Pretty much what rive gauche said. The holes in the back are for securing the sink to the wall to stop it falling over. They are not designed to support the sink. That's the pedestal's job.
I fitted a toilet which was about an inch too low to line up with the outlet which went through a wall. I found an off cut of plywood, placed the toilet on it, drew round the shape and then jig sawed the packing to size. A lick of white gloss and the job was a good 'un.
Pretty much what rive gauche said. The holes in the back are for securing the sink to the wall to stop it falling over. They are not designed to support the sink. That's the pedestal's job.
I fitted a toilet which was about an inch too low to line up with the outlet which went through a wall. I found an off cut of plywood, placed the toilet on it, drew round the shape and then jig sawed the packing to size. A lick of white gloss and the job was a good 'un.