Foundations for a raised floor (sub-floor?)

[RobRazzleDazzle]

Hi to all forum folk! I'll cut to the chase...

I'm renovating a bathroom. I want to build a wooden frame structure for a raised floor due to the height of the main sewage pipe and wanting to build a shower tray etc.

Currently the floor has been dismantled down to old tiles, two different areas of tiling (with about a cm difference in height between them) make up the entire space.

1) Can I build the wooden sub-floor frame straight onto the old tiled floor?

2) If yes, how do I solve the problem of the cm difference? Shims? Made out of what?

3) Should I just remove all the floor tiles and put down self-leveling thin set mortar for the foundation?

4) Or is it better to just grind down the tiles and then add a primer and then thinset to level the floor?

Please check out the pics for more details, (one pic just demonstrates the kind of wooden frame i want to build)

Thanks so much in advance for your time and expertise!

 

[Silentrunning]

Rob, there are any number of solutions to this dilemma. I would try the easiest and most effective way. For me that would be to pour the self leveling mortar mix right over the existing floor for the base.

 

[ibz1492]

Hi to all forum folk! I'll cut to the chase...

I'm renovating a bathroom. I want to build a wooden frame structure for a raised floor due to the height of the main sewage pipe and wanting to build a shower tray etc.

Currently the floor has been dismantled down to old tiles, two different areas of tiling (with about a cm difference in height between them) make up the entire space.

1) Can I build the wooden sub-floor frame straight onto the old tiled floor?

2) If yes, how do I solve the problem of the cm difference? Shims? Made out of what?

3) Should I just remove all the floor tiles and put down self-leveling thin set mortar for the foundation?

4) Or is it better to just grind down the tiles and then add a primer and then thinset to level the floor?

Please check out the pics for more details, (one pic just demonstrates the kind of wooden frame i want to build)

Thanks so much in advance for your time and expertise!

As another DIYer has stated, there are several options. First, will you be running plumbing under this floor? Is a raised floor going to cause room height problems? Is it a wooden subfloor under the tile? From the very little information you gave us, I would probably knock out whatever tile you can and get to a very firm base, wood or concrete. Then build the lowest rise platform, as you describe it, that will accommodate any and all plumbing. To level, use shims that you anchor securely to your wooden structure and off you go. I generally don't like concrete on bathroom floors.