Concrete thinking

The visual warmth of a spectacular sunburst and slender crescent moon emanates from the entryway floor in Bonnie Wyatt’s home in Seattle.

The design is carved into a rock-hard canvas awash in golden browns and amber hues. Yet the material of the flooring is as much a stunner as the design.

“People who come to the door go, ‘Oh, I love that,’ ” Wyatt says of the design work by concrete artisan Douglas Palmer of Fox Island, Wash. “They’re surprised it’s concrete.”

Concrete is becoming far more than the stuff of building foundations and driveways these days. The battleship-gray surface can be ground down, shined and stained to achieve a lustrous finish akin to polished stone.

For years, it’s appeared in swanky Las Vegas casinos, restaurants, auto showrooms and other commercial venues.

Now homeowners are ripping up carpet to have the concrete slab hiding below polished or stained. Some are building houses from the get-go with polished concrete embedded with radiant heating systems.

“Concrete polishing is an ever-expanding part of our business,” says Dale Hoyt, whose floor installation and maintenance company in Puyallup, Wash., added concrete polishing to its services two years ago.

Though the bulk of the decorative concrete work is commercial, residential jobs are growing for the Diamond Polishing Systems division.

Hoyt says people are discovering “it’s a very green floor, a very natural and pretty floor.”

Douglas Palmer’s ConcreteScape on Fox Island has specialized for more than seven years in decorative concrete for residences.

Besides staining and polishing, Palmer stamps textures in freshly poured concrete and, in cured concrete, can score designs or etch lines and fill them with grout for a tile-like look.

“We do acid stains to bring character to the floor,” he says. “You can ‘marble-ize’ it. You can do checker patterns, with some sections that are lighter or darker. You can do mosaics. We feel like it’s a piece of artwork.”

Beyond aesthetic preferences, decorative concrete offers practical advantages over other types of flooring, owners and contractors say:

•It’s more durable than hardwood, vinyl or carpet, especially for leaky basements in the rain-soaked Northwest. If properly installed and finished, concrete never needs to be replaced.

•It’s environmentally friendly. Making slab foundations do double duty as flooring allows homeowners to skip buying glue, wood or other materials to cover the concrete; that saves resources, according to “Ed Begley Jr.’s Guide to Sustainable Living” (Clarkson Potter, 2009).

Plus, concrete’s main ingredient, limestone, is so abundant people needn’t worry about using a disappearing resource. Consumers can look for concrete mixes with a high rate of recycled materials such as fly ash, a by-product of coal-burning plants, actor and environmentalist Begley writes.

•It’s a healthy option for allergy sufferers. Wall-to-wall carpet can harbor dust mites, grime and mold, and emit harmful gases called volatile organic compounds. Dirt, pet dander and the like can be easily removed from concrete floors through damp mopping with water or a neutral pH cleaner.

Yet it’s not for everyone.

The Concrete Network, which describes itself as the “independent voice of concrete,” concedes decorative concrete floors can be hard, loud to walk on and cold without radiant heating systems.

Area rugs can address those concerns. Moisture vapor seeping through the concrete can be a more intractable problem, if the slab wasn’t correctly insulated or was built atop a poorly drained area.

And cost can be a downside for some homeowners. The initial investment can be higher than low- to mid-priced flooring, such as carpeting, vinyl tile or wood laminates, the Concrete Network says.

But, the network adds, concrete artisans can achieve the look of higher-end ceramic tile, slate and marble, making the long-lasting floors an economical alternative.

Hoyt, whose umbrella business Premier Floors and Design Center installs hardwood, laminates and carpet, says the base price of polishing, without staining, runs about $4 a square foot, about the same as a moderately priced carpet, pad and installation.

But as with any home improvement job, costs differ based on individual situations. Removing a tile floor and the underlying glue, for instance, costs more than just polishing an open slab.

Clint Harris weighed the options and decided on polished concrete for the main floor of the 3,500-square-foot home he’s having built in Monroe, Wash.

Before pouring the concrete slab, a contractor laid down hot-water tubes for radiant heating and added color to the concrete mix. After the substance cured, Hoyt’s company polished it.

“We did this because it’s easy to clean, and nonallergenic. We have kids who are sensitive to allergies,” says Harris, a father of five.

He’s pleased with the result: a mirror-smooth finish of white and black pebbles against a soft-chocolate brown background.

“It’s very pretty. It’s surprising,” Harris says. “It doesn’t look like concrete. It’s speckled. It looks more like granite.”

Though contractors use an assortment of techniques and chemicals, polishing concrete generally involves using heavy-duty polishing machines to grind down a rough concrete surface multiple times using a series of diamond-embedded metal disks with progressively finer grits, Hoyt explains.

Once the surface is smooth, diamond-embedded resin disks with ever-finer grits are used to polish the floor to a high sheen. The final look varies greatly, depending on stains and designs, and the natural variability of the concrete itself.

The deeper workers grind, the greater the chance of getting down to the pebbles that make the flooring look like a sheet of sliced stones. And the finer the grit used for polishing, the greater the luster.

Wyatt is elated with the radiant-heated entryway that she added to her home. Palmer carved the sunburst design that Wyatt provided, added stain and polished the concrete flooring.

Now she’s planning an addition to the post-war rambler house.

“I wanted something really special and that’s what we came up with,” she says of the entryway.

“We’ll definitely do the heated, poured concrete floor again. They’re so easy to care for. I love having a warm place to go barefoot.”