Hi guys,

tiled many floors and walls over the years at various properties of my own, friends and family, and am happy to get on my hands and knees and get filthy again, but put the feelers out for someone to come and do my latest requirement simply due to the size of the area concerned (70m2) as it's well over anything i've done before plus it's using 600 x 600 Porcelain tiles which I've never laid before and don't fancy getting it wrong due to the cost already outlaid.

The floor is in a new build extension / conservatory, 50% in the conservatory 50% in a standard construction build. 9" x 2" wooden joists with 18mm waterproof treated chipboard surface.

I've tiled onto chipboard before with no issues using flexi adhesives but I'm being advised by a couple of guys that they'll need to use Ditra and won't touch the job otherwise.

Is it really a requirement, will a flexi adhesive not do exactly the same thing and allow some flex and movement?

All advice and suggestions appreciated

Iain

HI and welcome... So the whole floor is one substrate...Chipboard..?..

flexi adhesives deforms and then reforms to a certain tolerance..

ditra uncouples , seperates at different points and then re aligns aleviating the stress on the tile...

hope this helps
ed

Originally Posted by Dave

HI and welcome... So the whole floor is one substrate...Chipboard..?..

Yep, 18mm chip board straight though the entire area.

Originally Posted by AstonTiling

flexi adhesives deforms and then reforms to a certain tolerance..

ditra uncouples , seperates at different points and then re aligns aleviating the stress on the tile...

hope this helps
ed

Ummmmm, pass lol

The floor just needs overboarding and an S2 quality adhesive...

How often is the floor nogged..?

Are you sure the floor is solid - with no deflection whatsoever - as ditra will only do the job if that is the case and to be honest, you are better to overboard with 6mm Hardiebacker in my opinion, then tile with a flexy adhesive like Mapei Keraquick with Latex Plus additive. Ditra will not stop the tiles cracking if there is any deflection and if there is, you need to strengthen the floor before you progress further.

will a flexi adhesive not do exactly the same thing and allow some flex and movement?


hi mate, i was just explaining the difference for you between what a flexi adhesive does and a uncoupling system..sorry if it came across a bit techy..

No worries Aston lol

Dave - The floor joists in a large part of the area are sat on top of a solid concrete slab, they were only used to raise the height. They are nogged around every 600 or so. The rest of the floor is suspended and again nogged around every 600 or so. There is no noticiable movement in the floor at any point.

Grumpy - Not sure what you mean by deflection, sorry?

it's gonna turn into a very expensive job 6mm backer boarding 70square meters pal, i agree probably the best stuff to use but you'll be looking to add a £1000 on the job useing it ! id use 12mm ply throughout with flexy add and grout

Originally Posted by caliperkid

it's gonna turn into a very expensive job 6mm backer boarding 70square meters pal, i agree probably the best stuff to use but you'll be looking to add a £1000 on the job useing it ! id use 12mm ply throughout with flexy add and grout

agreed, but Ditra is a must for job like that, 12 mm ply on top, and then Ditra mating all the way, would stick Ditra with mapei adesilex VS45 glue, use 1.6 v-notched trowel to stick it
good luck

Cross bond it with 10/12mm ply screwed at 200 centres will give you the strength then as the man above says with VS45 to counter your latteral movement.

Wasting time and money with cement board..........






..

So if the floor is solid and no deflection why cant he tile directly onto the chipboard with the correct flexi addy, the only problem i can see is that some waterproof chipboards have a waxy finish to them which can cause delamination though ive never come across this myself.
Lucius

Originally Posted by lucius

So if the floor is solid and no deflection why cant he tile directly onto the chipboard with the correct flexi addy, the only problem i can see is that some waterproof chipboards have a waxy finish to them which can cause delamination though ive never come across this myself.
Lucius

You just answered your own question Lucius.

Chipboard/waxy finish/delamination. Not good ingredients for any floor.