Polythene and Netting
So the time has come for a replacement polytunnel cover, but which polytunnel cover do you need? There are so many polythene options on the market that it can become confusing.
Diffusion: You should think of the diffusion properties of polythene as clouds in the sky. Diffused polythene scatters the light as it passes through, allowing it to hit the plants from all angles. This ensures your plants will get an even amount of light and not have to grow towards any particular light source, thus avoiding one plant overshadowing another. Even clear films have a small level of diffusion.
Thermic Effect: This is the level of heat retention. Heat that builds up during the day is lost at night. The higher the thermic value of the polythene the slower the heat loss.
Thickness: The thickness of the polythene does not relate to how strong the polythene is or how long it will last, our polythenes have additives (IR, UVI and EVA) that take care of all that. Too thick and it will be difficult to fit and get the tightness, too thin and you run the risk of damage.
Light Transmission: This is the amount of light that passes through the polythene. Too much direct light can be detrimental to some crops and too little can hinder growth.
5 Year guarantee: All our polytunnel covers come with a five season guarantee, however this is not to say your polythene cover will need replacing every 5 years, covers lasting 12-14 years is not unheard of.
Clear Polytunnel Covers
Lumisol clear transmits up to 92% of the light. In the UK where light levels can be lower, a clear polythene allows more light to enter which in turn can bring picking time forward. Lumisol Clear manipulates the type and level of light entering the greenhouse to significantly improve crop hardiness, colour, taste and shelf-life.
Light transmission: Up to 92% Thickness:720g Thermic effect: Over 80% Diffusion: Less than 35%
Diffused Polytunnel Covers
A diffused polytunnel cover possesses high levels of light diffusion to scatter the light entering the greenhouse. This allows the light to reach the crop from all angles, making the distribution of light more even. In addition, the day and night highs and lows of temperature are smoothed out with the high thermic value of Lumisol Diffused. This highly effective combination helps to reduce crop stress and to improve crop uniformity in order to deliver the highest yields possible.
Light transmission: Up to 90% Thickness: 720g Thermic effect: Over 80% Diffusion: 90%
As a general rule, if you have significantly more clear days than cloudy days during your growing season then a light diffusing film should be considered, and if you have more cloudy days then the extra light transmitted through a clear film may be preferred.
Once you have decided which of our covers will best suit your location and crop, you will need to know how much to order. If you are unsure on the amount of polythene you need why not use our polytunnel cover calculator.
Netted Polytunnel Covers
Some plants prefer the environment a netted polytunnel can provide. The net cover can be used in addition to the polythene to reduce the temperature inside and provide shade or, used alone a netted cover will give your crops protection from wildlife and the elements, provide shade and give full ventilation.
Our in-house fabrication department can produce polytunnel net covers to any size. Our standard shade net covers are dark green with a 40-45% shade value (heavier shade values can be catered for). The net contains a UV inhibitor to prevent premature UV degradation.
For more information about our polytunnel Covers, or to speak to a member of our team contact us on 01282 873120