wall mount sink brackets

[Stephen Tashiro]

The directions for attaching wall mount sinks (e.g. https://www.americanstandard-us.com/...9004.pdf?la=en ) show that the bracket that holds the sink is attached over the drywall by lag screws that go into wooden bracing in the wall. It seems to me that the drywall is the weak link in this arrangement. It could get crushed and dented by forces on the sink. Do people ever put a section of wood or some stronger material under the bracket instead of just mounting the bracket on the drywall?

[Bruce Page]

That’s exactly what I did for my lumber rack. I used 1x4’s between the sheetrock and the metal brackets. There is no deformation of the sheetrock.

[Stephen Tashiro]

For a sink, the back of the sink needs to be flush with the wall. So this would involve replacing the drywall behind the bracket with a stronger material instead of putting some additional material over the drywall.

The recommended material behind a sink is "water resistant drywall" like Durock. Perhaps it resists crushing or denting as well as wood or plywood ?

[Bruce Page]

Sorry, misunderstood the question.
Do you have the 2x8 support installed as in Figure 1.? Figure 5 shows the bracket mounted over the drywall.

[Sam Murdoch]

I would not hesitate to set in a piece of 1/2 plywood (equal the thickness of the drywall). Prime it if you are worried about moisture but I would not be concerned
behind the sink. Of course your sink profile will need to cover the entire assembly so the plywood need not be much bigger than the mounting flange as long as there are studs supporting it all.

[Mike Cutler]

The directions for attaching wall mount sinks (e.g. https://www.americanstandard-us.com/...9004.pdf?la=en ) show that the bracket that holds the sink is attached over the drywall by lag screws that go into wooden bracing in the wall. It seems to me that the drywall is the weak link in this arrangement. It could get crushed and dented by forces on the sink. Do people ever put a section of wood or some stronger material under the bracket instead of just mounting the bracket on the drywall?

Stephen

I installed a large American Standard ,wall mount, sink over 20 years ago.
I removed the drywall behind the sink, sistered 2x4's to the existing studs and then placed a horizontal 2x10 across the span. where all of the mounting lag screws were going to go. I covered the wall Durock and then tiled it. This sink is as tight to the wall today as it was the first day i installed
I have no doubt that it would have mounted just fine to drywall, only because I put that 2x10 in the wall, and in order to crush the drywall, on top of that 2x10, you'd have to do something dramatic.
I do understand your hesitation though, and I would have probably pt something other than drywall under the area of the wall where contact was being made, if I hadn't put the 2x10 in the wall behind it.
In my opinion, those instruction are the minimum. I highly recommend reinforcing the entire area of the wall behind that sink.

[Wayne Lomman]

Before you sheet the wall, make sure you have extra timber in the framework to cover the load area. Do this for anywhere you want to fix something securely including WC and vanities like this. If you use the water resistant plasterboard, it is plenty resistant to crushing. I would hesitate to recommend any ply or whatever patched in. It creates potential problems with waterproofing. The less seams the better. Cheers

[Rich Engelhardt]

You're not going to crush or dent the drywall.
That's just not going to happen.

1/2" - regular drywall - has a compressive strength of right around 350/450 psi. .
Waterproof 1/2" is probably the same.

Cement (Durock) 1/2" compressive strength is around 1250 psi