self level onto self level

[bj F]

i was quoting a job earlyer for a kitchen, that has been self leveled. The floor has a good enough level to tile on too for most of the floor ,untill the far end of the room were it drops by about 20mm, creating a bitof a kick.
I am using 600mm - 300mm tiles brick bond following the room length ways .....so i wanted to make sure the floor was as flat as pos.

my question is ......is it ok to raise the floor 20mm with self level on to self level?

[grumpygrouter]

I don't see why not. Check with your prefered manufacturers data sheets for prep requirements.