POLYTHENE | FOUNDATIONS | ALUMINIUM V TIMBER | CONSTRUCTION TIPS
THE
ULTIMATE POLYTUNNEL GUIDE
THE NUMBER ONE GUIDE TO TAKING YOUR GROWING TO THE NEXT LEVEL
MADE IN THE UK
EST. 1969
EA SY BUILD
POLYTUNNEL KIT BY FAR THE QUICKEST, EASIEST & MOST DURABLE POLYTUNNEL AVAILABLE.
5%
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POL DISCO YTUN U NEL NT KITS
GY O DISC
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616
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SCREW ANCHORS
Our unique, specially designed screw anchors take just 1-2 minutes to screw into the ground...
No specialist tools or skills required. Quick & Easy Polythene Fixing System.
Strong & Durable Aluminium Sliding Door, Door Frames and Base Rails. Galvanised Steel Framework using 32mm diameter tube. 7 YEAR GUARANTEE on a range of polythene covers (average life is 10+).
NO DIGGING | NO CONCRETING | NO MESS
FRUIT CAGE KITS Pests eating your hard earned fruit? Our fruit cage kits come with everything you could possibly need to protect your crop. Galvanised 25mm steel framework Door Netting and Fasteners
Why not
Request a copy of our 2016 Hobby Gardening brochure? Just visit our website.
Call 01282 873120 or Shop Online www.northernpolytunnels.co.uk NORTHERN POLYTUNNELS
HOBBY GARDENING
Check out our handy online instruction video Scan QR code or visit www.northernpolytunnels.co.uk/videos
20 1
REASONS TO BUY A
P O LYT U N N E L
Warmer growing environment
Step into any polytunnel and you’ll find that it’s barmy microclimate is noticably warmer than it is outside. The polythene traps heat, making it a great spot for growing crops that would usually struggle to produce reliable harvests in the UK.
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Extended growing season
Soil protected by a polytunnel will be quick to warm up in spring, letting you sow seeds weeks earlier than would be possible outside. The higher temperatures reach right into autumn, increasing the amount of time slow maturing plants have to crop.
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Reliable conditions
It’s well worth keeping an eye on your thermometer, but remember that wind, rain, hail and drought can damage plants just as much as a temperature drop. A polytunnel climate is entirely under your control - just be sure to choose a model with a strong frame, able to stand up to the weight of snow. The hoop diameter is specified with all polytunnels, and is relevant to the overall strength of the structure, the thicker the hoop the stronger it tends to be. Standard hoop diametre ranges from 25 - 32mm. Northern Polytunnels supplies the thickest of 32mm as standard.
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Much cheaper
Any good polytunnel is far less expensive than a greenhoouse of the same size. This is either leaves you with more money in your pocket, or you may choose to get a bigger polytunnel or additional extras like irrigation systems and raised beds.
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Allotment sized options
Tiny plot or garden? Never fear. Most manufacturers make garden polytunnels as compact as 8ft wide by 10 ft long and goes right up to 14ft wide by 60ft long.
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No planning permission
Sheds and greenhouses don’t usually need permission from the local planning office and polytunnels generally fall into this category too. There are a few exceptions, for example if you live in a listed building or an area of outstanding natural beauty. If in doubt, contact your local planning office for more information.
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Save money
Growing your own fruit and veg instead of buying them at the local supermarket has proven to reduce your shopping budget by at least £500 per year, with the added exercise you can cut your gym membership too.
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20 REASONS TO BUY A POLYTUNNEL
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Simple construction
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Improved design
Most mid-sized polytunnels take a few days to construct (with 2-3 gardeners) and they usually come with detailed instructions. Northern Polytunnels Easy-Build Polytunnel takes half a day with 2 gardeners, it comes with comprehensive photo instructions and has the option of viewing a useful online video guide.
Traditionally, the sides of the polythene cover were buried or trenched into the ground to hold them in place, which required quite a bit of digging. These days, base rail systems can be teamed up with foundation tubes to offer stability with little spade work. Want to ditch the spade entirely? Look for screw-in anchors - no mess, no fuss, no concrete.
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Can be moved
Years of growing plants on the same spot could lead to a build up of pests and diseases. Crop rotation and good garden hygiene should be enough to keep your polytunnel soil problem-free, if not you can simply move it to another spot... or a different home entirely.
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Good for slopes
Greenhouses struggle on land that isn’t prefectly flat. Polytunnels can cope on a slight slope with no expert help. Depending on your ground tubes and fixing systems you can raise the hoops slightly on one side to compensate for the gradient. Northern Polytunnels Easy-Build Polytunnel has a unique system that works well for this, as a bonus it will also add extra tension to your polytunnel to create a drum-skin tight finish.
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More standing space
Traditionally, the hoops were semi-circular leaving little to no head room at the sides. Now, the hoops have been improved to have straight walls, meaning you have the freedom to move around easily without any bumps. This is also great for your climbing plants like tomatoes and peas, which can be suspended from crop/brace bars.
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Great ventilation.
You may have chosen polythene instead of glass, but the Greenhouse Effect still applies. In the middle of summer plants can suffer in the heat. Vents can be added to your polytunnel to allow fresh air in, with netting on the inside it will keep unwanted intruders out. Fans can be added to circulate air, as hot and humid air can linger in the centre of larger polytunnels.
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Keep insects out (or in)
As gardeners, we want to encourage pollinators into our growing environment and stop pests at the same time, which is why most good polytunnels with vents will come with netting. When you want to allow some beneficial wildlife in, simply open the doors.
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20 REASONS TO BUY A POLYTUNNEL
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Stands up to high winds
If you have a breezy plot, you might be concerned about the stability of a polytunnel. Thankfully, most polytunnels can withstand over 60 mile per hour winds, with the option of adding brace bars to add extra support. Brace bars stretch across the inside of your hoops, and have the bonus feature of being a handy place to hang plants.
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Year-round harvest
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Aluminium
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Multifunctional
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Guaranteed long-lasting polythene covers
A polytunnel will offer some protection from light frost, allowing you to enjoy a selection of winter veggies, plus leafy crops at the coldest times of the year. Insulation, cloches and heaters will keep your plants extra snug even in the snow.
Traditionally, polytunnels took days to construct and needed some on-site carpentry skills, as the only option available was to have timber base rails, door frames and doors. All needed to be measured, cut and secured into place with nails. Now with the Northern Polytunnels Easy-Build Polytunnel, pre-cut aluminium replaces timber, so it is easier and less time consuming to erect.
Polytunnels aren’t just limited to a single gardening job. You can dry fresh garlic bulbs and herbs, install a potting bench and use the warmer climate to propagate seedlings before you move them outside in spring. Some people have even been known to use a larger polytunnel to cover an outdoor swimming pool or to dry laundry.
Polytunnel covers will not need to be changed regularly, and have been known to last up to 15 years when kept in good shape. The lifespan of a polythene cover is determined by the quality, NOT the thickness. Most manufacturers will offer a guarantee with polythene (usually 5 years). Due to the nature of a polytunnel, algae can build up over time but this can be removed easily with some cleaning solution. Cleaning is best done in February and March before spring kicks in. We recommend Polytex Pro.
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Spoilt for choice Clear, diffused, SuperLux 50:50, white, green, bubblewrap, depending on your
growing needs there are a range of different polythenes on the market. For general UK growing we would suggest Superlux 50:50 which is a nice middle ground polythene. Live in Scotland or the North of England where you may have more cloudy days than bright? Maybe a clear polythene would work best to allow the most of the precious sunlight into your tunnel. We recommend Lumisol Clear. Lucky enough to live in a location with alot of sunshine and with it high UV levels? Diffused polythene may work best to protect your plants from scorching, we recommend Lumisol Diffused. This is just a general guide, and will depend on what you’d like to to grow, but you get the general idea.
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TAKING YOUR GROWING
TO THE N E XT LE VE L There’s alot to consider when making the decision of growing undercover. This handy guide will help you decide whether a polytunnel is for you, debunk some polytunnel myths and explain some of the jargon. Ready? Lets get started. POLYTHENE The plastic sheeting used to cover your polytunnel comes in many forms, the most popular are clear, diffused or a mid-range 50:50. Clouds act as a natural UV barrier which means it will reduce sunlight entering your tunnel, on the other hand, too much direct, harsh sunlight can have a negative affect on plants. The general rule of thumb is if your weather is; mostly cloudy - go for a clear polythene like Lumisol Clear. mostly bright - go for a diffused polythene like Lumisol Diffused mixed climate - go for a mid-range polythene like SuperLux 50:50 (popular within the UK). The lifespan of a polythene cover is determined by the quality, NOT the thickness. This is due to huge advances made in the horticulture industry, polythene made 15 years ago may have been 800g, now it can be 600-720g for the same strength of polythene. Most UK suppliers will offer a 3-7 year guarantee on a polythene cover. HOW TO ATTACH YOUR POLYTHENE There are a few ways to attach your polythene and each manufacturer has a different system. Traditionally you would dig 30cm deep by 30cm wide trench around your polytunnel and lay the polythene in it. Then backfill and tread the soil down to get the polythene tight. This requires a decent depth of earth and a huge amount of work. Now you can opt to attach it to base rails which does not require trenching or digging. Wooden base rails are clamped to the base of the hoops. The cover is pulled tight over it and is battened down on the outside. This means that the tensioning of the cover can’t be adjusted later so must be right first time. The result is a ‘hand tightened’ cover. Aluminium base rails don’t require nails, instead the cover is attached with plastic inserts. Northern Polytunnels Easy-Build has developed a ‘Wiggle Wire’ system that is quick to insert into a groove running along the length of the base rail. This system makes it easy to adjust the polythene as you go. Tensioning your cover after it has been fitted is only currently possible if you opt for the Easy-build Polytunnel by Northern Polytunnels. This is due to the fact that the Easy-Build’s base rails are attached to it’s ground tubes, the hoops sleeve over these tubes and can be raised up and locked into position after the cover has been fitted. This tightens the polythene creating a drum-skin tight finish. Getiing a your cover as tight as possible is important as wind can damage a loose cover and dramatically reduce it’s life span.
4 1
TAKING YOUR GROWING TO THE NEXT LEVEL
FOUNDATIONS There are few things to consider when choosing foundations. What kind of surface will you be building on? How much time and effort you want to put in and do you want to use concrete? Many allotments within the UK prohibit the use of concrete so it is well worth asking your allotment manager what the restrictions are. Foundation type
Digging Concrete
Screw Anchors Traditional ground tubes
AV. Time
Strength (5 = strongest)
10 mins
4/5
5 mins
1/2
Concreted ground tube
2-3 hrs
5
Ground Anchor plates
2-3 hrs
2/3
Base Plates
1-2 hrs
4/5 (if attaching to existing concrete)
Timescales depend on soil type and are based on using a quick setting concrete.
SCREW ANCHOR
TRADITIONAL GROUND TUBE
CONCRETED GROUND TUBE
GROUND ANCHOR PLATE
BASE PLATE
Screw Anchors pros: strong | no mess | no concrete | no digging | quick & easy cons: not suitable for rocky surfaces or loose ground that has been recently distrurbed Traditional Ground tubes pros: quick & easy cons: not recommended due to weakness and instability | difficult to get the cover tight Concreted Ground tubes pros: strongest all round option cons: more work, time & expense | longer to complete | not permitted on many allotments Ground Anchor plate pros: no concrete cons: digging and infilling | loosened backfill means this is a weaker option
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TAKING YOUR GROWING TO THE NEXT LEVEL
VENTILATION Ventilation is very important for the health and productivity of your polytunnel. Disease and algae thrive in the moist, stale air that can accumulate in the centre of larger polytunnels. Too much humidity and stale air can be very damaging to your plants, as well as making it an unpleasant working area for you. Even with good ventilation the summer temperatures can reach in excess of 40ÂşC. You can choose to section off your plants by how they react to heat and humidity. Keeping more delicate and cool loving plants nearer to your ventilation. For example, aubergines like warmer conditions than tomatoes whilst both prefer less humid conditions than cucumbers. A divided polytunnel also allows you to water accordingly too, so you can set up automated irrigation and control how much water goes to each section of your polytunnel. VENTILATION OPTIONS Of course, you have the option to leave your door open during warmer days. This option is best suited to smaller polytunnels that have ventilation panels or doors at both ends. Keeping your doors open has the advantage of allowing pollinators into your polytunnel which is great for your plants, however the downside of this is that it will also allow pests and other unwanted elements in aswell. Side ventilation is a great option of keeping your polytunnel ventilated. Side ventilation almost always comes with netting on the inside. Look for ventilation that includes a roll-up mechanism that keeps your side panels neatly rolled away to avoid damage. A sudden gust of wind or family pet can play havoc with loose polythene.
VENTILATION TIP We would recommend side ventilation on both sides of your polytunnel especially in warmer parts of the UK. This allows air to travel straight through keeping a steady flow of good, clean air into your polytunnel, whilst removing stale humid air at the same time. FANS As you know hot air rises, so ventilation alone may not be enough to keep the temperatures down during the height of summer. An air circulation fan will preserve a constant climate that will keep your plants drier giving less opportunity for diseases to develop. The size and power required will depend on the size and length of your polytunnel. Most smaller tunnels would be looking at a fan of around 460m3/hr. POLYTUNNEL EXTRACTION FAN A relatively new product to hobby growing, this award winning fan is installed at the top of your polytunnel and exhausts excessive heat up and out through a vent cut out at the roof. Currently availble from approximately ÂŁ230 from www.northernpolytunnels.co.uk.
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TAKING YOUR GROWING TO THE NEXT LEVEL
IRRIGATION Even the most amateur of gardeners will know, water is one of the most important aspect to all life. Which is why, when growing under-cover where there is no chance of rain, you have to have a relaible system in place to give your plants the water they need to survive. If you are of the forgetful disposition, have weekends away or find yourself without time during the week, perhaps automating your irrigation with timers would be the best option. Luckily there are lots of irrigation options availble to suit all bugdets and needs. Here are just a few: The trusty Watering Can The method of hand filling & watering with a metal or plastic can. Great for: if you want a low-cost option that gives you lots of time to talk to your plants. PROS: traditional, hands on watering | allows you to water only where it is needed CONS: you have to keep refilling it | labourious | time consuming due to limited flow rate The Hose Pipe The method of attaching a hose to the tap and controlling spray and pressure manually. Great for: if you have an outdoor tap and want a low-cost way to water a large area. PROS: hands on watering | cheaper option for watering large areas CONS: ravelling / unravelling | time consuming | gets stuck & twisted | can be wasteful Pot or Growbag Drippers The method of installing spiked drippers at the base of each plant either turning the tap or setting the timer to allow it to drip for say 10 minutes 3 times a day. Great for: if you have a lot of pots or grow bags and want to save water & time. PROS: can be automated | allows you to water only where is needed | neat & tidy CONS: depending on how many pots you have it can take a while to set up (but once it’s set up you can forget about it) Drip Line Irrigation The method of laying out a line of several driplines or porous pipe along your beds and allowing water to flow through, drip watering rows of crops. Great for: it you have beds and want to save water and time. PROS: can be automated | allows you to water only where is needed | water efficient CONS: not great to look at at first, but once plants start to grow they will be covered. Overhead Sprinkler The method of installing sprinklers to the ridge bar at the top of your polytunnel. Great for: if you have to water large areas quickly and consistantly. PROS: can be automated | allows you to water large areas at once | consistant watering CONS: Sprinklers will also water walkways and other surfaces, meaning it is not the most water efficient option.
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screw in
hoop
collar
raise the hoop on the foundation tube and lock into place with the collar provided.
top hoop will be higher than the bottom in line with the slope. Use a spirit level to ensure hoops are level.
hoops need to be at equal height
Raise hoops on foundation tubes and secure with collar. Use spirit level to ensure hoops are even horizontally and vertically.
WHY CHOOSE
NORTHERN
POLYTU N N E LS We are the pioneers of polytunnels. With the growth of popularity for home gardening and sustainable living back in the 60’s and 70’s, we were at the forefront of polytunnel design and manufacture in the UK from as early as 1969. We have been honing our craft for almost 50 years. Now with our talented design and engineering team we have remained at the pinnacle of innovation, replacing timber with aluminium and creating the strongest, easiest and most durable polytunnel on the market. Over the years we have had the pleasure of working with the BBC, River Cottage, Kew Gardens, The National Trust and National Botanical Gardens to name but a few. We love polytunnels, which is why our dedicated sales team are on hand every step of the way, from purchasing the perfect addition to your kitchen garden to talking you through the last nuts and bolts of construction.
Innovation Aluminium Our Easy-Build Polytunnel is an innovation in the current market. We are the only polytunnel manufacturer that has replaced all timber components with aluminium as standard, making banging in nails and sawing lengths of wood a thing of the past. Much more than just stronger and easier to construct, aluminium is more durable and withstands the elements without deteriorating. Timber (even treated timber) has a limited life and has a number of natural flaws - knots, splits, warps & twists, this means at some point rotted / damaged wood will need to be replaced. Sliding Doors Due to the problems we’ve seen over the years with hinged doors sticking, blowing off, and blowing open against the polytunnel cover, we now only supply aluminium sliding doors with our polytunnels. Polythene Tensioning System Our unique tensioning system allows the hoops to be raised up on the foundation tubes (and locked in position) after the cover is fitted. This allows you to get a drum-skin tight finish. The tighter the cover the less susceptible it will be to wind damage, therefore extending the life of your polythene. Polythene Fixing System We supply our ‘Wiggle Wire’ polythene fixing system as standard. Secure, quick & simple to use, and easily unclipped if required.
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WHY CHOOSE NORTHERN POLYTUNNELS
Steel = Strength Large Diameter Tube Our Easy-Build polytunnels are manufactured from 32mm (1¼”) diameter steel tubing, which is galvanised both inside and outside to construction grade Z35. Some manufacturers only use 25mm tube. 2-Piece Hoop We will never compromise on the strength and durability of our polytunnels, which is why our hoops are made in two halves, the same as our commercial range. Using 2 piece hoops creates a stronger structure, able to cope with even the most extreme conditions. Some manufacturers use 3 or 4 piece hoops. This creates a weaker frame, which means support bars are then required to make it sturdy. Closer Hoops Steel is strength, so closer hoop spacing makes a stronger structure. We offer either 5ft or 6ft hoop spacing on all of our Easy-Build polytunnels.
Aluminium or Wood? We briefly touched on the benefits of using aluminium in the Innovation section, here is a breakdown of our aluminium features: Aluminium Doors, Door Frames and Base Rails It’s stronger, easier to assemble (no carpentry skills required), and lasts a lifetime. Base Rails Our aluminium base rails have been designed with a groove running along it’s length, our polytunnel covers can then be fastened into the grooves using our unique ‘Wiggle Wire’ fixing system, making it easy to cover your tunnel single-handed. Quicker and easier than driving a nail into timber whilst keeping your polythene stretched or trenching your cover into the ground.
Foundations Heavy Gauge Foundation Tubes A polytunnel is only as strong as its foundations. We use thick walled (3mm), hot-dipped galvanized steel tube for longer life and a stronger structure. This is up to double the thickness of most other polytunnel manufacturers, making our foundations twice as strong. Screw Anchors Our screw anchor foundations provide superior anchorage whilst removing the need to dig or use concrete. No mess, easy to screw in, and installed in a fraction of the time.
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WHY CHOOSE NORTHERN POLYTUNNELS
Manufactured in the UK We have been designing and manufacturing polytunnels in the UK for almost 50 years. That’s how it’s always been and that is how it will remain.
Our dedicated Customer Service team Based in Lancashire, our customer service team has over 90 years of combined experience in polytunnel manufacturing, irrigation and construction for both hobby customers and commercial growers. They are on hand to help every step of the way from purchasing the right polytunnel straight through to wiggling your last “Wiggle Wire”. You can speak to them 5 days a week by telephone, email, social media and onilne chat facilities. Just call 01282 873 120 or email sales@npstructures.co.uk.
Instructions We include a comprehensive step by step photo instruction manual to help you build your
new polytunnel. Not into reading instructions? We also have detailed online instruction videos. Scan the QR code on the back cover or follow the link: www.northernpolytunnels. co.uk/video
Free Delivery We offer free delivery in 1- 5 working days for all polytunnel orders in mainland UK.
Don’t take our word for it, see what our customers have to say... We are currently rated 5 stars with Trustpilot check out our reviews at: www.trustpilot.com/northernpolytunnels
“ Excellent Product with Great Support Polytunnel arrived intact with all components present. Online video and instruction manual were easy to follow and when I did need assistance the guys at the office were very helpful. Very sturdy construct and looking forward to an extended growing season...”
“ If you want to buy a Polytunnel then this is worth buying I researched different polytunnel companies, I choose Northern Polytunnels and I would recommend them. They are really well made, the tubes are really are top quality, very helpful staff, ease of construction from a really well explained instruction manual with excellent self explanatory pictures, video backup on their web page.”
Request a brochure Online: www.northernpolytunnels.co.uk Phone: 01282 873120 Email: sales@npstructures.co.uk
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WHY CHOOSE NORTHERN POLYTUNNELS
Northern Polytunnels Average Time to erect (based on 2 people)
Half day (4-6 hours)
Closest Competitors 1-3 days depending on ability (some carpentry required)
Foundation Tubes
Heavy Duty galvanised tube with 3mm wall thickness to give protection from corrosion.
Pre-galvanised steel tube with a 1.5mm wall thickness.
Polythene Tensioning System
Up to 25mm tensioning.
None
Hoop Tube Diameter
32mm
25-28mm
Sections Per Hoop
2
3 -4
Steel Components Diameter
32mm
25-28mm
Base Rail
Aluminium
Timber
Side Rails
Aluminium
Timber
Door Frames
Aluminium
Timber
Door Operation
Sliding Aluminium Doors
Timber Hinged (sliding available)
Polythene Covering Options
Lumisol Clear Lumisol Diffused SuperLux 50:50
Various
Anti-Hotspot Tape
Supplied as Standard
Optional add on
Polythene Fixing System
Wiggle Wire: Quickest and option available on the market.
Timber laths and nails.
Side Vent System
Manual or Automated Wind-Up
Manual available through some suppliers
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Quality for life... www.northernpolytunnels.co.uk
NORTHERN POLYTUNNELS
HOBBY GARDENING
/northernpolytunnels
@NPolytunnels