While hand-mudding vertical concrete projects is the preferred method for getting a working surface ready to be shaped and carved, for bigger jobs it’s not necessarily efficient.
Enter a spray system — often known as shotcrete — which has been around for more than 100 years. The idea is that with the right mud mix and the right pump it’s possible to cover larger work areas quickly and evenly.
Emil Gera of Gera Concrete in Weatherly, Pennsylvania, says for the right job, say a 40-by-10-foot wall, he certainly considers shotcrete to get the best coverage.
“If we’re going to be doing a really large project,” he says, “I’ll order a blend from the local concrete company and spray it.” Hand-mixing for that amount of coverage would be overly time consuming.
Danny Carrillo, development manager for Minneapolis-based Graco’s ToughTek line of pumps, says if it’s something a concrete contractor needs, ToughTek will shoot mortar onto floors, walls or ceilings, regardless of the underlying substrate.
“Depending on the material, the application can go anywhere from a half-inch to two inches in thickness,” he says.
And, while Carrillo says he won’t recommend a particular product, at one time or another the company has probably experimented with it — including most of the admix concrete-carving products.
The only difference: many require either a lime or clay product to aid in pumpability.
“We know the proper mixes for the materials that will pump under any circumstance,” he says. “They can adjust from there.”
However, he notes that anything with an aggregate size greater than a quarter-inch probably won’t work. Clean sand is a must, as well.
Still ToughTek operators regularly use pumps to apply anything from stucco and fireproofing products to self-leveling flooring. Normal capacity is one-to-three pallets per hour.
Carrillo says the other advantage to ToughTek pumps is that they’re available in different sizes — but none is too large not to fit in the back of a small pickup or through a standard door. Both 110-volt and 220-volt three-phase models are available.
