Roof coatings and sealants: what we honestly think
Roof coating and sealant products are marketed heavily on claims of waterproofing, extending roof life and reducing future cleaning. Some homeowners ask us whether we apply them, or whether they are worth having done after a clean. We think this deserves a genuinely balanced answer rather than either a blanket endorsement or a blanket dismissal.
We do not apply roof coatings or sealants ourselves, and this page explains our reasoning honestly, without exaggerating risks that do not apply to every product, and without implying a certainty we do not have about every formulation on the market.
What coating products typically claim
Roof coating systems are generally marketed as extending the life of a tile roof, improving weatherproofing, restoring colour to faded tiles, and reducing future organic growth by creating a smoother, less porous surface. Some of these claims may hold true for specific products applied correctly to suitable roofs — we are not in a position to test or verify every product on the market.
Where our caution comes from
- A coating changes the roof's original breathability and appearance, which is a bigger intervention than cleaning and treatment.
- Coating performance depends heavily on correct surface preparation and application — poor prep is a common cause of premature coating failure and can trap moisture beneath the film.
- Coatings are typically a long-term commitment; removing a failed or peeling coating is more involved than dealing with the original moss would have been.
- We have not seen independent, long-term evidence that convinces us to recommend coating as standard practice, as distinct from cleaning and biocide treatment.
Our position, plainly
We focus on hand cleaning and biocide treatment because we can stand behind exactly what that process does to a roof: removes growth, treats what remains, and leaves the original tile surface intact and breathable. We are not saying coatings never have a place — only that we are not in a position to apply or recommend them with the same confidence, and we would rather tell you that plainly than sell you something we are unsure about.
Our own photographs
Images from Sky Scrapers Ltd work showing the methods described on this page.
Where this applies locally
Towns where this comes up most often on our patch:
Questions we get asked
Do you apply roof coatings or sealants?
No. We focus on hand cleaning and biocide treatment, which we can stand behind based on how it actually affects the tile surface.
Are all roof coating products the same?
No — formulations and application methods vary considerably between products and installers, which is part of why we are cautious about making a blanket recommendation either way.
If my roof already has a coating, can you still clean it?
We would assess it on its own terms — a coated roof behaves differently to an untreated one, and we would look at its actual condition before advising on the right approach.
Does a coated roof still need regular cleaning?
Coated roofs can still collect organic growth and debris over time, particularly in shaded or sheltered areas, so ongoing maintenance is still generally relevant.
Ask us for an honest opinion
If you are weighing up a coating quote against a clean-and-treat approach, send us the details and we will give you a straight view.
Sky Scrapers Ltd · info@sky-scrapers.co.uk
Summary
Roof coatings claim significant benefits, but performance depends heavily on preparation and product quality, and failure can be more costly than the original moss problem. We focus on cleaning and treatment, which we can stand behind directly.