Extending a concrete garage base

[billtomlinson22]

Hello
I am currently extending my existing concrete garage base as i have bought a larger garage.
Does anyone have any tips on the best way of tying in the old base to the new.
I am extending the rear of the base by 18 inches and as the back of the existing base is 2 feet above ground, and will take the full weight of the rear of the garage i am concerned that if i do not tie them together proprerly then over time the new may break away from the old.
Many Thanks
Alan

 

[noseall]

dig the new one under the old one, say 300mm and also thicken the load bearing edges of the new slab providing a 'toe'.

 

[Deluks]

Depending on the thickness of the old slab, you could drill into it from the side, and resin fix some rebar which will be encased in the new slab pour.