Affiliate disclosure: PestPro Index is reader-supported. When you buy through links on this page, we may earn a small commission at no extra cost to you. This helps us keep the site running and free for everyone. As an Amazon Associate, PestPro Index earns from qualifying purchases.
The products here run in the order you use them. The HG Mould Spray is for clearing mould off walls, tiles and grout, and the HG foam suits you if you want it to stay where you spray. Zinsser B-I-N covers a stain that keeps showing through new paint, and the Ronseal and Johnstone’s paints are the finishing coats.
Products Compared
Every column below is what the Amazon listing itself states. Where a listing does not state something, the cell says so rather than guessing.
| Product | Size and coverage, as listed | Active or base, as listed | Label |
|---|---|---|---|
| HG Mould Spray | 500ml spray | not stated | Best Overall |
| HG Mould Remover Foam | 500ml foam spray | sodium hypochlorite | Best for Porous Surfaces |
| HG Mould Spray x2 | 2 x 500ml spray | not stated | Best Pre-Paint Preparation |
| Zinsser B-I-N | 1 litre primer, 12.5 m²/litre | shellac primer | Best Stain Blocker |
| Ronseal Damp Seal | 500ml sealer | polyurethane, synthetic rubber | Best Damp Sealer |
| Ronseal Anti Mould Paint | 750ml paint, 13 m²/litre | not stated | Best All-Rounder |
| Rapide Spray Paint | 400ml aerosol | not stated | Best for Small Areas |
| Johnstone's Cover Damp | 750ml paint, 3 m²/litre | not stated | Best for Damp Patches |
Two of these listings, the Ronseal damp seal and Johnstone’s damp paint, say to fix the cause of the damp before you use them (Start with the cause).
Best Overall — HG Mould Spray 500ml
Spray
HG Mould Spray 500ml
Best Overall
- 500ml trigger spray
- Listed with a bleaching effect; the listing says to test first in an inconspicuous place
- Listed for plastered walls, tiles, bathroom seals, grout and windows
- Listed for indoor or outdoor use
- Listing does not name the active substance
As an Amazon Associate, PestPro Index earns from qualifying purchases.
Start here to clear mould off the surface before anything else goes on. The 500ml trigger spray is listed for plastered walls, tiles, bathroom seals, grout and windows, indoors or outdoors. It has a bleaching effect, so the listing tells you to test it somewhere out of sight first.
Pros:
- 500ml trigger spray
- Listed for walls, tiles, seals, grout and windows
- For indoor or outdoor use
Best for Porous Surfaces — HG Mould Remover Foam Spray 500ml
Spray
HG Mould Remover Foam Spray 500ml
Best for Porous Surfaces
- 500ml foam spray; the listing says the foam stays on the surface longer than a liquid
- Listed as containing sodium hypochlorite, with a bleaching effect
- Listed for plastered walls, tiles, bathroom seals, grout and windows
- Listed as low odour; test first in an inconspicuous place
As an Amazon Associate, PestPro Index earns from qualifying purchases.
Pick the foam if you want the product to stay where you spray it. The listing says it stays on the surface longer than a liquid and reduces splashing, names its active as sodium hypochlorite, and calls it low odour. It has a bleaching effect, so test it somewhere out of sight first.
Pros:
- Foam stays on the surface longer than a liquid, per the listing
- Active named: sodium hypochlorite
- Low odour, as listed
- Listed for walls, tiles, seals, grout and windows
Best Pre-Paint Preparation — HG Mould Spray 500ml, Pack of 2
Spray
HG Mould Spray 500ml — Pack of 2
Best Pre-Paint Preparation
- Two 500ml sprays; listed at 1,000 millilitres in total
- Listed with a bleaching effect; test first in an inconspicuous place
- The listing says to check the label for surfaces it is not recommended on, naming wood and plastic
- Listing does not name the active substance
As an Amazon Associate, PestPro Index earns from qualifying purchases.
Two of the HG sprays in one pack, a litre in total, for when there is more than one patch to clear before the primer and paint go on. It has a bleaching effect, and the listing says to test first and to check the label for surfaces it is not recommended on, naming wood and plastic.
Pros:
- Two 500ml sprays, 1,000ml in total
- The same HG Mould Spray as our overall pick, in a pair
- Label guidance on surfaces to avoid, naming wood and plastic
Best Stain Blocker — Zinsser B-I-N Primer-Sealer & Stain Killer 1L
Product
Zinsser B-I-N Primer-Sealer & Stain Killer 1L
Best Stain Blocker
- 1 litre shellac-based stain-blocking primer
- Coverage listed as 12.5 m² per litre
- Listed for interior ceilings, walls and doors, and spot priming outside
- Listed as blocking water, smoke and tannin stains and odours
As an Amazon Associate, PestPro Index earns from qualifying purchases.
Use this once the mould is off and the wall is dry, when a mark keeps showing through new paint. It is a 1 litre shellac-based primer, listed at 12.5 m² per litre for interior ceilings, walls and doors and for spot priming outside. The listing describes it as blocking water, smoke and tannin stains and odours, and it makes no mould claim.
Pros:
- Shellac-based stain-blocking primer
- 12.5 m² per litre, as listed
- Blocks water, smoke and tannin stains, per the listing
- For interior walls, ceilings and doors
Best Damp Sealer — Ronseal One Coat Damp Seal 500ml
Product
Ronseal One Coat Damp Seal 500ml
Best Damp Sealer
- 500ml one-coat damp seal, white
- The listing says it can be applied to damp walls and painted or papered over when dry
- The listing's own instruction: make sure the cause of damp has been fixed first
- Coverage not stated on the listing
As an Amazon Associate, PestPro Index earns from qualifying purchases.
This suits a wall that is still damp after the cause has been dealt with. The listing says the 500ml white seal can go onto damp walls and be painted or papered over when dry. Its own instruction is to make sure the cause of damp has been fixed first, and coverage is not stated.
Pros:
- One coat, as listed
- Can be applied to damp walls, per the listing
- Paint or paper over it once dry
- 500ml, white
Best All-Rounder — Ronseal Anti Mould Paint 750ml
Product
Ronseal Anti Mould Paint 750ml — White Matt
Best All-Rounder
- 750ml white matt paint
- Coverage listed as 13 m² per litre
- Listed as washable; brush listed as included
- The listing carries a detail table and no feature text — how it acts on mould is not stated
As an Amazon Associate, PestPro Index earns from qualifying purchases.
A finishing coat for the room once the wall is clean and sealed. It is 750ml of white matt paint, listed at 13 m² per litre and as washable, and a brush comes with it. The listing does not say how the paint acts on mould.
Pros:
- 13 m² per litre, as listed
- Washable white matt finish
- Brush included, as listed
Best for Small Areas — Rapide Anti Mould Spray Paint 400ml
Spray
Rapide Anti Mould Spray Paint 400ml
Best for Small Areas
- 400ml aerosol, white
- The listing's only feature line: protects walls and ceilings from mould growth
- Coverage in square metres not stated
- Active substance not stated
As an Amazon Associate, PestPro Index earns from qualifying purchases.
An aerosol suits a small area where a tin and a brush are more work than the job. This one is 400ml and white, and the maker's one feature line says it protects walls and ceilings from mould growth. No coverage figure and no active substance are stated.
Pros:
- 400ml aerosol, white
- For walls and ceilings, per the listing
- No brush or tin to clean
Best for Damp Patches — Johnstone's Paint to Cover Damp 750ml
Encasement
Johnstone's Paint to Cover Damp 750ml — White
Best for Damp Patches
- 750ml white paint for plaster, brickwork, cement and stone, as listed
- Coverage listed as 3 m² per litre — about 2.25 m² from one tin
- The listing says it can be over-coated with the maker's emulsion
- The listing's own note: ensure the reason for the damp is fixed
As an Amazon Associate, PestPro Index earns from qualifying purchases.
This is for a patch of damp staining once the reason for the damp is fixed, which the listing itself insists on. It is 750ml of white paint for plaster, brickwork, cement and stone, listed at 3 m² per litre, so a tin covers about 2.25 m². The listing says you can over-coat it with the maker's emulsion.
Pros:
- For plaster, brickwork, cement and stone
- 3 m² per litre, about 2.25 m² a tin
- Over-coat with the maker's emulsion, per the listing
Start with your situation
- You are a social landlord with a report of damp or mould. The guidance sets fixed timeframes for investigation and work — what the guidance requires.
- You do not yet know what is causing it. Ronseal and Johnstone’s both tell you to fix the cause before you open the tin — start with the cause.
- You have painted over it before and it came back. That is the case these products are not for — where they do not work.
- You need to clean an existing patch. Three HG sprays here, one of them a foam — the 500ml spray, the foam and the two-pack.
- You need to redecorate a stained but dry wall. A primer first — Zinsser B-I-N or Ronseal Damp Seal — then a paint.
Warning
The HG foam is listed as containing sodium hypochlorite, and all three HG sprays are listed with a bleaching effect. Each listing says to test on an inconspicuous area first and to keep the spray off clothing and gloss paint.
Start With the Cause, Not the Tin
Two products on this page carry the instruction on their own listings. Ronseal’s One Coat Damp Seal says, before you start, make sure the cause of damp has been fixed. Johnstone’s Paint to Cover Damp says to ensure the reason for the damp is fixed. Neither product claims to do that for you.
The government’s guidance for social landlords puts the same point the other way round. Where a hazard comes from the building, the landlord owns the cause: “Where a hazard is caused by a structural defect or deficiency, such as poor design or missing components, the landlord is responsible for addressing the root cause under Awaab’s Law.” (GOV.UK). A tin of paint does not discharge that.
What Awaab’s Law Guidance Requires
The guidance fetched for this page is the one written for social landlords in England. It sets timeframes rather than products. A social landlord must “Investigate any potential significant hazards within 10 working days of becoming aware of them” and “Undertake relevant safety work within 5 working days of the investigation concluding, if the investigation identifies a significant hazard.” (GOV.UK). The guidance treats damp and mould as a hazard to health, and this page goes no further into that than the guidance does.
It also closes off one explanation: “It is unacceptable for social landlords to assume that the cause of a hazard, such as damp and mould, is due to the tenant’s ‘lifestyle’.” Nothing on this page holds a fetched source on how or when these timeframes reach private tenancies, so this page does not say.
Where These Products Do Not Work
On a wall that is still wet. The sealer and the damp paint both say the cause must be fixed first. A stain blocked while the water is still arriving is a stain that will return through the new coat, because nothing about the wall has changed.
As a mould killer, if the listing does not say what is in it. Of the three HG sprays, only the foam names its active substance. The two anti-mould paints and the aerosol name none at all. The comparison table says “not stated” where that is the case, and this page does not fill the gap.
As a full-room paint, from a 750ml tin. Johnstone’s listing rates its damp paint at 3 m² per litre, which is about 2.25 m² from the tin on this page. That covers a patch, not a room, and the label on its card says so.
What Decides the Choice
1. Clean, block or coat
The sprays remove what is on the surface. The primers stop a mark from coming through a new coat. The paints are the finish. They are not substitutes for one another, and the order of work below is the reason eight products sit on one page.
2. Whether the listing states coverage
Three listings give a figure: Zinsser at 12.5 m² per litre, Ronseal Anti Mould at 13 m² per litre, Johnstone’s at 3 m² per litre. The other paints and the sealer state none. Buy by the stated figure and the area you have measured, not by the size of the tin.
3. Whether the listing names the active substance
One does — the HG foam, sodium hypochlorite. For a landlord recording what was used in a property, that is the difference between a product you can name on a job sheet and one you cannot.
If Paint Is Not the Answer
Find the water. Condensation, a leak and rising damp are different faults with different fixes, and nothing on this page tells them apart. Our damp and mould equipment page covers meters and monitoring.
Reduce the moisture in the air. Where the cause is condensation, a dehumidifier addresses the air rather than the paint.
Get the investigation done. For a social landlord the guidance above fixes the timeframe, and a survey is a different job from a spray.
Order of Work
- Fix the cause. Both the sealer and the damp paint say so on their listings.
- Clean the surface. A spray or foam, tested first on an inconspicuous area as each HG listing says, and kept off clothing and gloss paint.
- Let it dry. The sealer is the one product here listed for application to a wall that is still damp; the others are not.
- Prime the stain. Zinsser B-I-N or Ronseal Damp Seal, by the coverage figure where one is stated.
- Coat. Then the finish paint, again by the stated coverage and the area you measured.