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Aluminium foil tape for insulation joints

Updated: 23 October 2026

You are closing a gap in foil-faced PIR, a heating duct, pipe lagging, or the jacket around a flexible liner. Aluminium foil tape for insulation joints is the right family. It still does not make the gas-tight joint in the flue pipe. This page stays on the facing, the seam and the jacket. The twelve cards are the [flue tape comparison](/hub/diy-supplies/flue-tape). The listings, UK review notes, and public notes from BuildWiz, a Celotex BBA certificate, National Flues and Glowing Embers were used. Shelf prices are from 21 October 2026. A qualifying purchase can earn a commission at no extra cost to you.

You are closing a gap in foil-faced PIR, a heating duct, pipe lagging, or the jacket around a flexible liner. Aluminium foil tape for insulation joints is the right family.

Our top picks

BOMEI PACK BOMEI PACK aluminium foil tape, 3 × 50 mm × 50 m

Best overall

BOMEI PACK BOMEI PACK aluminium foil tape, 3 × 50 mm × 50 m
9.1/10about £19.99
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BOMEI PACK BOMEI PACK aluminium foil tape 100 mm × 50 m

Alternative

BOMEI PACK BOMEI PACK aluminium foil tape 100 mm × 50 m
8.6/10about £17.99
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Gladiator Gladiator aluminium tape 50 mm × 10 m

Rank 3

Gladiator Gladiator aluminium tape 50 mm × 10 m
9.3/10about £5.95
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On this page
  1. 1.Board joints and the width
  2. 2.Ducts, lagging and radiator foil
  3. 3.When the length fields disagree
  4. 4.The jacket around a liner

Board joints and the width

Foil-faced PIR is taped so the facing stays continuous. BuildWiz uses about 50 mm for a patch or a penetration and about 75 mm or 100 mm for a long board joint, because 50 mm leaves a narrow land if the boards are not butted. The BBA certificate for Celotex pitched roofing allows foil tape on small areas of damaged facing, and says a flue pipe through the insulation should be sleeved. Tape on the board is not that sleeve. Agreed long rolls at the captured prices are the 75 mm by 50 m BOMEI roll at £15.99, the 100 mm by 50 m roll at £17.99, Ealyder at 75 mm by 59.4 m and £14.99, and the 50 mm three-pack at £19.99, about 150 m. Width and price per metre stay on the flue tape buying guide.

Ducts, lagging and radiator foil

The same soft foil is what the reviews used on heating ducts, pipe lagging and radiator foil. Gladiator's UK reviews, inside a 50-review cap, describe ducting, boards and an air-conditioner hose that cloth tape had left. ArmaKit's notes describe loft boards and radiator foil on 48 mm by 10 m, stated 50 micron, with no printed temperature. The 75 mm BOMEI roll states −20 °C to 180 °C and no micron. Gladiator is 30 micron, and one hot exhaust box let it go after three or four days. Waterproof on the listing is not a reason to skip the duct's own joint. Ealyder is 75 mm by 59.4 m and prints no degrees.
BOMEI PACK BOMEI PACK aluminium foil tape, 3 × 50 mm × 50 m

Testsieger

BOMEI PACK BOMEI PACK aluminium foil tape, 3 × 50 mm × 50 m
9.1/10about £19.99
View offer

When the length fields disagree

If the length fields disagree, do not plan the loft around them. The 300 mm BOMEI row mixes 55 yards, 1,650.92 m and a unit count of 1.0 metre at £35.99. There is no fair price per metre, and no UK review text was saved. If the crack is wider than the land of the tape, widen the tape or close the boards. A second skinny strip beside the first leaves a ridge.

The jacket around a liner

National Flues sells a wrap kit with 50 mm aluminium tape for the blanket joints and metal bands about every 500 mm. Glowing Embers is clear that the foil is not the liner joint. A 550 °C figure on a blanket does not move onto Gladiator's 120 °C, onto BOMEI's 180 °C, or onto a roll that prints no degrees. The bands hold the blanket. The tape closes the foil overlap. The inner joint stays the manufacturer's joint. You can tape the jacket, or PIR around a sleeved pipe, with the three-pack or a short Gladiator patch. You do not tape the flue pipe, the stove, or a plastic condensing flue. Installing the liner is a HETAS or building-control job. If soot, spillage, or a carbon monoxide alarm is why you opened the loft, leave the tape and use boiler flue tape.

Common questions

Do you need foil tape on PIR board joints?
Foil-faced boards are taped so the facing stays continuous. Celotex names a foil insulation tape for that joint, and the BBA sheet allows foil tape on small areas of damaged facing. You need a clean, dry board and a width that lands properly each side of the crack. You do not need a flue-rated product, and none of these ASINs carries a chimney class. A flue through the same insulation is sleeved, which is a different detail.
Can the same tape seal a heating duct?
The UK reviews use these rolls on ducting, an air-conditioner hose and a vent pipe, after the duct is already connected. Tape covers the seam. It does not replace the clip or the coupling. Waterproof on the listing is not a pressure test. Cloth duct tape is the one to avoid on a warm joint, because the reviews describe it melting off where foil stayed, until a hot exhaust box proved too much for thin foil.
Where does foil tape go on a flexible liner?
On the insulation jacket, not on the liner joint. Merchant kits use about 50 mm aluminium tape on the overlap of the wrap, with bands about every 500 mm holding the blanket. Glowing Embers makes the same split. The inner joint stays as the liner manufacturer specifies, fitted by a HETAS installer or through building control. This page does not set out a liner installation.
Does a liner-wrap's 550 °C apply to the tape?
No. The blanket's temperature is the blanket's. Gladiator states 120 °C. BOMEI states −20 °C to 180 °C with no standard. Ealyder and ArmaKit state no degrees. Copying 550 °C onto the tape because it was in the same kit is how a jacket repair gets described as a chimney rating. The tape closes foil. The wrap is the insulation. They are not one number.
When does this job become a Gas Safe or HETAS job?
It becomes Gas Safe when you are on a gas appliance or a gas flue, including a flue hidden in a void. It becomes HETAS or building control when you are on a solid-fuel stove or a liner joint. Taping PIR in the loft, a heating duct, radiator foil, or the outside of a liner jacket can stay a foil job. Soot, spillage, a smell of gas, or a carbon monoxide alarm means you stop and leave the roll where it is.

Related pages

Best flue tape

How to apply aluminium foil tape

Flue tape

Boiler flue tape: a gas flue is not a DIY tape job

Flue tape buying guide: width, length and heat limit

Sources

Public UK sources and the amazon.co.uk listings compared on this page. Listings captured 21 October 2026. Updated 22.10.2026.

  1. Gas Safe Register: home improvements (retrieved 22.10.2026)
  2. Gas Safety (Installation and Use) Regulations 1998, regulation 27 (retrieved 22.10.2026)
  3. HSE: flues in voids (retrieved 22.10.2026)
  4. Approved Document J (2022 PDF) (retrieved 22.10.2026)
  5. Advance Tapes AT500 (retrieved 22.10.2026)
  6. PAR Group aluminium foil tape (retrieved 22.10.2026)
  7. HETAS consumer FAQ (retrieved 22.10.2026)
  8. NHS: carbon monoxide poisoning (retrieved 22.10.2026)