More and more greenhouse entrepreneurs are investing in additional screens in the greenhouse. A great development that contributes to (the legally required) energy savings, but not all greenhouses are immediately suitable for a second or third screen. Sometimes, a modification to the greenhouse construction is necessary. How do you ensure proper installation and, thus, a successful, sustainable investment?
Thinking in solutions
"There are solutions that can be devised to make a screen adjustment responsibly," says technical specialist horticulture at Interpolis Theo Herngreen. He warns of potentially dangerous situations for both the greenhouse and the employees. "Not every greenhouse is suitable for a 2nd or 3rd screen. Greenhouse structures can be overloaded and thus damaged. The heavy load can cause the end wall to collapse from the tensile force, the gutter to twist away, or extra glass to break. Every screen installation has its own load. Whether this is a pull-push system or a pull-wire system attached and installed to the greenhouse gable. With each additional screen, additional force is placed on the end wall and, therefore, on the greenhouse deck. Ask yourself whether the gable columns and gutters can handle these extra forces. You will gain that insight with a strength calculation that takes the modified situation into account. Your greenhouse builder or structural engineer can help with this."
What strength calculations are needed?
A Casta or other structural calculation provides insight into the additional load and the strength required for the end wall and cross braces. This calculation can also provide insight into whether reinforcement of the greenhouse structure is needed.
Your greenhouse builder can help you with a GlazenStad calculation. This program calculates the extra load on the (end) gutters.
Connections in the right place and with the right quality.
It is important that the connections are in the right place. The extra screen installation causes the cross brace to sink further under the gutter. And are the cross braces still adequate? These affect the strength of the greenhouse. Again, these are points where your installer or greenhouse builder can help.
Do you have plans for an extra screen?
Then, involve your insurance advisor in time. Preferably before the purchase. They can advise you and put you in contact with an Interpolis risk expert or technical specialist. This way, you have access to knowledge about safe, strong greenhouses and a responsible and reliable installation of your 2nd or 3rd screen cloth.
Source: Interpolis