Mix and Matchby Kelly O’Brien
Specialized Concrete Artisans Inc., Waterloo, Wis.
This versatile staining technique creates a rich mottled finish that can be used on either newly poured, ultra-lightweight concrete or preexisting standard-weight slabs — or on a project that includes both.
Lycon Inc. ready-mix concrete, with Nova Chemicals Elemix additive mixed in at 40 gallons of Elemix per cubic yard of concrete (the finished slab weighed in at 100 pounds per cubic foot)
Rapid Set Skim Coat
Butterfield Color Elements water-based stain: Cordovan Leather and Brown
Surface 519 Rockshield Primer - Step 1
Surface 519 Rockshield - Step 2
Surface 519 Rock Renew
Special equipment required: McTech Group UltraCure NCF wet-curing blankets, McTech Group EZcover Protective Covering, Innovatech Predator P-2400 grinder with 50- and 100-grit resin-bond diamonds plus buffing pads, SP Systems pump sprayers
- Prep the substrate prior to placing your lightweight slab. In this case, the slab was going down on a wooden deck covered with 1-inch rigid insulation and radiant heat tubes, over which the contractor installed rubber expansion material and a heavy-gauge wire mesh.
- Once your substrate is prepped, place the lightweight mix and let rest overnight.
- The next day place your control joints, then flood the floor and cover it with curing blankets, laying them out as wrinkle-free as possible.
- Let cure for a week, and then remove the curing blankets. Scrub the floor clean and allow it to dry for several hours. Then cover the entire surface with the EZcover so it can be walked on safely while it finishes curing. The curing process should take 21 more days, assuming 28 total days required to cure.
- If you are staining an existing slab as well as the lightweight slab, you’ll want to prep the surface and remove any trowel marks by running a grinder with 100-grit diamonds over the old floor to smooth it out.
- Once the lightweight slab has finished curing, you’ll grind that as well to prepare it for the stain. For a cement-rich mix like the one used here, use 50-grit abrasives.
- Mask off any surfaces adjoining the areas to be stained, and wash the floors thoroughly.
- On the lightweight floor, start by spraying a mist of acetone across the surface. This will melt any exposed beads from the Elemix additive.
- Mix up a small batch of Skim Coat and trowel it tightly over the floor to fill the small voids left from the Elemix. You may need to use several batches for full coverage.
- Let the Skim Coat set for several hours and then use a buffing pad to remove excess residue from it. Wash off the slab and it’s ready to go.
- From this point on, the instructions are identical for the lightweight and the preexisting slabs.
- Mix each color of the Elements stain with water at the standard dosage and pour through a strainer into an SP sprayer fitted with a green No. 4 tip, which will give you a very fine mist.
- Apply the Cordovan Leather first in a very random and sporadic pattern, going from fairly heavy in some areas to almost nothing in others.
- Once the Cordovan Leather stain is dry enough to walk on, apply a second treatment of Brown, filling in the lighter areas and lightly misting over the dark ones.
- Use Q-tips to apply color flush against the walls.
- Let the stains dry completely.
- Mix a batch of the Rockshield Primer - Step 1 and strain into an SP sprayer fitted with either a red No. 6 (fine mist) or gray No. 8 (regular mist) tip. Spray an even coat over the entire surface and let dry.
- Repeat procedure with the Rockshield - Step 2, and let dry overnight.
- The following morning apply Rock Renew to the surface to provide a final, sacrificial wearing surface that will be fairly simple to maintain.