Class-B Aggregate Exposure: 85% Fine Aggregate, 5-15% cement fines and coarse aggregate.
Class-C Aggregate Exposure: 80-90% coarse aggregate, 10-20% blend of cement fines and fine aggregate.
Part I: Before Framing
Grinding on an Open Slab
If you want your polished concrete floor to have aggregate exposure showing the small to medium rocks, what is known as Class B or Class C, it is best done done on an open slab before framing.
See the accompanying chart, at right, for details.
Scoring on an Open Slab
The concrete on a new slab is softer and ideal for scoring.
If floor is to be scored without borders ideally that should happen before framing.
Part II: After Dried in, Before Drywall
If the walls are already framed, we can either score to a border or to the walls with a hand held tool to cut lines up to the walls. Some change in the texture of the lines should be expected in this instance.
When using foam insulation, schedule floor and covering beforehand (that stuff sticks to concrete well enough to require grinding to remove).
Finishing to Class A aggregate exposure should happen after the house is 100% dried-in, but before installing drywall.
Part III: Final Polish
Q:What is a Final Polish?
A: A final polish is the application of a final coat of stain-guard. We polish that into the floor with an 800 grit diamond-impregnated pad on a propane-powered burnisher. The final polish is not a cleaning service. We budget roughly one hour per 1000s/f to get it ready for stain-guard and polishing. This can be omitted if you like how the floors look now.
Q: When Should the Final Polish be scheduled?
A: At the end of construction, after appliance installation, plumbing and electrical trim-out, and amid the final cleaning. The floor needs to be clean and dry for that, but it makes a little bit of dust so it should be scheduled at the very end of your project but still expect your clean up crew to do a final touch up.
Q: Should the masking paper be replaced?