new floor

[petedenno]

The wife walked in with floor tiles for the bathroom,after inspection ,the blockboard has gone under the bath and has lifted in several places,so what do I replace it with and what thickness I am toying with u/f heating havent made my mind up yet ,will it be the same hope you can help cheers ... petedenno

[dock]

Hi

Replace floor with minimum 18mm exterior grade ply. Insert noggins in between the joists to enable the ply to be screw fixed at MAXIMUM 300mm centres (200mm better).

Fix down Under Tile Heating, commission and prime with Mapei ECO Prim T. When dry "blind" the UTH with Mapei Fibreplan.

Fix tiles in Mapei Keraquick.....note no additive required. Ensure there is a solid bed of adhesive under the tiles.
Grout with Mapei Ultracolor Plus (26 colours)
Fill movement joints with Mapei Mapesil AC (27 colours)

hope all goes well

dock

[petedenno]

thanks dock looks like Ive a busy weekend cheers petedenno

[Fekin]

As you might have guessed, Dock likes Mapie

For the boarding out of the floor, personally I would use backerboards as these are far thiner than 18mm ply so the floor isn't going to be raised as much and also they do not swell and bloat up and bend if water gets to them like Ply would.

[dock]

Thanks Fekin lol..................hope thee thumbs gettin' better!!!!

dock

[Fekin]

Aching like a *@#*!r I can tell ya

[grumpygrouter]

Think Dock was saying REPLACE the chipboard with ply not overboard Feks. Height isn't an issue at all then.