Vanity unit hung on internal wall

[tracyon]

I’m redoing my bathroom and would like to move the position of the sink which is currently on an external wall to having a wall hung vanity on the opposite internal wall. Previous workmen have commented how bad these walls are..described as honeycomb.
Can I arrange some kind of support to hold a wall hung unit? I would really prefer the clear floor space.

put legs on it and stand it on the floor.

Or, you can attach a sheet of 18mm ply to the wall, of the exact with of the vanity unit, using a large number of cavity fixings, and fix the unit to that. Paint it to match the wall, and it will be (mostly) hidden by the unit. It should start at skirting level and go as high as you can possibly manage. Most of the weight leverage will be trying to pull the top edge away from the wall.

If you make the board taller and hide it with a large mirror that will improve the strength.

I suspect your wall does not have any wooden studs and is mostly made of air.

Thanks very much!

I’m going to be doing this in my remodel. I will be putting a frame in the wall to support the sink and unit.