The best Vapour barriers, compared.
Top pick: B2C yellow 0.2 mm, 20 m² Best value: Just The Job GVC2, 2.5 m x 5 m – Lowest shelf price on a stated 125 micron cut, if you measure it on arrival. Updated October 2026.
It can help airtightness if the laps and holes are sealed. People buy it for garden rooms, stud walls and insulated roofs, mostly as a 500 gauge (125 micron) green sheet. Cites 125 micron on the warm side for framed work. A damp-proof membrane under a slab is a different sheet: Approved Document C paragraph 4.8 asks for polyethylene of at least 300 µm (1200 gauge). Compare stated thickness, width, coverage, whether EN 13984 is named, and whether the title agrees with the coverage field. Gauge, width and coverage are set out in the [vapour barrier buying guide](/hub/flooring-tools-and-accessories/vapour-barrier/sub/vapour-barrier-buying-guide). A vapour barrier, as UK shoppers search for it, is usually a polythene vapour control layer.
It can help airtightness if the laps and holes are sealed. People buy it for garden rooms, stud walls and insulated roofs, mostly as a 500 gauge (125 micron) green sheet.
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Personal buying guide
Question 1 of 2
What are you lining?
The B2C yellow sheet is listed at £19.79 as polyethylene, 0.2 mm with a ±30% tolerance, made in Poland. The coverage field says 20 square metres, which matches the 2 m x 10 m phrase in the title and not the 2 m x 50 m phrase. It is 5.0 from two ratings. The only United Kingdom text says thick and robust. There is no EN 13984 line. It is a short yellow film with a size clash, not a 500 gauge roll and not a confirmed 100 m² sheet.
Pros
Cons
Best for: You want a yellow polyethylene sheet whose coverage field says 20 m².
Less suitable: You need a 50 m roll, a 500 gauge label, or a named British Standard.
Specifications
Common questions
How big is this yellow sheet?
The coverage field says 20 square metres. The title says 2 m x 50 m and, in brackets, yellow 2 m x 10 m. Two metres by 10 metres is 20 square metres. Two metres by 50 metres is not.
Does the listing say it can go under laminate?
A listing question asks that. The bullets name concrete floors and screeds, walls, roofs, ceilings and foundations. They do not name laminate.
What standard is named?
The bullets say Attested Foil T30 and professional building standards. No BS or EN number is in the saved listing. The rating is 5.0 from 2, with one written review.
The ndcpolipak roll is listed at £63.69 as a 500 gauge, 125MU green polythene vapour control layer, 2.7 m x 50 m. The bullets say CE marked to EN 13984 and name Damplas for walls, roofs and floors. It is 4.6 from 97 amazon.co.uk reviews. Across 13 United Kingdom texts, buyers often call it strong and use it in garden rooms. One verified review says the width was 2.45 m, and another reports holes at the folds. It is the top pick in this set as the only full roll that names both the gauge and EN 13984, with the largest review sample, not as a measured sheet.
Pros
Cons
Best for: You want a full 500 gauge roll and you will check the width on delivery.
Less suitable: You need a 1200 gauge damp-proof membrane under a slab, or a width you can take from the title alone.
Specifications
Common questions
What thickness does this roll state?
The title says 500 gauge and 125MU, green tint, 2.7 m x 50 m. The bullets say it is CE marked to EN 13984.
Where does the listing say it can be used?
The bullets say wall, roof and floor construction, to limit moisture and to improve airtightness. They use the name Damplas. They do not mention laminate.
Did reviewers get the stated width?
One verified UK review says the sheet was 2.45 m wide, not 2.7 m. Another says it was not as big as advertised and had holes where it had been folded.
The Just The Job GVC2 cut is listed at £12.60, the lowest shelf price in this set, as a green 125 micron vapour check with 2.5 m width and 5 metres in the title. It is 4.5 from 17 reviews. Seven United Kingdom texts call it strong or thick. Two say it arrived folded rather than on a roll, and the dimension line can be read as 10 m x 2.5 m. One reviewer describes a 2.5 m x 20 m sheet, which is not this title length. It is the best value only as a small stated 125 micron cut, not as a confirmed 5 m roll.
Pros
Cons
Best for: You want the lowest price on a stated 125 micron sheet and you will measure it on arrival.
Less suitable: You need a full 50 m roll, a named standard, or a sheet that the listing shows on a roll.
Specifications
Common questions
What size is this cut?
The title says 2.5 m wide and 5 metres, with other lengths offered. The dimension line is 1000 x 250 x 0.01 cm, which does not match a 5 m length.
Does the listing name a standard?
No. The bullets say 125 micron and 500-gauge for walls, floors and roofs. They do not name EN 13984. The material field says 5 Metres.
Does it arrive on a roll?
Two United Kingdom reviews say it was folded, not on a roll. One of those still calls it good.
The Just The Job GVC4 cut is listed at £15.69 as a green 125 micron vapour check, 4 m wide and 5 metres in the title. The bullets match the narrower GVC2 cut: 500-gauge wording, timber frame, and a green tint you can see studs through. It is 4.5 from 10 reviews, with only two short United Kingdom texts in the saved listing and no complaint in those two. The dimension line does not confirm 5 metres. It is the wider short cut in this set, not a second full roll.
Pros
Cons
Best for: You want a stated 4 m width on a short 125 micron cut and you will check the length.
Less suitable: You need a 50 m roll, a named standard, or more than two written reviews.
Specifications
Common questions
How wide is this sheet?
The title says 4 m width and 5 metres. The dimension line is 1 x 400 x 0.01 cm, so the 4 m width appears there and the 5 m length does not.
Can the listing be used on floors?
The bullets say walls, floors and roofs, and timber-frame, underfloor and roof uses. They do not name laminate or a 1200 gauge damp-proof membrane.
What do the written reviews say?
Two United Kingdom texts say it does the job. One title mentions building regulations. The body does not cite a regulation. The rating line is 4.5 from 10.
The B2C foil sheet is listed at £42.25 as an aluminium and kraft vapour barrier, 1.25 m by 24 m, 30 m², 3.6 kg, made in Poland. The bullets place it on sauna walls and ceilings and state a water-vapour resistance of 2748 m without a test method. There is no review line in the saved listing and no EN number. It is a sauna facing in this set, not a 500 gauge polythene roll and not a damp-proof membrane.
Pros
Cons
Best for: You are lining a sauna and the design asks for a foil and kraft sheet of about 30 m².
Less suitable: You want green 500 gauge polythene, a reviewed roll, or a below-slab damp-proof membrane.
Specifications
Common questions
What is this sheet made of?
The spec table says aluminium and kraft paper. The bullets describe a foil and kraft laminate for sauna walls and ceilings, 1.25 m x 24 m, 30 m², basis weight 120 g/m².
Does the listing name steam rooms?
Yes. Recommended uses include sauna walls and ceilings, steam rooms, timber frame, moisture-barrier installations and thermal insulation. No fire class is given, although a listing question asks about fire resistance.
Are there amazon.co.uk reviews?
The saved listing has no customer-review line and no review text. The vapour-resistance figure 2748 m is in the bullets without a test method.
Five amazon.co.uk listings were scored from the pages kept for this set. Weights are Amazon evidence 30, listing fit 40 and value 30. This is not a lab test, and naming EN 13984 is the seller’s claim, not a building-control sign-off. The top pick is the ndcpolipak 500 gauge roll. The best value is the Just The Job GVC2 cut at the lowest shelf price.
Amazon evidence
30%Stars and the review count on the amazon.co.uk line. The score drops when the sample is two ratings, when written texts are missing, or when UK texts report a short width or holes at the folds.
Listing fit
40%A stated thickness, a size that agrees with the coverage field, a named use, and whether EN 13984 appears. A title that also prints a second, different size scores lower.
Value
30%Shelf price on 19 October 2026 against the area the listing actually supports. A short cut can score on price. A size clash cannot be turned into a firm price per square metre.
Match the sheet to the moisture before you compare the shelf price. Room vapour on the warm side of a frame, ground moisture under a slab, and a sauna facing are different buys. The five prices below are the amazon.co.uk lines in this comparison, from about £12.60 to about £63.69. A price per square metre is given only where the title dimensions can both hold.
A vapour barrier, as UK shoppers search for it, is usually a polythene vapour control layer. It slows room moisture moving into a wall, roof or timber floor, and it can help airtightness if the laps and holes are sealed. People buy it for garden rooms, stud walls and insulated roofs, mostly as a 500 gauge (125 micron) green sheet. LABC Warranty cites 125 micron on the warm side of frames as one accepted form. A damp-proof membrane under a slab is a different sheet.
125 micron polythene is a warm-side vapour control layer. Approved Document C paragraph 4.8 asks for polyethylene below a ground-supported slab of at least 300 µm (1200 gauge), joints sealed. A floors bullet does not change the gauge. NHBC floor laps and NHBC roof laps are different lengths.
If the title, the coverage field and the dimension line disagree, keep both figures. The yellow sheet’s coverage field says 20 m², which matches 2 m x 10 m. The same title also says 2 m x 50 m. Do not price a square metre from the larger figure alone.
A 5.0 from two ratings is a thinner sample than a 4.6 from 97 that includes a width complaint and holes at the folds. The foil listing has no review line. Seam tape and window felt are separate products. If the sheet is the air barrier, lap it and tape it before you board.
Name the moisture before the price. Room vapour in a frame needs a vapour control layer on the warm side. Ground moisture under concrete needs a damp-proof membrane. A floors bullet does not turn 125 micron polythene into the slab membrane. Approved Document C paragraph 4.8 asks for polyethylene below a ground-supported slab of at least 300 µm (1200 gauge), joints sealed. None of these five listings is that sheet. Read thickness next.
Check width and length against coverage. If the title, the coverage field and the dimension line disagree, keep both figures. The ndcpolipak title says 2.7 m x 50 m. One verified UK review says the sheet was 2.45 m wide, so a price per square metre depends on the width you receive. Just The Job GVC2 is titled 2.5 m x 5 m at about £12.60, while the dimension line is 1000 x 250 x 0.01 cm. GVC4 is titled 4 m x 5 m at about £15.69, and the dimension line does not show 5 m.
Three typical situations, each with a recommendation from this comparison.
You can reach the warm side of a frame and you want a taped 500 gauge sheet. The ndcpolipak roll is about £63.69, titled 2.7 m x 50 m, with EN 13984 in the bullets and 4.6 from 97 reviews. One UK review says the width was 2.45 m. Measure it on delivery. It is a warm-side vapour control layer.
A floating floor on concrete still needs its own damp-proof approach. Underlay film and a 500 gauge sheet are warm-side or packaging films, not the 1200 gauge polyethylene under a slab in Approved Document C. If you also need a small 125 micron cut and you will measure it, the Just The Job GVC2 is about £12.60.
You are lining sauna walls or a steam room and the design asks for foil and kraft. The B2C sheet is about £42.25, 1.25 m x 24 m, 30 m². The bullets state a vapour resistance of 2748 m with no test method, and the saved listing has no review line. High-humidity rooms need a design.
The top pick is the ndcpolipak 500 gauge roll at about £63.69. It is the only full roll in this set that names both 500 gauge and EN 13984, and it has the largest review sample, 4.6 from 97. One UK review says the sheet was 2.45 m wide, and another reports holes at the folds, so check the roll on delivery. The best value is the Just The Job GVC2 cut at about £12.60, a stated 125 micron sheet at the lowest shelf price, with a dimension line that does not match the 5 m title. The foil and kraft sheet is a sauna facing. None of these five is a 1200 gauge damp-proof membrane.
Just The Job GVC2, 2.5 m x 5 m
Lowest shelf price on a stated 125 micron cut, if you measure it on arrival.
Editorial
Peter F. is the editor for DIY & tools at productscompared.co.uk. Comparisons in this category are checked against amazon.co.uk listings, review evidence and public UK sources.
Guides on what to look for, how to use a product, and common mistakes.
Public UK sources used for this comparison. Listing prices, stars and review counts are the amazon.co.uk lines kept with these five products. Shelf date 19 October 2026.
This page contains affiliate links to amazon.co.uk with the tag pcuk26-21. If you buy through them, we may earn a commission at no extra cost to you. Prices, stars and review counts are the UK listing lines for this comparison. We did not run a lab test.
