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Bitumen paint or a roof coating

Updated: 21 October 2026

You have a shed roof that weeps at a lap, and amazon.co.uk is offering black bitumen paint beside a roof seal. Bitumen paint vs roof seal is a choice of job. Use a bitumen tin on small, sound felt or metal. Use a roof coating sold to flex or to sit in ponding water. Call a roofer if the deck has failed. Peter F. compared the [Bitumen paint](/hub/flooring-tools-and-accessories/bitumen-paint) listings with three products left out of that set, at 19 October 2026 prices. A purchase through our links can earn a commission at no extra cost to you. Brushing is on [how to apply bitumen paint](/hub/flooring-tools-and-accessories/bitumen-paint/sub/bitumen-paint-how-to-apply), and checks are in the [bitumen paint buying guide](/hub/flooring-tools-and-accessories/bitumen-paint/sub/bitumen-paint-buying-guide).

You have a shed roof that weeps at a lap, and amazon.co.uk is offering black bitumen paint beside a roof seal. Bitumen paint vs roof seal is a choice of job. Use a bitumen tin on small, sound felt or metal.

Our top picks

Bartoline Bartoline Bitcote 5 litre

Best overall

Bartoline Bartoline Bitcote 5 litre
8.7/10about £28.50
View offer
Sika Sika Black Jack 901, 2.5 litre

Best value

Sika Sika Black Jack 901, 2.5 litre
7.3/10about £22.14
View offer
Bird Brand Bird Brand black bitumen paint, 1 litre

Alternative

Bird Brand Bird Brand black bitumen paint, 1 litre
5.3/10about £14.79
View offer
On this page
  1. 1.Three products in one search
  2. 2.When bitumen paint is enough
  3. 3.When a roof coating is the other job
  4. 4.When neither tin is the repair

Three products in one search

Bitumen paint here is a cold-applied black coating in a petroleum solvent, brushed on in two coats. The kept tins run from Bird Brand at £14.79 for 1 litre to Bartoline Bitcote at £28.50 for 5 litres. Sika's UK sheet names existing felt. Thompson's 10 Year Roof Seal, left out of the comparison, was grey, 1 litre, at £17.79. The third family is a liquid membrane. COATERA's silicone listing was 4.7 kg at £65.98 and claimed ponding resistance. Polar Damp Seal, at £38.99, is interior damp paint, not a roof answer.

When bitumen paint is enough

A bitumen tin is enough when the roof is small, the felt or metal is still stuck down, and you are renewing a black maintenance coat. Reviewers describe recoating shed roofs. That is maintenance, not a new roof. Take about 6 m² of sound shed felt. On Sika's porous figure of about 4–6 m² per litre per coat, two coats need roughly 2–3 litres. The 2.5 litre Sika tin is then close to the limit, and the 5 litre Bartoline tin leaves a margin. The film can chalk under UV. That dulling is normal, and it is not, by itself, proof that a lap has failed. If the only problem is sound felt on a shed, the bitumen tin on the main comparison is the product to open.
Bartoline Bartoline Bitcote 5 litre

Testsieger

Bartoline Bartoline Bitcote 5 litre
8.7/10about £28.50
View offer

When a roof coating is the other job

Choose a roof coating when you need movement, a colour that is not black, or a product specified for water that sits. At £17.79 a litre, Thompson's coverage is 2 m², so a garage roof in that seal is several tins. The COATERA silicone listing was a different budget: £65.98 for 4.7 kg, sold with a ponding claim. A coating sold for ponding does not make a roof with no falls a good design. If the roof is GRP, follow the GRP maker. A roof wants an exterior product with a stated surface, a stated cover rate, and a weather window.

When neither tin is the repair

A flat-roof repair guide treats a paint-on sealer as a short repair, with a table of about 1–2 years, and sends a soft deck to a new roof. That lifespan is their table, not a test of Bartoline or Sika. Brushing £28.50 of bitumen into a spongy roof hides the hole until the next wet week. Do not wire-brush a sheet that might be asbestos cement. Sound shed felt or sound sheet metal: a bitumen tin, two coats, no torch. Movement, a non-black colour, or water specified to sit: a roof seal or a liquid membrane whose maker states that job. Soft deck, split structure, or possible asbestos: a roofer.

Common questions

Can I paint bitumen paint on shed felt?
Yes, as a maintenance coat, when the felt is still sound and dry. Sika's UK sheet includes felt. Reviewers describe small shed roofs. Use two coats, and plan on about 4–6 m² per litre per coat if you are using Sika's porous figure. A soft or split roof is not this job. Do not torch felt while the solvent-borne paint is wet.
Is Thompson's roof seal the same thing?
No. The listing left out of the comparison was a 1 litre grey roof seal at £17.79, with 4.5 from 440 reviews, for tiles, slates, and metal. Thompson's say it flexes, is rainproof in 6 hours, and outperforms standard bitumen paint. That comparison is their claim. Their coverage is 2 m² per litre, against Bartoline's 9–13 m² per litre. A similar shelf price does not make them the same tin.
When is a silicone or MS-polymer coating the other job?
When you want a liquid membrane sold for movement or ponding, not a solvent bitumen maintenance coat. The COATERA silicone listing left out of the set was £65.98 for 4.7 kg and claimed ponding resistance. The MS-polymer tub was £68.99 for 5.7 kg. Read that maker's ponding line as their specification. It does not make a roof with no falls acceptable.
Will bitumen paint fix a roof that holds water?
No. Sika's sheet is not a ponding system. The LRWA note says recoating does not remove ponding, and that zero falls are not acceptable on an exposed roof. A bitumen coat on a sound shed is maintenance. A pond on a flat roof is a design and structure problem, not a reason to buy a larger black tin.
Can I torch felt while the paint is wet?
No. Bartoline's flash point is 38–40°C, and the product is a flammable solvent-borne liquid. A torch next to a wet film is a fire risk. Let any bitumen coat dry. If the roof needs new felt bonded with heat, that is a roofing job with the right materials, done when the solvent has gone.
What if the boards underneath are soft?
Stop. A soft deck or a lap that has opened is beyond a tin of paint. Repair guides that quote a short life for a paint-on sealer are describing a holding coat, and their year figures are not a test of these ASINs. A roofer has to see the deck. Another coat hides the spongy board and adds weight. Interior damp paint, such as Polar Damp Seal, is not a substitute on that roof either.

Related pages

Bitumen paint for fence posts

Bitumen paint

Best bitumen paint: the 5 litre and 2.5 litre tins

Bitumen paint buying guide: coverage and tin sizes

How to apply bitumen paint: two coats and a solvent

Sources

Public UK sources and the amazon.co.uk listing lines saved on 19 October 2026. No laboratory test.

  1. Bartoline Bitcote technical data sheet (retrieved 19 October 2026)
  2. Bartoline black bitumen paint (retrieved 19 October 2026)
  3. Sika Black Jack 901 UK product data sheet (retrieved 19 October 2026)
  4. Drinking Water Inspectorate — bitumen products FAQ (retrieved 19 October 2026)
  5. WRAS approvals directory, section 5021 (retrieved 19 October 2026)
  6. HSE CIS27 — solvents (retrieved 19 October 2026)
  7. Bird Brand black bituminous paint (retrieved 19 October 2026)
  8. HSE — creosote ministerial decisions (retrieved 19 October 2026)