soundbloc

I'd like to use a soundproof plasterboard on this ceiling, what thickness do I need? It's just going to be a ground floor bedroom. What additional measures are necessary to make the use of a soundproof plasterboard effective?

Hi all, I'm going to stick some soundblock 12.5mm onto existing wall (which is made of square plastic compartments covered with plasterboard) I'm thinking of using green glue to stick it on, because it cuts down structural transmission of sound. but when i look at the green glue how to video...