ga('create', 'UA-16038215-1', 'auto'); ga('send', 'pageview');
Home | Spray Foam Equipment | SPRAY RIG 101: What to Know Before You Buy
What to Know Before You Buy

SPRAY RIG 101: What to Know Before You Buy


Are you new to the spray foam market, looking to buy a new rig, or upgrade your old one? Choosing the right equipment can be daunting – from the configuration of the rig, to the equipment that fills it, how do you determine what fits your business model and your wallet? reached out to some industry experts to help clarify the process: Doug Kramer, President and CEO of Lapolla; Steve Loftis, Manager of Codes and Compliance for NCFI; George Spanos, President of Spray Foam Distributors of New England; Murphy Mahaffey, Director of International Sales, Polyurethane Machinery Corporation (PMC); Brett Adams, Marketing and Technical Support for Spray Foam Systems; John Davidson, Vice President of Operations for Spray Works Equipment Group LLC; Sara McKeon, Marketing Manager, Graco; Tim Nick, Sales Manager at; Jeremy Slosek, Product Manager at Christian Fab; and Jay Johnson, National Account Manager, CJ Spray Inc. With hundreds of combined years of industry knowledge, they can help simplify a labyrinthine process.

State Your Business

The first question to answer is: What are you going to be spraying? Sounds simple, but the ideal set-up differs from person to person and your day-to-day business will determine your rig. Steve Loftis, Manager of Codes and Compliance with NCFI, says, “Just as there is no one perfect auto, there’s no one perfect rig. A contractor in Florida will have different needs than a contractor in Colorado.” According to Tim Nick, Sales Manager with, there is a simple rubric to help focus the design question:

A.    Are you a homebuilder who will be relying on jobsite power?
B.    Are you a contractor who sprays mainly wall insulation with the occasional roof?
C.    Are you a contractor who sprays a mix of commercial and industrial roofs, air barrier systems, and large-scale projects?

Your answers will help determine many components, but first and foremost, the size and wattage of the compressor and generator that you choose. If you answer A, then chances are good that you can choose a rig with Shore Power, relying on electricity on the jobsite to power an electric compressor and generator. If you answer B, then you might want to look at gas compressors and gas generators. The output is greater, and so is the freedom. You are not at the mercy of jobsite power, which can be spotty. If you answer C, you have larger-scale projects and need greater power, then you might decide on the combination of a diesel generator and an electric compressor.

This rubric is handy, but a word of caution.

“You need to figure out if you want a generator that is big enough to run all your equipment, your compressor, your work lights, anything electrical,” says PMC’s Murphy Mahaffey.

Lapolla’s President and CEO, Doug Kramer adds that one of the biggest mistakes contractors make when choosing a new rig is that they start out too small and choose an undersized machine, even though they are warned: “We always say, ‘You’re only making money when the trigger is pulled’.” Often the contractors come back and get more hose and bigger machines.

Figuring out what you do and how much power you need to do it may be the most important decision in choosing your rig. As Sara McKeon from Graco states, “To get the most out of a spray rig, it is imperative to properly choose and correctly size the generator and air compressor.”

Graco provides a four-step process for determining the correct size generator:
1.    List system components that use peak load requirements in watts
2.    Add the wattage required by the system components
3.    Perform the following equation: Total watts x 1.25 = kVA (kilovolt-amperes)
4.     Select a generator size that is equal to or greater than the determined kVA   (Note: Use proportioner power cords that meet or exceed the requirement. Failure to do so will cause voltage fluctuations that can damage electrical equipment.)

The Rig Itself

Once you have determined the proper sizing of your generator and air compressor, focus on the rig itself. Will it be a box truck, tag-along trailer, gooseneck, or something else?

George Spanos from Spray Foam Distributors of NE, says that his company sells “99 box trailers to every one gooseneck.” He attributes this to several factors. The box trailers can be towed with any truck, whereas the goosenecks require a fifth wheel and special driver’s licenses. Moreover, box trailers are easier to move and maneuver. However, if you work large-scale projects, it is important to remember that the goosenecks do have the added benefit of more cargo space.

Brett Adams with Spray Foam Systems and John Davidson with Spray Works Equipment Group LLC, both mention the option of retrofitting their clients’ existing box trucks. However, in most cases, the cost (and benefit) of a new rig quickly outweighs the cost of remodeling the old rig. As Davidson says, “More often than not, they will ultimately opt for the new trailers, specifically tag-alongs, over the average retrofit because they tend to be more compact.”

NCFI’s Loftis cautions that the average trailer might not be the best choice, as “some jobs may require that the contractor drive down unpaved roads and travel down rough terrain.” This can be true even for residential contractors if the housing development has unpaved roads. He continues, “the axels must be able to carry heavy loads and the frame must be heavy enough to withstand drums and equipment banging around. They need to be designed to distribute the load evenly.”

Jay Johnson from CJ Spray concurs, stating that they “weight-engineer all spray foam trailer designs. This ensures that the trailer tows properly on the way to the jobsite full of product, and when it is empty of material on the way home.”

“The rig must be able to carry sufficient weight,” says George Spanos (Spray Foam Distributors of NE). “But some people don’t realize that the average truck Gross Vehicle Weight Rating (GVWR) of 7,000 lbs. isn’t enough to carry the weight that is necessary for a spray rig. Further, if the average rig has a total GVW of 9,900 lbs., the truck itself weighs 5,000 to 6,000 lbs. This means that we can only put 4,000 lbs. in the truck.” This weight limit and cargo capacity is of great import given the amount of material you will ultimately want to carry.

In addition to weight, is the rig’s ceiling high enough to permit changing out transfer pumps without tilting the drums? As Spanos says, “Six to eight feet is not sufficient interior height to remove the transfer pumps.”

Removing the pumps won’t be easy if you haven’t figured out the proper door configuration. Are your rig doors barn-style or are they ramps? A ramp-type door allows crews to easily roll the drums, manhandling them into the rig. However, the majority of the builders we spoke to preferred barn-style doors, stating that barn-style doors are more popular with their clients than ramps. The reasons given ranged from: Good in tight spots, easy to load with a forklift (and most serious contractors have forklifts), easier to deal with in bad weather, and as NCFI’s Loftis points out, can be quadruple hinged for added strength and reduced stress.

The rigs’ interior walls, ceilings, and floor can all be foamed. Not only will this maintain temperatures, but it will also add strength to the rig itself. The floor can be steel, diamond plate, spray polyurethane foam, or plywood, but remember that chemical spills and drips can damage the floor. Protecting the floor with an epoxy coating may be a solution. Jeremy Slosek of Christian Fab recommends, “plywood painted with regular paint as their rigs come with a lifetime guarantee.”

The necessary equipment will determine the interior design of the rig. The typical rig includes a sectioned off work area with a toolbox; a sectioned off area for the machinery (pumps, compressor, generator, etc.); and a material storage area.

It’s A Wrap

The exterior design of the rig is literally a blank billboard. While many of the shops do not have the capability in-house, each recommends a graphics designer who can design and create a custom wrap for the rig’s exterior. As Brett Adams says, “The rig is free bill board space, put the rig to work. We have contractor clients who have actually won jobs, while sitting in traffic, because of their wraps. One guy was at a dead stop in Atlanta traffic and had two calls go through to his office from people stuck in the same traffic. If you work on rehab construction, the rigs sit in neighborhoods and generate word-of-mouth buzz. If you work in new construction, the other subs will remember you and talk.” John Davidson agrees. “A clean, neat rig speaks for itself.” There is, however, a downside to the wrap, Adams cautions. “The world is full of bad people. Say you have your wrapped rig sitting in a parking lot. You’re advertising that the rig is full of very expensive spray foam. You can easily get robbed. So you must be secure at all times.”

Advice for the Do-It-Myselfer

You have an existing rig and you want to try your hand at retrofitting it yourself? Or you want to try outfitting one from scratch? We asked our experts for their Top Three Precautions for which the DIY Rig Restorer should look out. The consensus was:

1.    Make sure that the electrical work is preformed by an electrician
2.    Make sure that the proper weight loads have been calculated for your trailer
3.    Make sure the trailer is equipped with the proper safety gear.

Regardless of whether you retrofit your existing rig, upgrade to a new one, or are entering the industry for the first time, your spray rig is your mobile office and your lifeline on the jobsite.  Taking the time and effort to make an educated investment now, will pay off on current and future business.



1.   Is the equipment (engine, generator, air compressor, pumps, etc.) warrantied?

2.  How is the trailer constructed? Is it built to withstand the weight of heavy equipment and drums of material over time?

3.   What is the cargo capacity? What is the Gross Vehicle Weight Rating (GVWR)? Can the trailer support two or three sets of material, as well as a generator, compressor, plus one or two proportioners?

4.   Is the trailer equipped for proper weight load distribution? Proper weight load distribution keeps tongue weight at an acceptable level, promotes safe towing conditions and prevents swaying. Considerations need to be made for having full sets of chemical at the start of the day and returning with much less weight because the drums will be empty at day’s end.

5.   How is the floor of the spray rig finished?

6.   Vibrations from rough roads can damage equipment. Mounting the proportioner on shock-absorbing pads is a good idea to help prevent vibration damage.

7.   Is the spray rig insulated? Does it have an air conditioner and heater? Maintaining the chemical temperature is important to better control the reaction between A and B materials, leading to better material yields. In warm weather, an air conditioner helps prevent material overheating and expanding drums, keeping humidity at acceptable levels. In cold weather, a heater makes it easier to warm up materials to optimal spray temperatures.

8. Does the rig have a hose hatch? When you control ambient temperature conditions surrounding your materials, you get better material yield. If the spray rig door needs to be opened for the hose, the temperature will fluctuate, affecting the reaction between the A and B materials.

9.  What is the interior height? Ample headroom should be available to make it easier to change out a transfer pump without tilting the material drums.

10. Does the trailer have bogey wheels? Bogey wheels offer skid protection to the back end of the trailer to prevent trailer damage due to rough terrain.

11. Does the spray rig have a high-temperature air dryer? What is the maximum inlet temperature? A key piece of equipment in hot climates, an air dryer chills incoming air and removes moisture to prevent ISO crystallization. While most standard air dryers have a standard air inlet temperature of 140°F or 180°F, using a dryer with a 225°F inlet temperature, allows it to function in extreme temperature conditions.

12. Is the trailer equipped with a breakaway brake? Without a reliable breakaway brake system, trailer hitch failure could result in a runaway trailer – a dangerous highway situation that could lead to serious injury or even death. An important safety feature is to have safety chains and an electric breakaway brake system that will automatically apply the brakes on your trailer if it comes loose from the hitch.

13. Does the spray rig come with a spare tire?

14. What safety equipment is included with your spray rig? Fire extinguisher, eye wash station, first aid kit, etc.

Close Bitnami banner