Asphalt Roofing in London
Asphalt — poured mastic asphalt — has waterproofed London roofs for more than a century, and a well-laid asphalt roof can still outlast most modern alternatives. Golden Roofing Expert Ltd installs, repairs and renews asphalt roofing and built-up felt flat roofs on houses, blocks of flats, garages and commercial buildings across London.
Asphalt is seamless, has no laps to fail, and handles foot traffic better than almost any other flat roof system. Its weakness is weight and cost, and it must be laid by people who genuinely know the material. That is where a lot of flat roof failures start.
What is mastic asphalt roofing?
Mastic asphalt is a blend of bitumen and limestone aggregate that is heated and poured, then spread by hand to form a continuous seamless layer. Because it is poured rather than rolled out in sheets, there are no joints for water to find. It is typically laid in two or three coats over a separating membrane, with a solar-reflective finish available for exposed roofs.
Asphalt roofing vs built-up felt vs single-ply
Asphalt
Long lifespan, fully seamless, excellent for balconies, walkways and roofs with regular foot traffic. Heavier than other systems, so the structure must be able to carry it.
Built-up felt
Lower cost and lighter. Traditional felt has a shorter lifespan than asphalt, though modern high-performance felts have closed the gap considerably.
Single-ply membrane
Lightest option and fastest to install, with good guarantees. See our flat roofing page for a direct comparison of systems.
When asphalt is the right choice
- Roofs with regular foot traffic — walkways, terraces and balcony decks.
- Complex shapes with many upstands, outlets and change of direction, where seams would otherwise be vulnerable.
- Period properties where a traditional, seamless finish suits the building.
- Garage roofs and extensions that need a hard-wearing, low-maintenance surface.
An asphalt roof renewal in Islington
A maisonette owner in Islington got in touch after two other roofers had “repaired” the same leak on her balcony roof twice over three years, and it kept coming back. Each time, the leak returned along the same line where the asphalt met the parapet wall.
On inspection, the problem was clear. The original asphalt had been patched with a different bitumen product, and the two materials had not bonded. Water was tracking sideways under the patch and emerging well away from the actual defect — which is why the previous repairs never worked.
We stripped the failed section back to sound asphalt, removed the incompatible patch, dressed a proper upstand detail into the parapet and renewed the surface with new asphalt keyed into the existing roof. The balcony was finished with a solar-reflective dressing to keep the surface cooler in summer.
Two winters later the roof has not leaked, and the owner now has a written guarantee covering the work rather than another temporary patch.
Asphalt roof repair or replacement?
Asphalt can often be repaired rather than replaced, provided the surrounding material is still sound and the right products are used. The mistakes we see most often are mismatched materials, patches that do not bond, and repairs that cover a symptom rather than the cause.
If more than roughly a third of the roof area has failed, or the insulation beneath is saturated, replacement usually works out cheaper over the life of the building. We will tell you which side of that line your roof is on — even when the answer is the cheaper repair.
Asphalt roofing FAQs
How long does a mastic asphalt roof last?
A properly installed asphalt roof will typically outlast a felt roof by a considerable margin, and it can be refurbished rather than replaced. Lifespan depends on falls, foot traffic and detailing, which is why our quotation states the guarantee rather than a rule-of-thumb number.
Can asphalt be laid over an existing roof?
Sometimes, provided the deck is structurally sound and the existing layers are suitable. Because asphalt is heavy, this decision always follows a survey.
Is asphalt suitable for a domestic house roof?
Yes. Asphalt is common on bay roofs, balconies, extensions and garages, and it suits properties where a seamless finish is important.
Do you repair roofs other firms have patched?
Often. Our roof leak repair service specialises in finding the real cause of recurring leaks.
Get an asphalt roofing quote in London
Tell us about your roof and we will arrange a survey. Asphalt and built-up felt sit alongside the rest of our London roofing services, including guttering and fascia and soffit work. Get in touch through our contact page.
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