Polytunnel polythene thickness: a practical buying guide
Updated: October 2026
You are looking at a clear sheet for a cold frame, greenhouse or tunnel, but the listing calls it “heavy duty” without telling you what heavy duty means. The useful number is polytunnel polythene thickness, stated in microns or mil, followed by a credible UV life and dimensions that agree throughout the listing. Our [greenhouse film comparison](/hub/raised-beds-greenhouses-and-compost/greenhouse-film) shows eight amazon.co.uk rows; this guide explains how to read those rows before you order. The short rule is to buy the gauge and UV term you can actually see, then measure the delivered sheet before building around it.
You are looking at a clear sheet for a cold frame, greenhouse or tunnel, but the listing calls it “heavy duty” without telling you what heavy duty means.
You are looking at a clear sheet for a cold frame, greenhouse or tunnel, but the listing calls it “heavy duty” without telling you what heavy duty means. The useful number is polytunnel polythene thickness, stated in microns or mil, followed by a credible UV life and dimensions that agree throughout the listing. Our greenhouse film comparison shows eight amazon.co.uk rows; this guide explains how to read those rows before you order. The short rule is to buy the gauge and UV term you can actually see, then measure the delivered sheet before building around it.
Our top picks
| Badge | Product | Stated thickness | UV claim | Stated size | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  GSHUR GSHUR 2 m × 2 m polythene sheet | – | No | 2 m × 2 m | 7.8 | about £7.99 | View offer |
 AGGAFA AGGAFA 150 µm greenhouse film, 2 m × 3 m | 150 µm (6 mil) | Over 4 years | 2 m × 3 m | 8.6 | about £12.99 | View offer | |
 Pumtus Pumtus 6 mil greenhouse film, 3 m × 8 m | 6 mil | No year | 3 m × 8 m | 6.8 | about £16.14 | View offer |
On this page
What the UK thickness bands actually mean
Specialist UK suppliers describe horticultural film with a thickness and a service promise, not just an adjective. Premier Polytunnels lists 120 micron cloche film with a two-year warranty, 150 micron film with a four-year UV warranty, and 180 micron film with a five-year warranty. Northern Polytunnels specifies its clear film at 180 micron, with 92% light transmission and a five-season UK UV warranty.
In this comparison, AGGAFA B0D8HN9N8Z is the only row that explicitly states 150 µm, also written as 6 mil. GSHUR B0D4723JDD gives no micron figure at all. That does not prove GSHUR is unusable, but it prevents a like-for-like thickness comparison. The best greenhouse film picks cover the selection within this particular set.
Mil, gauge and the weight cross-check
Microns and mil are different units for the same physical idea. Six mil is about 0.15 mm, or 150 microns; it does not mean 6 mm. Dividing traditional gauge by four gives an approximate micron figure, so 600 gauge corresponds to about 150 micron and 720 gauge to about 180 micron.
Weight can provide a rough plausibility check. Treat that as a rule of thumb for spotting a large contradiction, not certifying a film. AGGAFA’s stated 2 m × 3 m sheet is six square metres. At 150 microns, a simple density calculation lands in the same broad region as its listed 840 g. RUCUDIM B0D2R537KH is different: a bullet places 0.3 mm, 2 m × 3 m and about 400 g together, while the details say 380 g. Those figures do not sit comfortably together.
UV wording is not a year count
“UV-resistant” and “UV-stabilised” tell you that a seller is making a treatment claim. They do not tell you how long the seller stands behind the film in British conditions. A useful listing ties the claim to a number of years or seasons and sets out the warranty terms.
AGGAFA includes a line about more than four years in a bullet. That makes it more specific than a bare UV word, but it remains a bullet rather than a separate warranty field. CHESTAF says UV-stabilised without a year, Teenfa says UV-resistant without a year, and GSHUR makes no UV claim. Pumtus also uses UV language but gives no year count.
When the dimensions disagree
Read the title, selected size, dimensions line, model or part number, weight and included-components line as a set. If two of them describe different objects, do not quietly choose the larger or more convenient one.
Teenfa B0FQN4X8ZG says 2 m × 3 m in the title while its dimensions line reads 500 × 270 × 0.1 cm. JEUIHAU B0FB2YGVGR has a 2 m × 15 m bullet against dimensions of 1500 × 1500 × 200 cm. AGGAFA has a subtler mismatch: the size field says 2 m × 3 m while the model number contains 4M×5M.
Applying the test to your job
Start with the frame, not the product title. Measure the width over the hoops rather than the width across the ground, add the required fixing allowance, and allow for the ends. If it is a walking tunnel, follow the measuring approach in the polytunnel cover guide before comparing sheet areas. A 2 m square can cover a cold frame yet be entirely wrong for a tunnel.
Then apply four checks in order: stated size, stated thickness, UV term and evidence from the exact listing. Reject any row whose confirmed dimensions cannot cover the frame. Prefer an explicit micron or mil figure over “heavy duty”, and a named year or season term over generic UV wording.
Common questions
What thickness should a polytunnel cover be?
UK specialist examples commonly sit at 150, 180 or 200 microns. Published terms in the research range from four UV years for named 150 micron film to five seasons at 180 micron and seven years at 200 micron. Those terms belong to the named products; thickness alone does not guarantee the same life.
Is 6 mil the same as 150 micron?
It is approximately the same: 6 mil is about 0.152 mm, or 152 microns, and sellers commonly round that to 150 µm. Do not confuse mil with millimetres. Six millimetres would be forty times thicker than 150 micron film.
Is “UV-resistant” a warranty?
No. It is a product claim without a duration unless the listing also gives a year or season term and warranty conditions. A published four-year UV warranty is more informative than “UV-resistant”, but it still applies only to the product and conditions stated by that supplier.
Does a heavier sheet automatically last longer?
No. Weight can help check whether size and thickness are plausible, but service life also depends on UV stabilisation, manufacture, fitting, abrasion and exposure. A thick cover fitted over sharp edges or left flapping can fail early.
Do these amazon sheets meet BS EN 13206?
None of the eight listings in this set states a BS EN 13206 class. A greenhouse title, stated micron figure or UV bullet is not evidence of compliance. Ask for documentation if the standard matters to your purchase.
Related pages
Sources
Public UK and manufacturer sources from the research digest, used for this page in October 2026.
- BSI — BS EN 13206:2025 greenhouse and tunnel films (retrieved 17.10.2026)
- Northern Polytunnels — Durathermic clear polythene (retrieved 17.10.2026)
- Premier Polytunnels — polythene films (retrieved 17.10.2026)
- Northern Polytunnels — covering a polytunnel (retrieved 17.10.2026)
- RHS — choosing a greenhouse (retrieved 17.10.2026)
- Consumer Rights Act 2015, section 11 (retrieved 17.10.2026)
- GOV.UK — waste duty of care code of practice (retrieved 17.10.2026)
- SEPA — agricultural waste (retrieved 17.10.2026)