With my experience i will suggest you to go for waterproofing coating process.
How to waterproof concrete roof slab.
Apply the finish system you have selected to the wall according to the manufacturer s directions.
Work systematically from one end to the other spraying in lines.
Topical sealers can be made from acrylic epoxy and polyurethane based materials.
Finishing up and other considerations 1.
Pour your chosen vapor barrier into a paint sprayer after the primer is dry and liberally spray an even coat onto the concrete roof.
Overlap the previous line every time you start a new one.
Allow the vapor barrier to dry before you add a second coat.
When waterproofing concrete a topical sealer is applied to the surface of the concrete.
Deciding which walls to waterproof and which ones to forgo can save you.
You can waterproof a concrete slab roof terrace by sloping the slab gently with mortar towards the roof gutter if there is any then sloping the roof gutter towards the downpipes such that the stormwater is adequately collected.
Apply a suitable.
The sealer is impermeable provided it is applied correctly and forms a waterproof membrane around the concrete preventing moisture from entering the concrete.