The demand for waterproof coverings for water silos is increasing every year. Coverings are mainly used to keep leaves, airborne dirt, and dust out of the water and to prevent algae growth and evaporation. But perhaps more importantly, to keep diseases and fungi such as Phytophthora out of the stored water.
In recent years, it has become increasingly apparent that there are more and more different PVC coverings on the silos at greenhouses, including tension covers in the form of a pointed roof or a round covering (domes). Growers have deemed that a positive development in horticulture.
Bas van der Elst from Hendic adds that a corrugated water silo is not designed for a covering. "After all, the strength of the silo is calculated based on water pressure from inside to outside. When a cover is placed on it, a different wind load occurs. Various systems have been developed to absorb these loads on the silo. Because the steel plates of the roof are very stiff and the weight of the snow load is distributed over the entire silo edge with support arms to the second ring, it makes it very solid. The pole in the middle provides additional support." Because the steel roof is much flatter, it also puts a much lower wind load on the silo.
Why do people still opt for PVC coverings?
Bas knows the answer: "Mainly because of price," and there's nothing wrong with that. A covering made largely of PVC is simply cheaper than a fully steel-made roof. I just want to make companies aware that there are also steel roofs available."
HD Steelcover
Bas takes the opportunity to highlight Hendic's HD-Steelcover: "It can withstand a snow load of 120 kg per sqm. The steel roofs come with an official strength calculation, CE mark, and detailed installation instructions. These steel roofs are made of S600 steel and with a galvanization of 450gr per sqm (resistant to rust formation). And you can also choose a powder coating in any desired Ral color."
The steel roof standardly includes a lockable manhole, and, as an option, a fixed ladder can be provided. This is safely mounted to the silo's bolt sets and is equipped with fall guards.
The HD-Steelcovers are available in diameters from 1.89 to 14.72, and the standard silos do not need to be adjusted. So, they can also be placed on existing silos.
Bas van der Elst and Nicolle Peetom of Hendic
For more information:
Hendic 
Goirkestraat 1a
4885 KS, Achtmaal
Tel.: +31(0)76-5976665
info@hendic.nl
www.hendic.nl