Polytunnel Parts.

Steel Specification

25.4mm x 1.2mm Wall Diameter - Z35 High Tensile Galvanised
35.0mm x 1.5mm Wall Diameter - Z35 High Tensile Galvanised
50.8mm x 1.5mm Wall Diameter - Z35 High Tensile Galvanised
60.3mm x 1.5mm Wall Diameter - Z35 High Tensile Galvanised

The length of swage for each tube are as follows:

• 25.4mm-51mm
• 35.0mm-70mm
• 50.8mm-83mm
• 60.3mm-90mm

The OD of a swaged tube are as follows:

• 25.4mm-22.0mm
• 35.0mm-31.0mm
• 50.8mm-46.8mm
• 60.3mm-56.3mm
• Should you require a different length, or with a flattened end or ends?
• A 'Flattened' joint creates a nominal loss in the length of 5mm - Example a tube 100cm long (1000mm) with 'Flattened Ends' at each end will result in a final length of 99cm (990mm). Flattened End for 60.3mm is not available.
• Please email us at info@highlandpolytunnels.co.uk  

• The aluminium rail joiner is required for connecting both single and double aluminium extrusions, meaning it’s a universal connector across the whole rail system — not all suppliers design theirs this way.

• It’s supplied as a pack of two, each with 3mm grub screws, which tells you the rails rely on a proper mechanical clamping system rather than simple push‑fit or overlap joints. This gives a stronger, cleaner finish.

🔧 Aluminium & Timber Base and Side Rail Fittings

Strong, universal fittings for securing polytunnel covers

We supply aluminium or timber base and side rail fittings designed for garden and commercial polytunnels. Available in 25mm, 35mm, 50.8mm, and 60.3mm, these fittings provide a reliable method of fixing the polythene cover to the frame — eliminating the need to dig trenches.

By locking the foundation tubes together as one continuous structure, base rails significantly increase the strength and stability of the polytunnel. They also make future maintenance easier, allowing the cover to be replaced quickly when refurbishment is needed.

These fittings are compatible with most polytunnel brands, offering a simple, effective upgrade regardless of the manufacturer.

We offer a wide range of brackets, clamps, and fittings suitable for both garden and commercial polytunnels, regardless of the manufacturer. Our available sizes include 25mm, 35mm, 50.8mm, and 60.3mm. All fittings are galvanised or zinc plated to ensure a longer lifespan. If you have any doubts or questions, please don't hesitate to contact us.

https://highlandpolytunnels.co.uk/replacement-tube-design-15095-p.asp

 🌱 A durable one‑piece plastic tie that provides a quick, reliable way to secure anything and everything around the garden. Every home should have a pack. Ideal for fixing netting, supporting plants, bundling materials, or tackling those everyday jobs where a fast, no‑nonsense fixing solution is needed.

Available in 20cm or 30cm lengths and supplied in packs of 100.

Simple to use — just thread and pull. Once tightened, they hold firm with a long‑lasting grip that won’t slip or loosen, even when used outdoors. Their flexible yet strong design makes them perfect for working with netting, mesh, or any material that needs a secure but non‑permanent fixing.

An essential item in any gardener’s toolkit.

We offer a wide range of brackets, clamps, and fittings suitable for both garden and commercial polytunnels, regardless of the manufacturer. Our available sizes include 25mm, 35mm, 50.8mm, and 60.3mm. All fittings are galvanised or zinc plated to ensure a longer lifespan. If you have any doubts or questions, please don't hesitate to contact us.

Our Foundation Tubes are designed specifically for use with our range of Polytunnels, featuring a swaged end for secure assembly. These tubes are suitable for quick and straightforward installation, particularly when constructing Polytunnels onto a soil base.

Installation Options

Foundation Tubes may be anchored directly into concrete for enhanced stability, or alternatively, they can be used in conjunction with Anchor Plates. Both methods provide reliable support for the structure, depending on site requirements and user preference.

Available Sizes

We offer Foundation Tubes in four different sizes to accommodate various specifications. Please refer to the table below for detailed information regarding each tube size.

The OD of the swaged end is as follows:

• 25.4mm with a .22mm swaged end.
• 35.0mm with a 31mm swaged end.
• 50.8mm with a 46.8mm swaged end.
• 60.3mm with a 56.3mm swaged end.

We provide various options for ground foundations or anchor plates, as well as base plates for concrete or timber, for both garden and commercial polytunnels. These options come in sizes of 25mm, 35mm, 50.8mm, and 60.3mm. For smaller tunnels, we also offer screw anchors in sizes of 25mm and 35mm. These options are compatible with most polytunnels, regardless of the manufacturer.

PLEASE NOTE: IF YOU ARE ORDERING THE ANCHOR PLATES, YOU MAY REQUIRE THE FOUNDATION TUBES TOO.

🔧 Material & Design Insights

• The PVC infill is designed to work with both single and double aluminium extrusions, meaning the manufacturer uses a unified rail profile system — great for repairs or upgrades without compatibility headaches.

• The top and bottom profiles are intentionally “kinder” to polythene or net, reducing abrasion and extending cover life. This is a subtle but important design choice for long-term durability.

We offer a wide range of brackets, clamps, and fittings suitable for both garden and commercial polytunnels, regardless of the manufacturer. Our available sizes include 25mm, 35mm, 50.8mm, and 60.3mm. All fittings are galvanised or zinc plated to ensure a longer lifespan. If you have any doubts or questions, please don't hesitate to contact us.

Click the links below for other parts.

Intermediate base and side rail fittings .

Ridge bars fittings.

Door frame brackets.

Q Clips

Anchor Plates provide a strong, reliable alternative to concreting and add extra security to your polytunnel structure. They are essential when fitting Base Rails or Side Rails, helping to prevent the framework from lifting or sinking over time.

Each square plate slides over the Foundation Tube (not included) and is secured at the base using two clamps—one above and one below the plate. Once buried, the plate locks the tube firmly in place, improving overall stability in a wide range of soil conditions.

Available in three sizes. Please refer to the table below for pack contents.

This 0.65 m crank handle is a practical, durable accessory built for effortless control of your polytunnel gearbox. It’s a smart and dependable addition to your gardening setup built to withstand regular use in greenhouse environments.

Growers using crank‑operated side vents typically see:

• Lower humidity spikes
• Reduced fungal pressure (especially botrytis)
• More stable temperatures
• This makes the crank handle indirectly responsible for healthier crops

Base Plates provide a quick, reliable method of installing a Polytunnel onto a timber or concrete base. They create sturdy ‘feet’ for the framework and are used instead of Foundation Tubes when ground‑dig installation isn’t suitable.

Each plate is manufactured to securely support the hoop and ensure a stable, long‑lasting structure.

Fixing Options

• Timber Base: Supplied with M8 × 50 mm screw bolts for fast, secure fixing.

• Concrete Base: Supplied with M10 × 75 mm Rawl bolts for heavy‑duty anchoring.

Hoop Compatibility

• 25.4 mm diameter hoops locate inside the Base Plate tube.

• 35 mm diameter hoops locate outside the Base Plate tube.

This ensures a snug, secure fit regardless of hoop size.

Please Note, Hoops with a diameter of 25.4mm will locate inside the Base Plate Tube. Hoops with a diameter of 35mm will locate outside of the Base Plate Tube.

Single Aluminium Extrusion (Base rail), available in a variety of lengths. We use this single profile on base rails for Polytunnels. Designed to accept 200 micron polythene and used in conjunction with our PVC infill and Rail Joiners.

Attached to the framework with intermediate and corner clamps.

Crop Bars are galvanised steel bars fixed across the hoops above head height to suspend wires, canes, netting, or hanging baskets. They also stiffen the tunnel structure, giving extra protection in exposed, windy sites.

How to Order

Choose three things:

• Polytunnel Width — select the internal width of your tunnel so the bar length matches.

• Q Clip size — pick the clip that matches your hoop diameter.

• Quantity — enter the number of individual Crop Bars you need.

• See below.

• The double aluminium extrusion is specifically designed for base rails, meaning it’s the heavy‑duty option in the rail system — ideal for areas where cover tension and structural strength matter most.

• It’s engineered to accept 200‑micron polythene, the industry‑standard thickness for long‑life polytunnel covers. This confirms the extrusion is built for proper grip and durability.

• The system relies on PVC infills and rail joiners, creating a professional clamping method that avoids rot, warping, and uneven tension.

Double Aluminium Extrusion, available in a variety of lengths. We use this double profile on base rails for Polytunnels. Designed to accept 200 micron polythene and used in conjunction with our PVC infill and Rail Joiners.  Attached to the framework with intermediate and corner clamps.

Please note, you will require the fixings mentioned. Click on the links above.

We offer a wide range of brackets, clamps, and fittings suitable for both garden and commercial polytunnels, regardless of the manufacturer. Our available sizes include 25mm, 35mm, 50.8mm, and 60.3mm. All fittings are galvanised or zinc plated to ensure a longer lifespan. If you have any doubts or questions, please don't hesitate to contact us.

https://highlandpolytunnels.co.uk/replacement-tube-design-15095-p.asp

Base Plates provide a quick, reliable method of installing a Polytunnel onto a timber or concrete base. They create sturdy ‘feet’ for the framework and are used instead of Foundation Tubes when ground‑dig installation isn’t suitable.

Each plate is manufactured to securely support the hoop and ensure a stable, long‑lasting structure.

Fixing Options

• Timber Base: Supplied with M10 × 50 mm screw bolts for fast, secure fixing.

• Concrete Base: Supplied with M10 × 75 mm Rawl bolts for heavy‑duty anchoring.

Our Aluminium sliding door track is manufactured from a heavy duty Alloy 6063 T6, as this is used for sliding doors on our Domestic and Commercial Polytunnel range. Sliding door track available in three lengths for attaching a single, wide and double sliding doors. Corner protectors are available to help protect the sharp corners. Please see table below for weight.

Gearbox and fittings for the side ventilation screen. The pack contains:

• Runner wheels (bogies)
• Face plate
• Gearbox
• Drive shaft (to fit 25mm diameter tube)
• Nuts and bolts

Crank Handle required to operate.

Our 6ft wide hoop is produced from 25mm galvanised steel tube as used in our 8ft wide polytunnel model. We offer a full hoop in four piece sections. We also offer individual sections.

Hoops simply slot together, allowing easy storage when not in use. A permanent fix can be achieved through using Self Drill Screws. The hoops can be pushed into soft soil, or you can look at ordering additional Foundations for a more permanent and secure fitting.

A. Hoop Width - 6ft (1.83m)
B. Height - 6ft 10in (2.08m)
C. Straight Side - 4ft (1.21m)
D. Distance Over Hoop - 17ft 3in (5.25m)

Our 8ft wide hoop is produced from 25mm galvanised steel tube as used in our 8ft wide polytunnel model. We offer a full hoop in four piece sections. We also offer individual sections.

Hoops simply slot together, allowing easy storage when not in use. A permanent fix can be achieved through using Self Drill Screws. The hoops can be pushed into soft soil, or you can look at ordering additional Foundations for a more permanent and secure fitting.

A. Hoop Width - 8ft (2.44m)
B. Height - 6ft 8in (2.03m)
C. Straight Side - 3ft 3in (0.99m)
D. Distance Over Hoop - 18ft (5.48m)

Our 10ft wide hoop is supplied in 25 mm or 35mm galvanised steel. We offer a full hoop in four-piece sections, or individual sections. Please review all the images to find the one that suits you.

Hoops simply slot together, allowing easy storage when not in use. A permanent fix can be achieved through using Self Drill Screws. The hoops can be pushed into soft soil, or you can look at ordering additional Foundations for a more permanent and secure fitting.

10ft Wide Polytunnel Hoop
A. Hoop Width – 10ft (3.05m)
B. Height – 7ft (2.13m)
C. Straight Side – 3ft 2in (0.96m)
D. Distance Over Hoop – 20ft (6.09m)

Our 12ft wide hoop is produced from 35mm galvanised steel tube as used in our 12ft wide polytunnel model. We offer a full hoop in four piece sections. We also offer individual sections.

Hoops simply slot together, allowing easy storage when not in use. A permanent fix can be achieved through using Self Drill Screws. The hoops can be pushed into soft soil, or you can look at ordering additional Foundations for a more permanent and secure fitting.

12ft Wide Polytunnel Hoop
A. Hoop Width - 12ft (3.66m)
B. Height - 7ft 7in (2.31m)
C. Straight Side - 3ft 3in (0.99m)
D. Distance Over Hoop - 22ft 8in (6.90m)

Make your polytunnel project more straight forward with our comprehensive Base Rail Kits. These kits come with all the fittings, battens and nails you need for a professional-looking finish. Our retro fittings are compatible with polytunnels from any manufacturer, ensuring they fit perfectly on any project.  If your polytunnel is 12ft wide just choose the length from the 14ft wide list.

Please Note:  You must ensure that your foundations are set in concrete, alternatively you can use anchor plates or screw anchors.

Should you require larger fittings please contact us.

Our 14ft wide hoop is produced from 35mm galvanised steel tube as used in our 14ft wide polytunnel model. We offer a full hoop in four piece sections. We also offer individual sections.

Hoops simply slot together, allowing easy storage when not in use. A permanent fix can be achieved through using Self Drill Screws. The hoops can be pushed into soft soil, or you can look at ordering additional Foundations for a more permanent and secure fitting.

A. Hoop Width - 14ft (4.27m)
B. Height - 8ft 2in (2.48m)
C. Straight Side - 3ft 3in (0.99m)
D. Distance Over Hoop - 25ft 4in (7.72m)     

🎯 Roll‑Up Screen for Polytunnel Side Ventilation

Our Roll‑Up Screen is designed to give you easy, manual control over the side ventilation on your polytunnel. It allows you to open or close the netted side area as needed, helping regulate airflow, temperature, and crop protection throughout the growing season.

🔧 Installation Requirements

The Roll‑Up Screen is fitted to the inside of the windbreak netting, mounted on the timber side rail approximately 1m-1.5m above ground level. To install this product, your polytunnel must already have:

• A timber side rail

• Windbreak netting fitted along the side

If you require these components, please see our Polytunnel Side Ventilation options.

Not included in the kit.19mm x 38mm (¾in x 1½in) timber battens.
Typical Use: Used as a fixing batten when securing polythene on doors/frames and base/side rails.

What's in this kit? See below.

Our 16ft wide hoop is produced from 50mm galvanised steel tube as used in our 16ft wide polytunnel model. We offer a full hoop in three piece sections. We also offer individual sections. Hoops simply slot together, allowing easy storage when not in use. A permanent fix can be achieved through  using Self Drill Screws. The hoops can be pushed into soft soil, or you can look at ordering additional Foundations for a more permanent and secure fitting.

A. Hoop Width - 16ft (4.88m)
B. Height - 8ft 4in (2.54m)
C. Straight Side - 3ft 3in (0.99m)
D. Distance Over Hoop - 26ft 7in (8.15m)

Our 18ft wide hoop is produced from 50mm galvanised steel tube as used in our 18ft wide polytunnel model. We offer a full hoop in three piece sections. We also offer individual sections.

Hoops simply slot together, allowing easy storage when not in use. A permanent fix can be achieved through using Self Drill Screws. The hoops can be pushed into soft soil, or you can look at ordering additional Foundations for a more permanent and secure fitting.

A. Hoop Width - 18ft (5.49m)
B. Height - 8ft 6in (2.59m)
C. Straight Side - 3ft 3in (0.99m)
D. Distance Over Hoop - 28ft 7in (8.76m)  

Our 20ft wide hoop is produced from 50mm galvanised steel tube as used in our 20ft wide polytunnel model. We offer a full hoop in four piece sections. We also offer individual sections.

Hoops simply slot together, allowing easy storage when not in use. A permanent fix can be achieved through using Self Drill Screws. The hoops can be pushed into soft soil, or you can look at ordering additional Foundations for a more permanent and secure fitting.

A. Hoop Width - 20ft (6.10m)
B. Height - 9ft 4in (2.84m)
C. Straight Side - 4ft 6in (1.37m)
D. Distance Over Hoop - 32ft 5in (9.89m)

Our 22ft wide hoop is produced from 50mm galvanised steel tube as used in our 22ft wide polytunnel model. We offer a full hoop in four piece sections. We also offer individual sections.

Hoops simply slot together, allowing easy storage when not in use. A permanent fix can be achieved through using Self Drill Screws. The hoops can be pushed into soft soil, or you can look at ordering additional Foundations for a more permanent and secure fitting.

A. Hoop Width - 22ft (6.7m)
B. Height - 9ft 7in (2.92m)
C. Straight Side - 4ft 6in (1.37m)
D. Distance Over Hoop - 3ft 5in (10.53m)

Our 24ft wide hoop is produced from 50mm galvanised steel tube as used in our 24ft wide polytunnel model. We offer a full hoop in four piece sections. We also offer individual sections.

Hoops simply slot together, allowing easy storage when not in use. A permanent fix can be achieved through using Self Drill Screws. The hoops can be pushed into soft soil, or you can look at ordering additional Foundations for a more permanent and secure fitting.

A. Hoop Width - 24ft (7.32m)
B. Height - 9ft 10in (2.9m)
C. Straight Side - 4ft 6in (1.37m)
D. Distance Over Hoop - 36ft 5in (11.13m)

Strong, secure and built from pressure‑treated timber

Our Inner Doors are manufactured from 47mm × 47mm pressure‑treated timber, the same high‑quality material used across our Domestic Polytunnel range. Each door set includes:

• Two upright posts – 1.8m long

• Three cross pieces providing the following door widths:

  • 50cm (Single)

  • 70cm (Wide)

  • 120cm (Double)

  • Single‑row timber battens to securely clamp the polythene door panels to the frame

  • This robust timber construction ensures long‑term stability and a tight, weather‑resistant fit.

  • 🛠️ Sliding Door Support Rail

    A 47mm × 47mm pressure‑treated support rail is supplied to prevent the sliding door from rubbing against or damaging the polythene cover. Simply select the length required for your tunnel.

    The support rail attaches directly to the polytunnel hoop using a P Clip, included within the Sliding Door Support Rail Fixing Kit. Please select the correct P Clip size to match your hoop diameter.

Our 26ft wide hoop is produced from 60.3mm galvanised steel tube as used in our 26ft wide polytunnel model. We offer a full hoop in four piece sections. We also offer individual sections.

Hoops simply slot together, allowing easy storage when not in use. A permanent fix can be achieved through using Self Drill Screws. The hoops can be pushed into soft soil, or you can look at ordering additional Foundations for a more permanent and secure fitting.

A. Hoop Width - 26ft (7.92m)
B. Height - 12ft (3.66m)
C. Straight Side - 3ft 3in (1.00m)
D. Distance Over Hoop - 41ft (12.5m)

Our 28ft wide hoop is produced from 60.3mm galvanised steel tube as used in our 28ft wide polytunnel model. We offer a full hoop in four piece sections. We also offer individual sections.

Hoops simply slot together, allowing easy storage when not in use. A permanent fix can be achieved through using Self Drill Screws. The hoops can be pushed into soft soil, or you can look at ordering additional Foundations for a more permanent and secure fitting.

A. Hoop Width - 28ft (8.54m)
B. Height - 12ft 2in (3.71m)
C. Straight Side - 3ft 3in (1.00m)
D. Distance Over Hoop - 43ft (13.1m)

Our 30ft wide hoop is produced from 60.3mm galvanised steel tube as used in our 30ft wide polytunnel model. We offer a full hoop in four piece sections. We also offer individual sections.

Hoops simply slot together, allowing easy storage when not in use. A permanent fix can be achieved through using Self Drill Screws. The hoops can be pushed into soft soil, or you can look at ordering additional Foundations for a more permanent and secure fitting.

A. Hoop Width - 30ft (9.14m)
B. Height - 12ft 3in (3.73m)
C. Straight Side - 3ft 3in (1.00m)
D. Distance Over Hoop - 45ft (13.7m)