1The Slab Finish — Most Critical
The slab must be perfect, completely flat and highly burnished to an extremely smooth, tight finish.
As many helicopter (power trowel) passes as needed, but don't over-work it, which causes delamination.
Cross-cut the slab (one way, then back the other) to avoid lumping and high spots.
Remove all screed marks, footprints and holes.
Burnish right to the edges to avoid chatter and unevenness from the hand trowel, done poorly, it will show once polished.
2Concrete Mix & Materials
We recommend double 82, 92 or 101 mesh with a 40 MPa mix.
Tell your supplier it's for a polished finish, fresh clean water, not recycled, which causes brown discolouration.
3Pouring the Slab
Use laser levels throughout, check heights even after each metre of screeding to keep it flat.
Vibrate evenly during the pour, sinks the aggregate and brings cream to the surface, reducing exposed stone.
"Class A" finish, no more than 3 mm deviation over a 3 m straight edge.
Don't use waffle-pod slabs, waffle movement can cause imperfections.
Don't pour on a wet or cold day (it can't be finished to standard) or a very hot day (shrinkage and cracking).
4Curing & Protection
We recommend ECO Cure, once helicoptered and safe to walk on, apply two light coats. Buy direct from OzGrind.
Slab must cure a minimum 28 days. Call the office to discuss if this needs negotiating.
Ramboard / Geofabric curing blankets can cause uneven curing colour. If used, ensure no crinkles or gaps, we only grind off ~1 mm for nil exposure, so any discolouration remains.
Optional impact protection: cover with corflute, but lay a breathable product (Geofabric) underneath with Eco Cure, and tape the corflute to itself with no gaps. If using plywood, ensure it won't leach tannins.
After we finish, protect with a breathable cover like Ramboard and install per manufacturer specs. See our Care Instructions.
!Even with every step followed, there is no guarantee of zero stone exposure. Choosing this finish means accepting that a small amount of pebble, aggregate or sand may be exposed in some areas, and that any imperfections in the slab will be visible after polishing.
!Any staining present before polishing will not be removed by a nil stone exposure finish.
!All methods must be done correctly for the best possible outcome. If you're unsure, call our friendly office staff.
We're excited to give you the finish you want, please pass this on to your concreter. Helping them, to help us, to help you.
