Part tile part plaster…

[G and J]

Our new build will have three bathrooms, each with a mixture of fully tiled walls, plastered walls, and part tiled part plastered walls.

 

The very highly recommended chap doing our plastering has advised us not to try plaster on tile backer boards.  
 

So how do we do the part and part walls.   We are using some big tiles (1200mm x 600mm) so plasterboard, we are reliably informed, isn’t strong enough.  So do we have a split wall - plasterboard on the top half and tile backer on the bottom?  If so is the join best placed under the top edge of the tiles?  How do we ensure that the levels work?

 

Any other suggestions?  We can’t be the first people to do this!

[Russell griffiths]

The cement faced foam core boards can be skimmed, but you use a specific primer. 
definitely not pva. 

[Nickfromwales]

2 hours ago, G and J said:

so plasterboard, we are reliably informed, isn’t strong enough

Hmmmmmmm.

 

So, here's the facts  

 

Stud walls for bathrooms should be at 400mm cc, not 600mm. The weight per m2 is the concern, but if your tiles are that big then......so what? It's still exactly the same kg/m2 as you putting 100x100mm tiles on. If the tiles you bought are 30kg/m2, then so will tiles 25mm x 25mm be. It's physics.

 

Where you apply the math is the board and the way its fixed, so you'd be going for 12.5mm MR PB (if I was doing it) and then screwing it to studs at 400mm cc, and having a screw into the PB at every 100mm max cc. Then you could patio slab the damn walls. If you have studs at 600mm cc then you (or I) would then be installing horizontal noggins to create 400mm cc horizontally. This would give you boxes of 600mm x 400mm which you'd then divide the installed weight of your BFO tiles, per that exact amount of area.

 

You've not been reliably informed.

 

I've been sticking BFO tiles to bathroom walls for 3 decades, and not one's fallen off....yet. I've always used plasterboard, and always gone bat-shit crazy on studs and screwing the MR PB to them. Then I tank the shit out of everything, to the point people think I need help, and the results speak for themselves.

 

No need for fancy XPS boards, cement or tile backer boards, all just stuff introduced so it can be sold to folk to turn a profit.

 

"No".

 

 

[saveasteading]

9 hours ago, Nickfromwales said:

Stud walls for bathrooms should be at 400mm

I haven't heard that before. And either it has 'just been done' and I haven't noticed or it seems cautious, as I have no recollection of any issues  (a few family projects and accommodation, but lots of commercial, sport and education).

 

Is it to stop deflection ( and tile cracking)  from accidental shouldering, or for supporting appliances* ( in which case noggins around 600 up i agree would be prudent).

* do people stand or sit in basins?

 

But changing 600 to 400 for the smallest rooms is easy so I'd like to understand the perceived concern.

 

 

[Nickfromwales]

1 hour ago, saveasteading said:

I haven't heard that before. And either it has 'just been done' and I haven't noticed or it seems cautious, as I have no recollection of any issues  (a few family projects and accommodation, but lots of commercial, sport and education).

 

Is it to stop deflection ( and tile cracking)  from accidental shouldering, or for supporting appliances* ( in which case noggins around 600 up i agree would be prudent).

* do people stand or sit in basins?

 

But changing 600 to 400 for the smallest rooms is easy so I'd like to understand the perceived concern.

 

 

Random grab. Build for the situation, plan for the build, do it right once.

 

 

Do Stud Walls Have 400 or 600 Centres in the UK?

In the UK, the spacing between studs in a stud wall is typically 400 millimetres on centre, which is referred to as "400 centres." This spacing is in line with the building regulations and standards in the UK, which specify the minimum spacing requirements for timber studs in walls.

However, it's worth noting that the spacing may vary depending on the specific construction project, as the requirements may differ based on the load-bearing capacity and the types of materials used in the wall construction. It's always best to consult with a professional builder or structural engineer for specific information on stud wall spacing for a particular project.

[Nickfromwales]

1 hour ago, saveasteading said:

Is it to stop deflection ( and tile cracking)  from accidental shouldering, or for supporting appliances* ( in which case noggins around 600 up i agree would be prudent).

* do people stand or sit in basins?

It's to take the known (or anticipated) weight of the tiles, as it's going to be bathroom I spec 400mm cc or for the walls at 600mm cc to be sheathed with OSB. Usually the OSB option is favoured, as it means that anywhere you go to put a screw of fix a towel rail etc, there's something to screw into. It's also a bit better for sound deadening too.

[saveasteading]

1 hour ago, Nickfromwales said:

to take the known weight of the tiles

I'd have to ask the professionally active SEs on here if they allow for this.  I don't recall ever allowing wall tile loading, except as  adding to the weight of the wall if it bears onto any lower support, eg joists.

 

OSB I'd prefer as it will take all sorts of heavy fixings with ease.