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Gypsum Solutions

Equipment for pouring high-rise flooring.


June 2, 2020
By Tripp Farrell, president, Blastcrete Equipment

Topics
The trailer is an underappreciated feature of a gypsum pump, since it’s critical for getting the equipment to the right spot on a job site. Especially important for rental units, of course.

Now that construction is getting back on track across the country, rental stores and their contractor customers are looking for ways to diversify their offerings and find new revenue streams to make up for a slow spring and uncertain demand going forward.

Renting gypsum pumps for high-rise flooring applications is an intriguing possibility, and one few stores have gotten into.

Before the pandemic, multi-family residential unit completions were at record numbers and showed little evidence of slowing down into 2020. Now, everything has slowed, but there’s no reason to believe this construction sector won’t return as quickly or more quickly than any other. These projects create an ideal environment for contractors looking to break into or grow their business in high-flow material markets with gypsum floor underlayment, grouting, cellular concrete, plaster and stucco applications. However, success in this field requires an investment in specialized equipment — a limiting factor for many bottom-line-conscious contractors. Renting is the way to offset these equipment costs. Recent innovations in gypsum mixer/pumps have made these units more affordable, user-friendly and versatile than previous options. With the right equipment and customers, rental stores can see quick ROI and contractors can see increased efficiency.

Gypsum concrete – often referred to by its Maxxon brand-name, Gyp-Crete – is a popular material for flooring underlayment over wood and concrete substrates. It’s lightweight and fire-resistant and weighs less than Portland cement. It’s faster and easier to apply and level because it’s less viscous. Nails can even be driven into it without chipping. So it is not hard to see why gypsum cement is a popular material for high-rise flooring. It can be pumped up to the necessary floor and quickly spread to give the floor covering a level surface. It doesn’t produce dust on its surface the way concrete does. But the big benefit is fire protection and sound reduction.

Applications requiring radiant in-floor heating are especially strong for gypsum. Regular concrete gradually destroys the copper tubing used for radiant heat, but gypsum concrete does not.

The time is now for gypsum concrete as improvements have been made to its formulation over the last 15 years or so. Gypsum concrete used to have a reputation as being soft and chalky compared to regular concrete. That just isn’t true any more. Newer formulations can actually have a higher compressive strength than concrete, even up to 10,000 psi. It’s also a binder that can be mixed with various sands and aggregates to create application-specific surfaces. That’s where mixers and pumps come in.

Here are several key factors to consider when selecting a gypsum mixer/pump to maximize productivity and profitability.

Pump Type
The type of pump is perhaps the most important feature to consider when investing in a gypsum mixer/pump. For contractors considering lower output gypsum applications such as radiant heat, smaller and more economical peristaltic/squeeze pumps can be used successfully. However, squeeze pumps will surge, which results in a light interruption in material flow. Minimal surging can lead to splatter on drywall, resulting in unnecessary cleanup. The squeeze pump has a maximum 450 psi line pressure which limits pumping distance to around 300 feet.

Rotor-stator pumps, on the other hand, provide continuous flow, eliminating surges and increasing productivity. These pumps can generate up to 600 psi of pumping pressure — about 30 per cent more than squeeze pumps — for pumping distances in excess of 150 feet vertically and 500 feet horizontally.

Recent advancements in rotor-stator technology led to the introduction of an adjustable rotor-stator pump with inline pressure gauge to the gypsum mixer/pump market. This innovation allows contractors to adjust flow to meet a project’s unique requirements. Tightening the rotor-stator results in maximum pumping distances, which is ideal for high-rise and long-distance jobs. When the job requires shorter pumping distances — between 200 and 300 feet — contractors simply loosen the rotor-stator. This flexibility results in optimum pumping pressure for the application.

Adjusting the pump to fit the application specifications results in less wear and tear on the rotor-stator since these are the primary wear parts on this style of pump. Monitoring and adjusting the line pressure helps the contractor double or even triple the life of these components. To further minimize lifetime maintenance costs and unnecessary downtime, some OEMs design their adjustable rotor-stator pumps with easy access to mechanical seals. This user-friendly design allows operators to perform mechanical seal maintenance without dismantling the rotor and stator, drastically reducing labour expenses and saving hours of unnecessary downtime.

Price Point
No product selection discussion would be complete without touching on price. Cost is an important factor in determining the value a piece of equipment brings to a business and whether it’s worth pursuing. In the past, a limited selection of gypsum mixer/pump models meant contractors looking to invest in gypsum equipment might be stuck with a higher price tag and unnecessary features for their operation. A lack of specialized gypsum equipment options also led some contractors to purchase units designed for more general cementitious applications — a situation that came with its own host of problems. However, as the gypsum industry continues to develop, more economical mixer/pump options with simpler and more user-friendly designs are filling the gap, offering contractors the ability to select equipment based on their needs without overinvesting.

in terms of capacity and output, contractors will find minimal difference between most gypsum machines. The industry average is 12-cubic-foot mixers and pumping speeds well over 100 bags of gypsum per hour. Differences arise with a closer inspection of the spec sheets. Contractors looking to not pay for more than they need should contact manufacturers to walk through what features are necessary for their specific operation. For example, engine size can play a huge part in price differentiation. Gypsum mixer/pumps range in size from 3,350 pounds (1,520 kilograms) with a 32-horsepower engine to nearly 10,000 pounds (4,536 kilograms) with a 100-horsepower engine. Exactly how much horsepower is necessary will depend on the target applications, so discussing options with OEM experts is important for making the most practical and economical decision. While gypsum mixer/pumps are not totally customizable, partnering with certain OEMs allows for a more personalized result, often with a significant cost savings over standard models.

Simplified Design
The saying “less is more” often applies to gypsum mixer/pumps. In addition to reducing the initial cost, selecting a reliable gypsum mixer/pump that does the basics and does them well often results in a user-friendly unit that’s easy to operate, maintain, and keep clean.

To make the most of an equipment investment, the machine needs to have high utilization. For contractors looking to operate at multiple jobsites with multiple crews, selecting a gypsum mixer/pump with the essential components and no frills equates to less training, less downtime and less stress. Machines with a simple, intuitive design are easy to operate with minimal training. This opens up the door for maximum productivity since contractors can train several crew members and still deliver quality results.

Fewer moving parts also means less mess and less maintenance. A unit’s mixer is a good example of this. Most units feature either a paddle type mixer or a hydraulic spiral mixer. Both work quickly, mixing a full load in about two minutes. However, hydraulic spiral mixers offer a benefit over paddle mixers since they can operate at higher speeds without splashing or throwing material out of the mixer. This leads to increased productivity since crews are not spending unnecessary time cleaning. Additionally, the paddle-style mixers used in gypsum equipment usually have two mixer shafts, which doubles the moving parts. Compare this to a single planetary gearbox driving the spiral mixer. With features like spiral mixers, new gypsum mixer/pumps limit possible maintenance issues and unnecessary downtime by minimizing moving parts.

These time-savings aren’t limited to major maintenance. Proper cleaning is vital for any concrete pump, including gypsum equipment. The less there is to clean, the faster this process will be. Look for a model with easily accessible wear parts to make daily cleaning as efficient as possible. Some manufacturers have gone a step further to simplify maintenance by engineering a removable mixer and pump kit that simply detaches from the machine for the ease of cleaning and scheduled maintenance.

Using a gypsum pump is a skilled task, but better designs include user-friendly features, such as easily accessed seals. Easy flow adjustment is also an important time-saving feature.

Manoeuverability
Transportability is another key consideration when selecting the right mixer/pump combination. The larger and more remote the contractor’s service area, the more vital this becomes. Units featuring robust trailers for long-distance travel and a lighter footprint provide a more practical solution for extended service areas. For maximum maneuverability, look for a unit with a dual-axle high-speed towing trailer and tubular steel frame to enable safe travel on highways.

Onsite manoeuverability is another area to keep in mind. Once the equipment has arrived, its placement and use can be quite the logistical challenge — especially on crowded jobsites. A gypsum pump with a smaller footprint can increase overall productivity. The charging process for different machines is a good example of this. Some models include a skip hoist to charge the mixer. The hoist is filled with sand and gypsum either by hand or with a skid steer bucket. When full, it rises and dumps into the mixer. This system requires sand and gypsum material to be stored near the pump and ample space for the hoist to manoeuver, limiting where contractors can set it up. Gypsum pumps without the skip hoist eliminate the additional step and can be charged directly with a specially designed skid-steer bucket. This not only saves time and energy, it allows contractors to set up sand and gypsum stockpiles in a separate location when space is at a premium.

Customer Service
As with many equipment decisions, brand is an important factor to consider when selecting a gypsum mixer/pump. The right machine will ultimately be the one with the ideal combination of features and price, but the service and support behind that unit can’t be discounted. Partnering with a manufacturer that has a reputation for robust, high-quality machines means operators can expect fewer breakdowns over its lifetime. Plus, when parts and service are required, knowing the team behind the brand is available 24/7 can be a huge relief. From fast delivery of parts to expert troubleshooting, dedicated OEMs help their customers increase efficiency.

MAKING THE RIGHT SELECTION
The surest route to success in any business starts with investing in the best equipment to get the job done quickly and efficiently. Recent advances are making it easier and more economical for first-time and veteran gypsum contractors to take this step, but there are still many factors to consider. From design to durability, selecting a gypsum mixer/pump for maximum productivity and profitability must begin with the contractor’s unique needs.

There are still relatively few certified gypsum concrete applicators around. But the sector is growing. With the booming construction market (when it gets going again) for multi-unit residential housing and the advances in gypsum concrete technology, it is a technology that is sure to be on the rise.


About the Author
Tripp Farrell joined Blastcrete Equipment, LLC in 2000 and serves as president. In addition to his responsibilities in sales, he works in product design and conducts product demonstrations and training. He is also involved in advertising and marketing of the Blastcrete product line, as well as research and development and, most importantly, customer service.

About Blastcrete Equipment
Blastcrete Equipment, LLC has been manufacturing safe, reliable and user-friendly solutions for the refractory and shotcrete industries for nearly 70 years. With a complete product line consisting of concrete mixers, pumps and related products, the company serves the commercial and residential construction, ICF and SCIP building systems, refractory and underground markets.