Concrete garage floor over tarmac base?

[millfield]

Hi

I have a garage floor 2.6m x 7m which is actually the tarmac driveway - it has been in place about 25 years or so and is stable and solid.

Can I lay concrete on top of the tarmac (with a damp proof membrane on top of the tarmac) or must I dig up the tarmac base and have a hardcore base?

If I can lay concrete on top of the tarmac is it likely to have any effect of the footings of my house (the garage is adjoining the house to its side).

Thank you.

Rob

 

[noseall]

You must remove the tarmac prior to laying the conc.