Denser regulation of the upper floor if there is going to be tile??

[DVE]

Heard from a carpenter colleague that if you're going to have tiles on the upper floor, for example, if there's going to be a bathroom, you should space the joists at c c 300 instead of cc 600? This is to prevent cracking of the tile grout. I had never heard that before. I thought it was enough with floorboards + gypsum?

What do you others say?

The story goes that I've just framed my upper floor with c c 600 (dim 220) and I'm going to have a bathroom upstairs...

DVE

 

[bmx]

I cross-braced the upper floor to make it sturdier. I can recommend it instead of spacing the studs closer. It becomes incredibly sturdy. Truss constructions can carry much more load than a straight plank.

 

[jon_h]

It works well with c/c 600 if you apply at least 12 mm of self-leveling compound on a 22 mm chipboard. The spacing is not for the load-bearing capacity of the joists themselves, but so that the sheet material on top can support itself freely between the joists. Cross-bracing, therefore, has no impact from this perspective, provided the joist system itself is correctly dimensioned.

I recommend the pinned thread at the top of the bathroom forum for more details on the issue.

 

[DVE]

Due.. Jon_H... don't you need any floor gypsum then?

You wrote floor chipboard 22a + self-leveling compound 12mm? No gypsum? I thought both were needed so to speak...

Thanks for the tip about the "thread".

DVE

 

[Mikael_L]

The self-leveling compound replaces the plaster in such a construction, the total bending stiffness remains the same (at least).

But, I was thinking of throwing in a question, does the span of the joists matter?

I recall that below a certain span, there are slightly different requirements than above this span...

 

[DVE]

Probably found the answer myself.

If you use fiber-reinforced leveling compound, or reinforce the compound with reinforcement mesh, you can apply it directly on the particleboard.

Or?

DVE

 

[jon_h]

Reinforcement mesh is only needed in bathrooms, at least with most suppliers.

 

[Styx]

If I remember correctly, it is possible to fully glue a floor gypsum on top of the chipboard with cc60 instead of using self-leveling compound.

 

[DVE]

Glued gypsum instead of a 15mm thinset with reinforcement??

It seems like gypsum is a significantly cheaper alternative then.
Does anyone have any opinions? Can you go with that solution on cc 60 joists? Floor chipboard + Glued gypsum. Then there will be a little thinset on top anyway for the slope...

DVE

 

[hempularen]

Well, it's not that much cheaper. The gypsum board should be glued with "special" adhesive. For example, Ardex costs almost as much per sqm as 15 mm floor leveling compound.

 

[Styx]

Njaa it doesn't become much cheaper. The gypsum board must be glued with "special" glue. E.g. Ardex costs per sqm almost as much as 15 mm self-leveling compound

Completely true.
But it goes faster to glue/gypsum (if time is worth any money)

 

[DVE]

Time is always money!
Let's see what I come up with. Good to know though that you didn't completely mess up when you regelated c c 60! :- )

DVE

 

[jon_h]

If you're going to have underfloor heating, you still have to apply the leveling compound as thick as if you were applying it directly to the wood chipboard. In that case, using gypsum adhesive is completely wasted. The cost for 13 mm leveling compound will be approximately 150-170 kronor/m2, and I don't think you'll get below that if you attach 13 mm gypsum board first. And since you have to apply leveling compound on top anyway, it feels like an unnecessary step to attach gypsum board.

 

[jon_h]

Wait a minute now, I was wrong. You still need to apply 12/15 mm leveling compound on top of the floor gypsum if it's a wood joist, so using gypsum adhesive is completely wasted. You lose time, money, and ceiling height, and don't gain a thing.

 

[ktm250]

Nah... he doesn't need to then. Then he has the bending stiffness and form stability and can then apply thinner spackle.