Concrete on slabs

[swampydrill]

At the bottom of my garden i have a dog run and garden shed, prior to that i have a small patio area, this area is around 4 inches lower than the dog run / shed area. I am planning on buying a much longer shed which will cover the dog run area which is all concreted, due to the extra depth, it will also encroach onto the patio are by around 2ft. The slabs were originally laid on around 6" of concrete, is it ok to concrete on top of this, at its shallowest part it could only be around 3" of concrete on top of the slabs. Also will the concrete bond ok to the edge of the existing concreted area ?

 

[^woody^]

You should be OK. Dampen the slabs before concreting and brush on a cement slurry.