ᐅ Partition wall for a heavy washbasin

Hello everyone,

I have a question regarding the proper construction of a drywall partition with a stud frame to support a double washbasin and vanity cabinet weighing about 80kg (approx. 176 lbs) (undermount basin, 160cm (63 inches) wide, projection 55cm (22 inches)).

The plumbing company installed new piping in front of an existing 11.5cm (4.5 inches) thick perforated brick wall (approximately 4 x 2.5m (13 x 8 feet)). I now want to build a full-height drywall partition in front of that, to which the washbasin will later be mounted.

How should the wall be constructed to ensure that nothing falls off later? I have heard and found several suggestions online, but they vary widely:
1) A standard double-layer moisture-resistant gypsum board wall, 2 x 12.5mm (0.5 inch), fixed with hollow wall anchors
2) At least 22mm (0.87 inch) OSB board with a single 12.5mm (0.5 inch) gypsum board over it, then screws directly into the wood without anchors
3) A support beam only in the area where the cabinet will be hung (wood or metal)
4) A Geberit pre-wall installation frame (not entirely clear which one). The ones I have seen seem to be integrated into the drywall partition and additionally fixed to the brick wall with hooks or long connectors to transfer the load

There will also be a 160cm (63 inches) mirror cabinet above, but this seems less of an issue due to the smaller projection.

I would appreciate your tips or recommendations very much – thank you in advance!

In my opinion, no matter how you build the wall (option 1 to 4), your 80kg (176 lbs) washbasin will be securely supported by any solution. Personally, I would prefer option 2. It is simple, affordable, quick, and provides a reliable hold...

Hello seat88,

thank you very much for your quick reply. It’s great to hear that – would you use OSB for the entire wall in option 2, or only in the area around the washbasin?

I forgot to mention that I would use 50mm (2 inches) studs – or does that not make much difference?

Would you also insulate the wall with 5cm (2 inches) of mineral wool or glass wool?

I have no knowledge about insulation; I would just screw an OSB board onto the wall and install drywall in front of it. That should be fine.
I guess the type of stud profile doesn’t really matter.

I also think that all options should be stable, although I would tend to favor option 2 or option 3. Option 4 is the absolutely safest choice. Instead of OSB, you could also use double layers of gypsum fiberboard. With OSB, you would need to make sure the thickness is correct if you are not fully covering the wall.

Also, check what kind of mounting options the washbasin has! Otherwise, I would use threaded rods that go into the wall or appropriate toggle anchors that expand behind the drywall, gypsum fiberboard, or OSB panel.

We used option 2. However, the OSB panel was slightly undersized. In general, it is sufficient to generously support the suspension area with OSB.