HardFrost

Hi guys I’m new to the forum, please be gentle with me! I have built an enclosed workshop on a tarmac driveway - the floor of the workshop is the tarmac. I believe there is a concrete slab about 30mm below the tarmac… I don’t know for sure that the slab is continuous, nor do I know the condition or thickness of the slab because the tarmac was down before we moved in. The tarmac wasn’t great to start with but now there’s trolley jacks and the ocasional spillage to contend with it is getting scrappy. Every time I sweep I’m bringing up the aggregate 😕 I should like to have a non-porous, flat, smooth, strong floor without adding more than 15mm to the existing height of the surface. Is there anything I can pour / trowel / paint onto the tarmac to seal it, stabilise the surface and level it off? Or am I stuck with excavation as my only option? The area is approx 25m2. It is bound by existing tarmac front and back, the house on one side and a dwarf wall on the other. There is no DPM under the tarmac - this is not a problem for me, but may affect the solution. We live on the top of a hill… and the subsoil is sand and ballast… we don’t have drainage problems! The workshop is a wooden structure and is built directly onto a 300mm engineering brick (and waterproof mortar) dwarf wall and leans-to against the house. Front and rear are full height / full width doors. If you need more information, please let me know. Thanks for your help.