Galvanised steel greenhouses
for exposed British plots.

No greenhouse is guaranteed against every weather event. SteelRoot uses a closed RHS galvanised steel frame, screw-fixed twin-wall polycarbonate and included ground anchors; 1 m is the standard arch spacing and 0.67 m is the close-arch option.

Damage from named storm events or other extreme weather is excluded. The product warranty is: 2-year manufacturing defect warranty on cellular polycarbonate panels + 10-year anti-corrosion warranty on the galvanised steel frame. See our warranty page for the full terms. For coastal, upland or otherwise exposed plots, email us before ordering.

1.0 m is the standard arch spacing. The 0.67 m close-arch option adds more frame-to-panel intersections along the length, so unsupported polycarbonate spans are shorter and panel movement is reduced.

Choose 1.0 m for the base specification, or 0.67 m when your site is more exposed or you want the shorter-span build. Correct anchoring and ground conditions still matter in either configuration.

Two adults, no specialist tools. The frame is pre-drilled and bolt-assembled, with components arriving numbered and grouped by build stage. Realistic build times working at a comfortable pace:

4 m 1 to 2 days · 6 m 2 days · 8 m 2 to 3 days · 10 m 3 days · 12 m 3 days.

You need a cordless drill, spanner set, spirit level and step-ladder. A QR-code-linked build video covers the sequence. The base and fixing method must suit the installation site.

Ground anchors are included with every SteelRoot. The anchor schedule depends on the selected length and installation conditions, so confirm the supplied layout in your order specification and follow the included installation guide.

Correct anchoring matters for wind performance. If your ground is loose, made up, paved or unusually exposed, send us photographs before ordering so the installation can be checked.

The frame is 40 × 20 mm rectangular hollow section galvanised steel with ZAM coating (zinc-aluminium-magnesium). Avoid grinding or drilling new holes after the build because every required hole is pre-drilled at the factory.

The product warranty is: 2-year manufacturing defect warranty on cellular polycarbonate panels + 10-year anti-corrosion warranty on the galvanised steel frame. See the full warranty terms before ordering.

Both 4 and 6 mm twin-wall polycarbonate are offered on SteelRoot. The 4 mm panel is the base specification; 6 mm is the stiffer, warmer option.

Both thicknesses are UV-stabilised and screw-fixed at every panel edge with stainless screws and EPDM washers. Choose 6 mm when extra stiffness or thermal retention matters more than the lowest entry price.

Cross-ventilation comes as standard: the opening rear window sits opposite the door, giving you airflow through the length of the greenhouse. Automatic vents are optional accessories and are sold separately.

For hot, south-facing plots, open the door and rear window early, use greenhouse shading where needed, and plan watering around the hottest part of the day.

SteelRoot 3.14 m wide footprints, in real growing language:

4 m / 12.56 m²: two full-size raised beds plus a working path; quarter-allotment scale.
6 m / 18.84 m²: three raised beds, year-round salad and tomato programme.
8 m / 25.12 m²: small-allotment scale; tomatoes, beans, cucumbers and brassicas under one roof. The most-ordered SteelRoot length.
10 m / 31.40 m²: serious-grower volume with overwintering capacity.
12 m / 37.80 m²: commercial-domestic scale; cut-flower microbusiness viable.

If you're between two lengths, take the longer one. The £150 to £200 step is small money compared with rebuilding 18 months in.

Usually no. The 3.14 m line has a ridge height of 2.02 m, comfortably under the 2.5 m UK Permitted Development cap for outbuildings on most domestic plots. Check with your local council if any of these apply: conservation area, listed building, plot under an Article 4 Direction, structure closer than 2 m to a boundary, total outbuildings already covering 50% of your garden.

SteelRoot is classified as a greenhouse rather than a polytunnel, which helps where allotment councils ban polytunnel covers on aesthetic grounds. The plain-language Permitted Development checklist ships in your order pack so you can verify before delivery.

1 to 4 weeks from order for UK mainland, included in the price. Every SteelRoot is made to order. Production typically takes 2 to 3 weeks, plus pallet transit. You receive an "In production" email within 5 working days of order, then an "On its way" email with tracking when the pallet is despatched.

The pallet arrives on a tail-lift truck and is dropped kerbside. SteelRoot pallets are 1.2 × 0.8 to 1.0 × 2.1 m and weigh 65 to 105 kg depending on length. The 2.1 m height is worth checking against any access constraints (low garage doors, narrow side gates) before ordering. You'll receive an SMS the day before with a 4-hour delivery window. Scottish Highlands, the islands and Northern Ireland have surcharges or limited service, calculated at checkout or quoted by email. Full carrier terms on our shipping policy.

You have 14 days from delivery to start a return, unused and in original packaging. We'll arrange the collection through our carrier. SteelRoot pallets are large, so you pay the carrier collection cost, typically £75 to £175 depending on length and your region. We'll quote the exact figure on request before you commit. Full terms on our refund policy.

If the structure has been built and you're stuck on something specific, say a wrong size, a delivery damage that surfaced during the build, or a missing part, talk to us first. Most problems sort out short of a full return.

SteelRoot uses standardised component SKUs that have run unchanged for years. Panels are twin-wall polycarbonate, fasteners and brackets are commodity stainless or zinc-plated hardware, and we keep them documented and coded so we can source replacements rather than re-engineering each time. Parts are stocked for 10 years from purchase.

Replacement parts go through our customer-service team at customer-service rate. SteelRoot is a sub-brand of Waldenhaus, a multi-product UK operator that maintains a living parts catalogue. If you bought a SteelRoot in year 1, you can still buy parts for it in year 10.

Yes. Two options at checkout:

V12 Retail Finance, 0% APR over 12 months: a soft credit check, a decision in minutes, no impact on your credit file unless approved. Typical monthly payment on a 3.14 m SteelRoot runs from £100 (4 m entry) to £162 (12 m flagship).

PayPal Pay Later: split the cost into monthly instalments via your PayPal account, no credit check at our end.

V12 is the UK garden-finance category standard. For commercial buyers or smallholders, longer-term finance (24 to 36 months at 0 to 9.9% APR) is available on request. Book a 15-minute spec call to discuss.

Polytunnels cost less upfront, typically £400 to £1,000 for an equivalent footprint. Over a decade the cost picture rebalances: the polythene cover needs replacement every 5 to 7 years at £200 to £400 plus a weekend of re-trenching, and a torn cover in a winter storm is a documented pattern rather than an edge case. Tensioned-film systems are also banned at many allotment sites and in most conservation areas on aesthetic grounds.

SteelRoot is one capital purchase, with screw-fixed twin-wall polycarbonate that doesn't perish, an architectural arch silhouette that councils accept, and far better thermal retention than a single-skin film. If you love your polytunnel for the growing but the film cycle has worn thin, this is the next step. If you want the lowest cost per m² for a dedicated growing-only space, polytunnels remain a sensible answer.

Entry-tier aluminium greenhouses and SteelRoot serve different requirements. Compare the published frame profile, panel-fixing method, anchoring, glazing options and warranty terms rather than the starting price alone.

SteelRoot uses 40 × 20 mm closed RHS galvanised steel, screw-fixed twin-wall polycarbonate and included ground anchors. The base specification uses 4 mm glazing and 1 m arch spacing; 6 mm and 0.67 m close-arch options are available.