The best Mildew treatments, compared.
Top pick: Mold Armor FG516 mould blocker 946 ml – Only listing at 4.2 with at least 500 reviews. The surface field is fabric, not painted walls. Best value: Professional Strength bleach-free mould remover 500 ml – Lowest price per litre, about £19.98, from the £9.99 listing. Not the deepest review sample. Updated October 2026.
A mildew treatment is a liquid you put on a hard surface to kill or suppress mould or mildew before you decorate, or to slow regrowth after a clean. It is not a decorative emulsion and not a garden spray. UK shoppers use one on a bathroom ceiling, a window reveal, tiles, or a patch of painted wall. The bottle is then a remover, a leave-on preventer, or a fabric blocker. You tell a suitable bottle by the surface it names. Walls, ceilings, tile, and masonry are the decorating job. Furniture and fabric is a different job. A remover is for growth you can see. A preventer is left on after a clean. A blocker title does not mean thick growth vanishes in one spray. Trade washes often print an HSE number. A 500 ml spray with no coverage figure is a patch bottle. GOV.UK says use a mould and mildew product rather than bleach, wear a mask, gloves, and goggles, and dry the surface. How to match the bottle to the surface is in the [mildew treatment buying guide](/hub/paints-and-varnishes/mildew-treatment/sub/mildew-treatment-buying-guide).
A mildew treatment is a liquid you put on a hard surface to kill or suppress mould or mildew before you decorate, or to slow regrowth after a clean. It is not a decorative emulsion and not a garden spray.
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Personal buying guide
Question 1 of 2
What are you treating?
Mold Armor FG516 is a 946 ml trigger spray at £25.47 on amazon.co.uk, about £26.92 per litre, with 4.2 from 2,876 reviews. The listing names furniture and upholstery, and the surface field is fabric. It is chlorine free and the special feature is antimicrobial. In the first 50 review texts, one is from the United Kingdom: a bathroom ceiling showed no instant change. United States texts mention outdoor fabric, grout, car paint, leaking bottles, broken caps, and one warning about harsh fumes and skin contact. It is the top pick here only because it is the sole listing at 4.2 with at least 500 reviews. It is the wrong bottle if you need a wall wash whose listing names painted rooms.
Pros
Cons
Best for: Someone who wants the largest review count in this set and is treating fabric or upholstery, which is what the listing names.
Less suitable: A painted bathroom wall, if you need the listing itself to name walls, or if you need United Kingdom review texts.
Specifications
Common questions
What surface does the listing recommend?
Fabric. Specific uses are furniture and upholstery. The only UK review in the raw sample used it on a bathroom ceiling and saw no instant change.
Are the 2,876 reviews all from the United Kingdom?
The listing count is 2,876 at 4.2 out of 5. Of the first 50 texts in the saved listing, one is from the United Kingdom and 47 are from the United States.
Does the listing say it is chlorine free?
Yes. The material field says chlorine free, and the special feature is antimicrobial. The bottle is 946 ml at £25.47.
Professional Strength is a bleach-free 500 ml spray at £9.99 on amazon.co.uk, about £19.98 per litre, with 4.2 from 15 reviews. The title names bathrooms, kitchens, and walls. Bullets add ceilings, tiles, masonry, wood, and interior and exterior use. Six UK reviews are in the saved listing. Several say it did what the bottle claimed. One says there was no smell, calls it pet safe, and says to wash mould down first. One title says not to waste your money, while that same review says window mould seemed to go. No review states how many months it lasted. The listing says contains liquid contents: no, which conflicts with a 500 ml spray. It is the best value here on price per litre. It is a thin evidence base if you need hundreds of reviews.
Pros
Cons
Best for: A small bathroom, kitchen, or wall patch when you want the lowest price per litre and a bleach-free title.
Less suitable: A whole elevation, or a buyer who wants an HSE number printed on the amazon.co.uk text.
Specifications
Common questions
Does the listing say this spray is bleach-free?
Yes. The title and the material field say bleach free. It is a 500 ml spray, and the title names bathrooms, kitchens, and walls.
What do the UK reviews say about smell and pets?
One of six UK reviews says there was no smell and calls it pet safe, after washing mould down first. The listing does not include a toxicity study.
How many reviews sit behind the score?
The listing says 4.2 out of 5 from 15 reviews. The saved listing contains six United Kingdom texts.
Strewth is a 500 ml mould preventer at £14.99 on amazon.co.uk, about £29.98 per litre, with 3.8 from 4 reviews. The listing names tile, grout, walls, and seals, and the bullets say spray it on and leave it, with no wipe. The saved listing has one of the four reviews. That UK review says a wipe was needed to remove mould, that there was no sticky film once dry, and that mould returned within two weeks while humidity stayed in the high 70s to 80s percent. After dehumidifiers, the same reviewer reported about two months without a widespread return. It is the highest price per litre here, and the evidence is a single written review.
Pros
Cons
Best for: Tile, grout, or a wall where you want a leave-on preventer and you will also deal with humidity.
Less suitable: Someone who needs one application to last through a wet bathroom with no ventilation change.
Specifications
Common questions
Which surfaces does the listing name?
Tile, grout, walls, and seals. Uses also include shower. Whether it is safe on painted walls is an unanswered question on the listing.
Does the listing say you should wipe it off?
The bullets say spray on, leave it, and do not wipe. The only UK review text says wipe for removal, then leave product on to prevent.
What score and price does Amazon show?
3.8 out of 5 from 4 reviews, at £14.99 for 500 ml. That is about £29.98 per litre, the highest in this set.
Three amazon.co.uk mildew treatment listings were scored from the stored listing files and the UK review texts captured for each ASIN, plus the public pages named below. This was not a lab test. No kill percentage and no lasting-time result was added, because these listings do not state one. Stars and review depth take the largest share. The top pick is the highest star line among listings with at least 500 reviews. In this set that is one bottle at 4.2 from 2,876 reviews. A 4.2 from 15 reviews stays under that line. Surface and job come next: a fabric blocker, a wall remover, and a leave-on preventer are different products, so a deep review count on fabric does not make that bottle a painted-wall wash. Price per litre is scored against the job. The best value is the lowest price per litre, not the highest score. A missing HSE number on the scrape, a leave-on line that fights a review, a contains-liquid flag that fights the volume, and a saved review sample that is mostly outside the United Kingdom are deducted. None of the three scrapes shows an HSE number. That is not treated as approval, and no number was invented.
Stars and review depth
35%The largest share of the score. A 4.2 from at least 500 amazon.co.uk reviews sits above the same 4.2 from 15 reviews. Stars are the listing average, not a lab kill test. How many of the written texts are from the United Kingdom is part of this share.
Surface and job
30%Walls, ceilings, tile, and masonry are the decorating job. Fabric and upholstery are a different job. A remover, a leave-on preventer, and a blocker are scored as different products.
Price per litre
20%Price is the stored amazon.co.uk shelf price divided by the listed volume. The lowest price per litre can be best value without holding the highest score.
Label clarity
15%An HSE number, a leave-on instruction, and a liquid flag that agrees with the volume. A scrape with no HSE number is not scored as approved. Conflicts in the listing are deducted.
Start with the surface the label names, then whether you need a remover, a leave-on preventer, or a fabric blocker, then bottle size against the patch, then the star line and how many written reviews are from the United Kingdom. The notes below follow that order. None of these listings was lab-tested.
A mildew treatment in this paints hub is a liquid you put on a hard surface to kill or suppress mould, mildew, or algae before you decorate, or to slow regrowth after a clean. It is not an emulsion, and it is not a garden spray for plants. UK shoppers are mostly treating a bathroom ceiling, a window reveal, tiles, or a patch of painted wall. The bottle is then a remover, a leave-on preventer, or a fabric blocker. Anti-mould paint is the next coat, in another category, after the wall is dry.
A colour coat on growth you can still see does not finish the job. Dry the surface after the treatment the bottle describes, then coat. Stopping when bleach has only paled the stain leaves the cause in place. GOV.UK says use a mould and mildew product rather than bleach.
A rose or vegetable fungicide is not a ceiling wash. A fabric blocker is not a wall wash, even if one reviewer tried a ceiling. A preventer is not a promise that one spray lasts in a room that stays humid.
A listing at 4.2 from 2,876 reviews can still name fabric, and the written sample can be mostly from the United States. Count the United Kingdom texts before you treat that star line as a British decorating test. None of these three scrapes shows an HSE number.
The surface on the label is the first cut. Walls, ceilings, tile, and masonry are the decorating job. Furniture and fabric is a different job, even when a reviewer has tried a bathroom ceiling. A remover is for growth you can see. A preventer is a leave-on liquid for tile, grout, and walls. A blocker title is not a promise that thick mould vanishes in one spray. If the bullets say leave it and do not wipe, and a review says wipe for removal, keep both lines.
Size the bottle against the patch. These listings are 500 ml or 946 ml, and none prints coverage. Trade washes often quote about 5 to 10 square metres per litre on their own products, so a 500 ml spray is a patch bottle, not a whole elevation. Bartoline’s own wash quotes about 500 ml per 2.5 square metres. That figure is for that wash. Do not copy it onto a bottle that prints no coverage. Then read the amazon.co.uk star line and how many of the written reviews are from the United Kingdom.
Three typical situations, each with a recommendation from this comparison.
You are treating furniture or upholstery, which is the surface this listing names, and you want the only bottle here with at least 500 reviews. Mold Armor FG516 is the top pick, at about £25.47 with 4.2 from 2,876 reviews. Of the first 50 review texts, one is from the United Kingdom. It is the wrong bottle if you need a wall wash whose listing names painted rooms.
You have a small bathroom, kitchen, or wall patch and you want the lowest price per litre, with a title that says bleach-free. Professional Strength is the best value, at about £9.99 for 500 ml, about £19.98 per litre, with 4.2 from 15 reviews. All six review texts in the saved listing are from the United Kingdom. No reviewer states how many months it lasted.
You want a leave-on preventer for tile, grout, walls, or seals, and you will also lower the humidity. Strewth is about £14.99 for 500 ml, about £29.98 per litre, with 3.8 from 4 reviews. The only UK review text says mould returned within two weeks while humidity stayed high. The bullets say spray on and do not wipe.
The top pick is Mold Armor FG516 mould blocker, 946 ml, at about £25.47. It has 4.2 from 2,876 reviews, the only listing in this set at that star line with at least 500 reviews. The listing surface is fabric, and the uses are furniture and upholstery. Of the first 50 review texts, one is from the United Kingdom. It is the wrong bottle if you need a wall wash whose listing names painted rooms. The best value is Professional Strength bleach-free mould remover, 500 ml, at about £9.99, about £19.98 per litre. That is the lowest price per litre here, with 4.2 from 15 reviews, under the 500-review line. The title names bathrooms, kitchens, and walls. Strewth is a leave-on preventer at about £14.99, the highest price per litre, with 3.8 from 4 reviews.
Mold Armor FG516 mould blocker 946 ml
Only listing at 4.2 with at least 500 reviews. The surface field is fabric, not painted walls.
Professional Strength bleach-free mould remover 500 ml
Lowest price per litre, about £19.98, from the £9.99 listing. Not the deepest review sample.
Editorial
Peter F. is the editor for DIY & tools at productscompared.co.uk. Comparisons in this category are checked against amazon.co.uk listings, review evidence and public UK sources.
Guides on what to look for, how to use a product, and common mistakes.
Public sources from the research digest, last checked on 22 October 2026. Shelf prices and star lines are the amazon.co.uk figures stored on 19 October 2026. The price band is this set, not a market average. No listing was lab-tested.
This page contains affiliate links to amazon.co.uk. If you buy through them, we may earn a commission at no extra cost to you. Prices, stars and review counts are the stored amazon.co.uk figures, not a live crawl. We did not lab-test these treatments.
