New bathroom floor

[gobuddygo]

I want to lay a tiled floor in my bathroom and understand that laying a thick sheet of plywood over the current T&G floor would be the normal route, but as the current floor is in such bad condition (split, missing, and creaking boards) I am considering ripping up all the current boards and replacing the whole lot with 18mm plywood using extra noggins if need.
I will be fitting a new bathroom suite as well so that wont be in the way.
Is this a good plan?
Thanks in advance - Frank.

[B17NNS]

Yes, that will be fine with the added advantage of not raising the floor.

[gobuddygo]

Cheers that was another benefit, do you think i could get away with 15mm for the same reason?

[B17NNS]

I'd be tempted to stick with the 18mm personally. The less chance of movement the better. Don't be shy with the screws and use a quailty powdered flexible adhesive and grout.

[SLacKer]

Your biggest issue is movement in the floor causing cracking of tiles and/or grout ruining your hard work.

You could use Ditra to seperate the tiles from the undefloor http://www.schluter.co.uk/produkt.aspx?doc=6-1-dit...

It has the advantage of a complete waterproof barrier as well (assuming and upstairs bathroom) and requires a floor in reasonable shape so relaying the floor sounds like a plan.

As an alternative you could use Hardiebacker board. B&Q and Topps Tiles sell it and it is 6mm high so will not build the floor up to much.

[gobuddygo]

I will go with 18mm ply, extra noggins, screwed every 5cm and flexible adhesive/grout, its only 3.5 suare metres so should be pretty easy - cheers.

[Illustrious_Lou]

SLacKer said:

Your biggest issue is movement in the floor causing cracking of tiles and/or grout ruining your hard work.

Could lay Amtico tiles instead of ceramic tiles. Small movements are not a problem, fine with water and much nicer underfoot than cold tiles.

I have it and 6 years on it still looks like new.

[mackg]

I'd still over board the 18mm ply with at least 6mm ply screwed at 6" centres making sure you overlap existing joints by 300mm to prevent any cracking