As spring turns into summer and the busiest part of the season slows down, now’s the time that many of you might be turning your budgeted renovation projects into reality. But whether you’re building a new greenhouse or retrofitting an existing structure, there’s one simple rule to follow: expect the unexpected.
A natural weather event can quickly wreak havoc on your expansion plans, but there are still ways you can plan ahead. Check out the next few pages for tips from greenhouse manufacturers on how to deal with these calamities.
In April 2015, one of the three Bergen Greenhouses at its Forest Lake, MN, location burned to the ground. The 12-acre structure was a total loss.
With the help of Rough Brothers, Bergen’s was able to build a new poly open roof greenhouse with a few modifications to accommodate the heavy snow load in the northern states. The open roof was designed with a deeper open-gutter design to provide durability and rainwater collection capacity. Also, the substructure was Hot Dip Galvanized to allow gutter posts to act as rainwater downspouts to keep the greenhouse interior less cluttered.
Shane Nitschke of Rough Brothers, who supervised the project on his company’s behalf, says Rough has regional salespeople throughout the U.S., and this geographic proximity allows for convenient interaction between the grower and the manufacturer, from the first consultation through design and finally during greenhouse construction.
“The face-to-face communication always leads to a simplified project,” Nitschke says.
How To Prevent A Catastrophic Fire
Note: This section was written by Lauren Schiele at NIP Programs.
In a greenhouse environment, quickly spreading fires will easily destroy crops, damage facilities, and disrupt business operations, resulting in lost income. These blazing flames are a result of high temperature, combustible materials, and oxygen — all elements commonly found within a greenhouse.
Flammable materials exposed to high temperature sources plant the seed for a fire disaster. Add oxygen to the mix, and your whole greenhouse operation could get destroyed. Sources of these high temperatures include poor electrical wiring, overloaded circuits, soldering or welding work, heating systems and other equipment, and discarded cigarettes. When a flame or high heat comes into contact with plastic, greenhouse covers, shade cloths, chemicals, and other flammable items, a fire can break out. Increasing the flow of oxygen, such as through a fan, only intensifies and spreads the flames.
To prevent these elements from coming into contact with one another and starting a fire, it’s important to minimize and control fire hazards within your facility. Below are some tips from the NIP Group (NIPGroup.com), which develops and manages business insurance programs, to protect your greenhouse, crops, and employees.
Build Your Greenhouse To Resist Fires
The first step to preventing a fire is to safeguard your greenhouse by complying with building codes and National Electrical Code (NEC) requirements. This ensures your facility is constructed to avoid fires, including installed sprinklers, proper electrical wiring and grounding, and location distance from other buildings.
The layout and design of your greenhouse also contributes to fire prevention. Layout and design tips include but are not limited to:
• Building a separate ventilated area, preferably outside of your facility, to store flammable liquids
• Placing heating systems, electrical equipment, and other combustion-type equipment a safe distance away from flammable materials
• Using non-combustible building materials for walkways and other appropriate areas
• Regularly inspect and control fire hazards
Have A Plan If A Fire Does Break Out
Response by your employees can keep a fire from spreading and causing significant damage. Create an emergency response plan with steps to take if a fire does break out, including how and when to use a fire extinguisher, emergency contact numbers to call, and where to exit the facility.
If the fire causes property damages or injuries, the right insurance coverage will protect your greenhouse business from significant financial loss. To get the best coverage for your operational and financial needs, it’s important to know the risks your business faces. You’ll also want to find out what is covered under each type of insurance policy.
Watch For High Winds
Note: These tips are provided by Rimol Greenhouses.
The constant threat of high winds is a reminder of the importance of making sure you are minimizing the potential for storm damage at your greenhouse. Withdrawal resistance, building orientation, and exposure are all factors to consider, and your greenhouse can act like a sail and pull the structure right from the ground if not secured and braced properly.
For example, an 80 mile per hour (mph) gust of wind can produce a pressure of 16 pounds per square foot (psf) on your structure. That means a 28-foot by 100-foot hoophouse withstanding these winds would be exposed to 220 pounds per square foot of length, or 22,000 psf on the entire structure. This is why building inspectors, to the dismay of many anxious growers, often require that ground posts be embedded in concrete. That is, dismayed until that first big storm hits and the greenhouse is still there with all the crops safe and sound inside.
5 Tips For Wind Loading
Protect your greenhouse from wind with these five tips.
• Close up all the openings, including vents, louvers, and the doors. Whatever outside force is applied to the high tunnel is doubled when allowed inside the building. In essence, the wind entering the structure will attempt to force the walls and roof outwards and upwards.
• Research the typical wind patterns on your property. The building orientation can reduce the friction and pressure on your tunnel when set up correctly. You want your tunnel to provide the least resistance possible.
• For air-inflated greenhouses, increase the pressure on the inside to reduce rippling effect of the poly. Double down and make sure any slits or openings are taped with film repair tape.
• Use windbreaks to reduce the wind speed or deflect wind over the greenhouse. Typical windbreaks are conifer trees such as hemlock, spruce, or pine at least 50 feet upwind from the greenhouse — far enough that falling limbs will not come into contact with the structure. Wood or plastic fencing can also be used as a buffer.
• If you have a metal chimney, stove pipe, or any exterior ventilation susceptible to high winds, secure them with sheet metal screws.
Don’t Let Snow Pile Up
Note: These tips are provided by Rimol Greenhouses.
Snow can be light and fluffy. It can also be wet, heavy, and destructive. For example, just 1 inch of rain is often equivalent to more than 10 inches of snow. For anyone who has shoveled after a snowstorm, 10 inches of snow — especially the heavy, wet stuff — is no small task to clear away. Without being removed, that weight is being applied directly to your greenhouse.
Here are five tips to consider:
• Leave at least 10 to 12 feet between individual greenhouses so snow can accumulate. This will also prevent sidewalls from being crushed in as pressure builds from added snowfall over the winter.
• If you have a heating system, it should be equipped to maintain a temperature of 60°F to melt snow and ice and prevent excessive build up. Make sure the heat is turned on at least a couple hours before the storm begins.
• Pull energy screens aside to allow heat to get to the glazing and melt snow and ice.
• Make sure you have diagonal bracing to keep the greenhouse from racking from the weight of snow and ice. If you don’t already have this installed, consider retrofitting your structure. It will add years to your investment.
• Keep the following three items on hand:
Durable lumber to brace your structure and complete temporary repairs
Brooms to help push snow off of poly structures without damaging the cladding
Backup poly for temporary repairs and to ensure heat is retained to protect crops
A little preparation can go a long way to minimize damage from severe weather events such as blizzards, windstorms, and ice storms. Make sure that your environmental controls are working properly to heat snow and ice from the inside and prevent build-up. And just as important, have a well-stocked generator in case you lose power.