Refitting a fallen kitchen cupboard to a plasterboard stud wall

[Roy22]

Replace a section of plasterboard with ply, put your rail on and be done with it

Even though the ply will be only 12mm thick? Earlier on I was advised to get 5 x 70mm screws, to bury deep into the stud/noggin. As a DIYer, I'm a little confused how much depth is needed?

Incidentally, I found a very interesting YouTube comparison testing of various plasterboard fixings, including one improvised one which was the second best of the lot:

The ones which failed so spectacularly in my kitchen were these, which the above destructive testing video found to be near the bottom of the performance range:

https://www.screwfix.com/p/fischer-self-drill-plasterboard-fixings-metal-35mm-100-pack/47347

 

[robinbanks]

Even though the ply will be only 12mm thick?

Yep. If you're bothered that it will only be 12mm cut another strip and glue/screw it on the back so it's now 24mm thick (don't put extra where the stud is, so it doesn't stick out any further;doesn't need to be thicker where the stud is, as the studs is notionally adding 3+ inches to the ply

So now you have at least 24mm to screw into