Greenhouse Season Calls For Twin-Wall Polycarbonate

After this unusually brutal winter in many parts of North America, people are finally starting to “pick up the pieces” and are getting hopeful with the first signs of spring. With that, many gardening enthusiasts start to think of the work that needs to be done outdoors. For some, that may mean greenhouse maintenance or a new greenhouse altogether and if so, twin-wall polycarbonate should be strongly considered for the wall and roofing material.

Twin-wall polycarbonate is a corrugated economy grade of polycarbonate specifically designed for use in greenhouses and awnings. Unlike standard “smooth” polycarbonate, twin-wall comes standard UV stable on one side, meant to be installed facing outwards. Traditional polycarbonate sheets do not come UV-stable in their general-purpose form, commonly stocked by plastic companies. In addition, the twin-wall sheet is actually made up of plastic cells which help trap heat: critical for a greenhouse! The product is most commonly available in clear (which you would want for a greenhouse) but can be brought in on special order in bronze (more popular for outdoor awnings).

One important misconception about twin or multi-wall polycarbonate is that “thicker = better”. In general, that’s not true. The reason being is that users sometimes do not take into account that while the thicker material does trap more heat, it also lets in subsequently less light. So while you might have a warmer greenhouse you will also have one where the plants may take longer to grow and crop yields might be disappointing. Customers tend to find that large-scale industrial greenhouses use thicker multi-wall polycarbonate and assume this transfers directly to their application but that is an oversimplification: industrial greenhouse operations often have the benefit of artificial lighting to compensate for loss of light transference through the plastic. Something that most small home greenhouses do not have. For more information on this you might be interested in this blog post: Multi-Wall Polycarbonate: Beware Tradeoffs

We have found that 4′ x 10′ x 6mm clear twin-wall sheets offer the best balance of properties for home greenhouse applications. We have had satisfied customers from the wet coasts to the frigid northern prairies of Canada – so we believe for the home consumer thicker multi-wall may not be cost-effective for what you actually need.

For a quotation on twin-wall polycarbonate please contact us today.

Please let us know how many sheets you need, what size, and where you’re located for the quickest response.

Greenhouses and Awnings: Twin-Wall Polycarbonate

Spring has sprung across North America (finally) and people have started to turn their attention to outdoor projects. We commonly get asked about plastic sheeting for greenhouses and awnings, which ends up being the same product: twin-wall polycarbonate. This cost-effective, low-maintenance product excels in both commercial and consumer applications. In many ways, twin-wall polycarbonate has the potential to bring together the everyday consumer and industrial plastic.

Twin-wall polycarbonate differs from its smooth, glass-like sibling in a few key properties. Firstly, the twin-wall is made out of long “cells” that stretch down the entire length of the plastic. In essence, twin-wall is two parallel lengths of polycarbonate that are supported by these many walls. The product is also much cheaper than regular polycarbonate sheet and perhaps most importantly to the application itself, twin-wall polycarbonate is UV-stabilized while regular polycarbonate is not. That is an extremely important point, as regular polycarbonate will quickly discolor and crack within a few years of sun exposure. Twin-wall is not immune from weathering, but it usually takes 8-10 years before you start to see any effects with replacement common around 12-15 years.

While most smooth polycarbonate comes in 4′ x 8′ sheets standard and the thickness of the sheets also in imperial measurement, the twin-wall actually comes in 4′ x 10’s though other sizes are available. Twin-wall’s thickness is also measured in the metric system (millimeters) and this includes in the U.S. Twin-wall is easy to work with using household tools such as power drills or table saws. It does not require special hardware such as special screws to affix, 3/16″ screws from any hardware store are the most commonly used by our customers.

The thickness of the plastic is an important point to discuss. Many customers in North America request twin-wall that is thicker than required (8mm+). We stock 6mm only, and have had no complaints even from customers in Northern Canada. What people need to realize is that going with thicker twin-wall does not mean a “better” product for them. The heat insulation value (R-value) does increase; however, the light transmittance value falls. This is especially important in greenhouse applications as it means your plants get less sun energy the thicker you go!

For questions or a quote on twin-wall polycarbonate or help with our other products please contact us today.

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