A dilema.

[Rob01]

Hi,

I posted a thread yesterday about whats better to use ply or backer boards this is sort of to do with that but not. My dad has 2 bathrooms that need floor tiling both upstairs only a 2 year old extention the floors are chipboard flooring all solid etc. All bathroom appliances have been fitted and lino for the covering of floor. but he now wants it all tiling trouble is the fitted units etc in the bathroom are going to be a nightmare to get out nevermind putting back. my main concern is preping to tile for example,

Does a ply or backer board base need to be layed over the chipboard? problem witht this would be the untis are in the way so cant get under them, or is there an alternative of laying over the chipboard with out these and tiling up to units, toilet, basin etc...

Thanks rob.

[blocko]

Yes, it could easily be done and IS recommended, but not essential (I never tile onto chipboard....ever!!!) . The problem with not doing it is that if the joists arent braced (noggins spanning between them to strengthen and reduce deflection) then the tiles/ grout may crack. Oh, and chipboard swells and causes all sorts of horrible nasty problems

Hope this helps!?!?!

[Rob01]

so to lay straight onto the floor would be fine and go upto units etc? is there prep needed on the floor maybe a pva mix or a prima? thanks

[blocko]

Oh, if you do go ahead and do it just make sure you know where ALL cables and pipes are....... for the second time this year again tonight I came within 5mm of screwing straight through a 15mm copper pipe under a floor......... I was tired and totally ignored my own markings on the flooring where all pipes and cables were!

[timeless john]

NO you cannot lay tiles straight onto chipboard!

[blocko]

Sorry Rob, didnt see you just replied again........ thoroughly clean, then prime the substrate (floor) with a primer such as primer-g or an sbr primer. The backer boards are then laid in a staggered fashion over a flexible cement based tile adhesive (this will take out any voids between layers). I always go for a 10mm solid bed trowel. Then screw backer board down at recommended intervals (usually minimum 300mm, but I go for 200mm) whilst tile adhesive still wet. Watch all levels constantly using a decent spirit level.


Never, ever use PVA..... just type PVA into the search facility on this site to see why!

so to lay straight onto the floor would be fine and go upto units etc?

I would definately overlay with 18mm ply or backerboard.......DO NOT tile straight onto chipboard floor!!!

[Rob01]

ok thanks alot for the advise big help my only question now is getting around units, toilet and basin as they cant really be taken out to lay on?

[blocko]

Just cut around them using suitable tools, then silicone the gap (once tiles laid) to leave a nice clean finish!

[Brinkley]

pinchers

[Rob01]

ok i spose the only thing will be the height up the units buts it not going to be massive so i supose it will have to do i imagen you must get these jobs doing it day in day out?

[kevg]

ok thanks alot for the advise big help my only question now is getting around units, toilet and basin as they cant really be taken out to lay on?

I probably shouldnt be giving advice as I am not a professional tiler, but there is a great little tool I have seen in my travels to give you fairly accurate cuts when going round toilet and basin etc if you don't lift them, its called a Tile Shaping Template, £10 from B&Q.

[Scott]

Or a bendy ruler. One of the guys suggested a length of plumbing solder as this is easily bent round

[Rob01]

yeah ive seen those ive got a reel of solder so ill try that out