best way to raise a belfast sink 6mm to meet quartz worktop

[needmorstuff]

I have installed a belfast sink on a unit.. the unit lines up with existing units. trouble is the belfast is about 9mm lower than where the worktop is going to go.. the fitter said he could fill the 9mm gap with silicon but i said i would raise it..

would using 6mm plastic shims all way around base of belfast work? and should i then silicon all way around the belfast to hold it secure?

or is there a better way?

 

[Ian2008]

Sit the sink on a piece of 9mm plywood cut to match the sink footprint.

 

[needmorstuff]

the top of the sink is irregular.. if i put it on 9mm ply it would hit the quartz.. plus now i have the door on ans the facia panel its not going to be 6mm more like 4 or 5mm.

 

[needmorstuff]

i see there is 5.5mm external grade plywood to be had. is that a better option than using plastic shims then? i could do with some anyway to box something in.

 

[needmorstuff]

its all plumbed in now so i'll cut 4 strips and insert them under each edge, same effect but less hassle. then i'll pop a bead of silicon around to hold it fast.