new build bathroom floor advice

[scooby9858]

hi everyone i could do with a bit of advice.i am not a tiler but have done tiling before.i am tiling a bathroom floor for a relative in a 10 year old new build.normally i would replace the chipboard with ply.but this house has i joist system like the one in photo.i dont want to cut up the chipboard as theres pipes everywhere.the bathroom is upstairs.walking about upstairs theres creaking in the top hall bathroom and the two rooms either side of the bathroom.i put a glass half full of water all round the bathroom floor and jumped.i didnt see any movement in the water so god knows where the creaking is comming from maybe the kit has moved.the tiling is 1.6m x 2m what do you think.thanks

 

[macten]

If the joists look like that then the creaking could be coming from anywhere!!! and you'd expect it. Main thing is you've checked and deduced the floor is solid with no discernible movement so I would overboard with cement board and tile (and be prepared to live with the squeak which may still be present after tiling)

 

[One Day]

Such a small area, I'd suggest overboard with 10mm wedi board or even hardibacker (there i said it). Better than tiling direct to chipboard, although if you fancy life on the edge you could use tilemaster Ultimate straight into chipboard.

 

[scooby9858]

thanks lads 6mm hardiebacker it is then.will let you know how i get on.

 

[One Day]

thanks lads 6mm hardiebacker it is then.will let you know how i get on.

Just don't breathe in the dust from hardibacker! 🙄

 

[Flintstone]

Hardie deffinately better than insulation in this instance. Remember to stick it

 

[Bond]

Creaking chipboard flooring, not unusual, l would pour glue or SBR into joints in the flooring before overboarding, and force adhesive in also.

 

[JerryB]

Is the chipboard nailed to the joists? I'm sure this is the source of the fire-cracker style creaking in our house. I plan to replace the nails with screws. Ideally remove the nails but thats not easy if you want to avoid digging a hole around the head of each nail

 

[scooby9858]

you were right Jerry heres a wee update i wasnt happy with the creaking so i decided to lift the floor.22mm chipboard on top not screwed or nailed no wonder it was creaking.underneath was like 12mm sterling board nailed to joists with staples.so not very good at all.
so all joists have been strengthened and 18mm wbp fitted floor tiles will be 8mm thick that will leave a 8mm make up would that be ok to use a thick bagged flexible adhesive?also the wall tiles are ceramic 300 x 300 x 8mm. around the bath area i was going to use tubbed mapei ultimate showerproof adhesive.then for the non wet area Mapei Trade Super Grab Tile Adhesive 15kg Off White - Toolstation - https://www.toolstation.com/shop/Painting+%26+Decorating/d150/Tile+Adhesive+%26+Grout/sd3107/Mapei+Trade+Super+Grab+Tile+Adhesive/p36270 thanks again for all the help