Dec

What Polytunnel To Buy?

After checking out a number of polytunnel websites and weighing up options and costs, I decided that I would go with aluminium bars instead of wood to help reduce long-term maintenance. The following Polytunnel kit was ordered:

Polytunnel Size Width – 10ft Length – 20ft
Thermal Anti Fog Cover – “Thermal Anti Fog Polythene, 720 gauge (180 micron) 4 year UVI/EVA guaranteed polytunnel film, with added UV A and UV B filters. These filters dramatically reduce many fungal diseases, like mildew and botrytis. When water evaporation occurs, droplets (fogging) form on the inside of covers, eventually dropping back onto plants, which can cause damage and disease to young and tender plants. An anti-fogging agent incorporated into the film helps reduce this effect. It also contains an Infra-Red additive designed to reduce the speed at which heat dissipates out through the cover – in heated Polytunnels 15-20% fuel savings are achieved. A Thermic cover also helps to scatter light as it enters the Polytunnel.”
These specifications look good and I like the anti fungal and anti fogging properties especially with the humid summers we have been having.
Anti Hot Spot Tape Kit – The metal framework of your Polytunnel can become very hot, just like your car bonnet on a hot sunny day – sometimes it can be too hot to touch. Anti hot Spot Tape is a self adhesive tape that is placed over the Polytunnel’s hoops helping to prolong the life of the polythene sheet by at least one year. The slippery surface of the tape also allows the cover to slide effortlessly over the framework when erecting.
It seems a shame that such an important items is “optional” and hence an extra cost, but I think that it is worth it.
Crop Bar Kit - A steel bar is fixed across the hoops above head height. Can be used to support wires, canes, net and hanging baskets. A beneficial effect of crop bars is to strengthen the Polytunnel against wind on blustery sites.
I live on the top of a small hill and so my garden suffers from a lot of wind, which causes damage to fence panels and has even moved our 14ft diameter trampoline, so any additional strengthening of frame would be useful.
Storm Brace Kit – These braces are used on all the intermediate hoop joints to help strengthen the structure against wind on exposed or blustery sites.
Anchor Plate Kit - I do not want to use concrete and these anchor plates offer the best option also I want to use Base/Slide rails instead of digging in the poly cover. Once the anchor plates are in position, the plate will prevent lifting and sinking of the framework. This gives an easier, stronger and cheaper result than concreting. Framework can be assembled immediately as there is no waiting for the concrete to set.
Aluminium Base Rail Kit – These are strong aluminium extrusions, which is clamped to the base of the structure; PVC infill are then used to hold the flexible film materials (e.g. polythene or netting) into the aluminium extrusion. This system is ‘kind’ to polythene and the PVC infills can be removed (and reused) without damaging the polythene, this allows for correction of the polythene should it need re-adjusting. Replacing the polythene cover is simple as the plastic infills can easily be removed and re-fit – No more need for levering battens and nails from the framework or replacing timber when it eventually starts to rot!
That will do for me. Using Aluminium Base Rails instead of wood is initially expensive but I hope will be cheaper in the long run.
Aluminium Side Vent (Left) Kit – Aluminium Side Ventilation is a strong (double profiled) aluminium extrusion which is clamped to the side of the structure(approx 1-1½m high); PVC infills are then used to hold the flexible film materials (e.g. polythene and netting) into the aluminium extrusion. This system is ‘kind’ to polythene and the PVC infills can be removed (and reused) without damaging the polythene, this allows for correction of the polythene should it need re-adjusting. Replacing the polythene cover is simple as the plastic infills can easily be removed and re-fitted.
I have only ordered one vent kit, This will be placed on the sheltered side of the polytunnel away from the prevailing wind.
Staging (Right) Kit – “A simple and versatile staging support leg 30in high. Clamps easily to each hoop of your Polytunnel and comes complete with fixing brackets and clamps allowing a worktop of your choice.”
I have ordered one staging kit that will be installed on the opposite of the vent kit. I’m not sure how much of it I will use but at least I have kit to explore options.
Ground Cover Kit – “Cover the floor of your Polytunnel with squares for easy pot placement guaranteeing uniform plant growth. Tough and tear resistant. This ground cover effectively controls annual and perennial weeds. Its unique ripple weave technology allows excellent water dispersion making it easy to clean – just use a hose. Comes complete with enough to cover the floor area of you polytunnel along with fixing pegs.”
Weeds seem to easily defeat “standard” weed control matting, so I’m hoping with better results from this ground cover kit.
Super Upgrade – “Upgrade your Polytunnel to a higher specification by upgrading to a ‘Super’ a superior specification of tube is used for the Polytunnel framework. Normally supplied with 25mm steel the ‘Super’ model is supplied with 35mm diameter. This is more suitable for those very exposed and windy sites.”
Because of the high winds in autumn and winter, I felt that this upgrade was a good idea. There are many pictures on the web of collapsed polytunnels so erring on the side of caution.
Timber – Wide Door (Front End) – 2ft 11in wide x 6ft high. The top panel is covered in Shade Net to allow ventilation whilst the lower half is covered with polythene to prevent low-level draughts.
Timber – Double Door (Rear End) – With an opening of 4ft 6in wide x 6ft high. The top panel is covered in Shade Net to allow ventilation whilst the lower half is covered with polythene to prevent low-level draughts.
Irrigation Kit – I haven’t ordered any irrigation kit as I intend to install a couple of 220ltr water butts and auto pot systems. The filled water butts will help control temperature.