floor size is 2.4m x 2m walls 2.4h
18mm t&g chipboard floor down at moment wet around bath area so the lots comming up and binned. While floor is up will put 3x2 noggings in to be on safe side for what it takes, then thinking along the lines of 18mm marine ply screwed at 150mm centres flexi adhesive then hardieboard screwed 150mm centres on top (when screwing the hardieboard down does it have to go through ply and into joists or can it be screwed basically where it falls into ply ? if you get my meaning)

Walls have been half tiled and top half new plaster new plaster has had diluted coat of emulsion and one coat on top of that still see dark plaster in places so not much paint on it, question is old tile area will get replastered will need priming what type of primer ? does painted plaster need scraping over to allow key for addy then priming, don,t want to get full room replastered if can help it.
going to put metal stud wall up to hide pipes and fix shower too 1400mm wide x 2400mm high with 150mm return, will the wall be strong enough to take tiles if I fix hardiebacker direct to stud or should plaster board then h/backer on top or open to suggestions concerened about weight of tiles on stud wall

Sorry for going on a bit last one, any of the guys in north east stockton,m/boro, hartlepool area advise on best place to buy h/backer and addy thinking of using a Mapie flexi seems popular with you guys so good enough for me, not working at moment xmas on the way so anything I can save on prices of materials a big help
Thanks Guys
Phil

[Alan.P]

Hi Phil, floor sounds about right, as for walls, the plaster will not take the weight of the Trav, you'll need to overboard the plaster or strip back and board it with the Hardie or other cement board. As for a supplier, CTD on Portrack.

Sorry for the quick answers, long day and bed time lol, others will have more to say