Replacing chipboard floor for tiling advise

[tony Dimartino]

Im about to rip up a chipboard floor which is falling apart, I was going to lay ply and overboard with NMP or Hardie, Ive seen that there is 22mm backing board can this be used directly on to joists or does am i better laying ply and then a 6mm backing board? Any adivise appreciated

also one of my stud walls needs reboarding and is part of a shower, should i use 12mm NMP straight on to the metal studs and does this need tanking?

many Thanks

 

[Boggs]

I would replace the floor with new chipboard, then overlay with 6mm Hardie Backer stuck to the chipboard and screwed at 150mm centres.
The 150mm is my preference.

When removing complete floors just be mindfull of the wall that goes the same way as the joists, if there is not a joist underneath the wall make sure you only take back the existing floor to the nearest joist in the room, otherwise the wall will have nothing holding it up and may start to drop over time.

I would not bother with Hardie Backer on the walls, use 12.5mm moisture resistant plasterboard and tank or buy Wedi or Delta etc boards.

 

[Old Mod]

Ive seen that there is 22mm backing board can this be used directly on to joists

22mm NMP or another product called GIFA board can both be fitted direct to joist and are structural materials.
Where possible I’d always substitute any type of timber or particle board flooring for these products.
They’re inert materials and are unaffected by moisture and temperature change.
And also keep build up to a minimum.
But that’s my personal preference.

And as above, wedi style sboards on walls.
Although personally I find metal suds can be a little flimsy depending on the stud centres.
I’d be concerned that a single skin 12.5 wedi board straight to metal stud would not be stable enough.
Personally I like metal studwork to be double skinned.
As long as the outer skin is waterproofed/tanked correctly, the inner board could be pretty much whatever you want.
It’s the double layer that provides the strength.

Not disagreeing with Boggs at all, I’d just take a different approach maybe, depending on circumstances.

 

[Waluigi]

Over in Germany that’s exactly how they deal with metal stud work. They double board it.

Regarding the floor, I would use a decent quality ply wood (18mm) exterior grade. Wickes sell it. And then glue and screw HB onto this. Then tape the joints.

 

[Boggs]

Oops, might have confused him now!

 

[tony Dimartino]

22mm NMP or another product called GIFA board can both be fitted direct to joist and are structural materials.
Where possible I’d always substitute any type of timber or particle board flooring for these products.
They’re inert materials and are unaffected by moisture and temperature change.
And also keep build up to a minimum.
But that’s my personal preference.

And as above, wedi style sboards on walls.
Although personally I find metal suds can be a little flimsy depending on the stud centres.
I’d be concerned that a single skin 12.5 wedi board straight to metal stud would not be stable enough.
Personally I like metal studwork to be double skinned.
As long as the outer skin is waterproofed/tanked correctly, the inner board could be pretty much whatever you want.
It’s the double layer that provides the strength.

Not disagreeing with Boggs at all, I’d just take a different approach maybe, depending on circumstances.

Thanks for your reply, one of the walls the plasterboard is completly off, would i be better adding more noggins? or using a 20mm marmox board instead?

 

[Old Mod]

Depends on it’s construction really. You just want it to be solid and deflection free.
If you can push boards in, it needs more support. The more solid it is, the more suitable it is for Tiling.
If there’s too much movement in the structure. It will fail.

 

[Waluigi]

which tiles are you using for your walls? Size and material.

 

[tony Dimartino]

which tiles are you using for your walls? Size and material.

Hi im going to be using 600x300mm 9mm porcelain tiles, on the wall, Im really confused on the best way to go. Have a look at the pics this is were the shower is going, do u think no more ply 12mm boards would be stronger than using 20mm marmox?

 

[Boggs]

The walls will definitely need some more uprights.
From experience I can say 12mm Hardi on metal stud work won’t go anywhere in a hurry!
But the walls I worked on were 450 centres if I recall.