Protective roof coating to extend the life of an existing roof
Roof Coating
Roof coating is a protective liquid membrane applied to an existing, structurally sound roof covering after cleaning and biocide treatment, intended to seal, waterproof and extend the working life of tiles, slates or a flat roof membrane without the cost of full replacement.
Definition
What Roof Coating covers
A roof coating system typically involves cleaning the roof, treating it with a biocide to kill moss and algae, then applying a liquid coating, commonly acrylic or similar, that seals porous or ageing tiles and provides a degree of additional waterproofing. It's most suited to an ageing but structurally sound roof where a full re-roof isn't yet justified, and is not a substitute for repairing an already-failing covering.
Suitable for
- Ageing tile or slate roofs that are structurally sound but showing porosity or surface wear
- Flat roofs where recoating extends life ahead of full replacement
- Improving appearance and weather resistance without the cost of a full re-roof
- Roofs recently cleaned and ready for a protective finish
Not suitable for
- Roofs with existing leaks, failed flashings or structural defects — coating doesn't fix these, and they should be repaired first
- Roofs already at the end of their structural life, where coating would delay a necessary re-roof rather than genuinely extend it
Process
How the work is carried out
- 01
Survey
Assessing the roof's structural condition to confirm coating is appropriate rather than repair or replacement.
- 02
Clean and treat
Removing moss, algae and dirt, then applying a biocide treatment.
- 03
Coating
Applying the protective coating system in the recommended number of coats.
- 04
Completion
Final inspection and guarantee documentation for the coating product used.
Typical timescale
A standard semi-detached roof is typically coated within one to two days including cleaning, weather permitting.
Cost guidance
Roof coating typically costs £20–£45 per m² in our area, with roof pitch, access and the number of coats specified pushing the price toward the top of that range. We provide an itemised quotation after a site visit rather than a fixed headline price.
Limitations and exclusions
- Coating is only carried out on roofs assessed as structurally sound — we'll advise against it and recommend repair or re-roofing instead if that's not the case
- Underlying leaks, flashing failures or damaged tiles are not fixed by coating and are quoted separately if found
- Coating product warranties vary by manufacturer and are provided on completion
Areas we cover
Roof Coating across Sussex, Surrey, Kent and South London
Local property styles, planning authorities and neighbourhood coverage for roof coating in each town we work in.
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FAQs
Roof Coating FAQs
Will a roof coating stop my roof leaking?
Not if the leak is caused by a failed flashing, cracked tile or other specific defect — coating seals and waterproofs a sound but ageing covering, it doesn't fix an active fault. We assess this at survey and recommend repair first where that's the actual cause.
How long does a roof coating last?
It varies by product and roof exposure, but a well-applied coating typically extends a roof's serviceable life by a number of years before recoating or eventual replacement is needed. We can advise on the expected lifespan of the specific product recommended for your roof.
Is coating cheaper than a full re-roof?
Yes, considerably, which is why it's a sensible option for a structurally sound roof that's simply ageing or porous. It's not a substitute for a re-roof once the covering itself has genuinely reached the end of its structural life, and we'll say so honestly if that's the case.
Discuss your roof coating project
Tell us about the property and what you have in mind, and we'll arrange a site visit.
Last reviewed 2026-07-28.