Good substrate for tiles?

[Sir Duke]

Hello everyone

I'm planning to lay tiles in a future hallway. Right now, it's a bedroom with a wooden floor. The current floor joists are spaced at 60 cm, with the wooden floor on top. I plan to tear out the floor and add extra joists to reduce the spacing to 30 cm, and then lay floor gypsum on top.

* What dimension do you think the extra joists should be to make it sturdy and free of sway?

* Do you think 2 layers of 13 mm floor gypsum will be sturdy enough? There are ready-made 30 mm options, but they're so expensive and would create a big level difference with the adjacent wooden floor.

Thanks in advance!

 

[Stefan N]

Were you planning to lay the floor gypsum directly on the joists? For floor chipboard, I would have used self-leveling compound instead of gypsum.

 

[Sir Duke]

Hmm yeah, I was thinking of drywall directly on the joists. Seems simplest? Just glue and lay out (and screw too?)

Chipboard and filler, does it become as sturdy? There are movements in the tile layer that are a major no-no...

And self-leveling compound seems difficult. Or? I'm just averagely handy, so drywall feels nicer for that reason...

 

[Stefan N]

Chipboard and floating is indeed the most common method and is guaranteed to be stable. Floor gypsum on joists, I don't believe in for a second, unfortunately.

 

[Sir Duke]

Okay, when do you use floor gypsum then? On top of wooden floors? But why?

If I'm using chipboard and leveling compound, should I still space the joists at 30cm centers?

And how thick does the leveling compound need to be?

By the way, can you lay electric underfloor heating on the chipboard and then embed it in leveling compound?

I'm looking for a floor as thin as possible but still durable...

 

[Stefan N]

Okay, when do you use floor gypsum then? On top of wooden floors? But why? Yes, instead of self-leveling compound.

If I use floor board and filler, should I still space the joists at 30cm apart? Yes, stability is important.

And how thick does the filler need to be? Approximately 15 mm fiber-reinforced. I usually add a rot-net for extra strength.

By the way, can you lay electric underfloor heating on the chipboard and then embed it in filler? Yes, that's how it's usually done.

I'm looking for as thin a floor as possible but still durable...[/QUOTE] What you can do is lower the floor chipboard so it is flush with the floor joists and then level.

 

[Sir Duke]

Thank you for all the input!

Is 22mm particle board required?

How do you lower the particle board? Does it involve a lot of sawing to fit the boards? How do you anchor it to the joists?

Do you need cc30, i.e., add extra studs as well?