How to remove green stains from a wall?

1. Green anti-scum product for terraces and roofs

Before moving on to the tips and tricks for removing green stains from wood, a terrace or a roof, here is a “pro” product to easily destroy moss, algae and other green stains.

This product is specifically designed to eliminate

• the foam
• lichens
• the seaweeds
• and other green deposits on different surfaces and materials.

The real advantage of this product is that it is antifoaming and water repellent at the same time. One step to defoam, clean and seal the surface.

And because it contains a water repellent, the duration of effectiveness against these green deposits is much longer than other products.

2. Citric acid as an antifoam

To eliminate moss on a terrace as well as lichens and algae, I offer you a first natural tip.

So if the weather is dry outside, you can use this recipe based on citric acid as a green anti deposit for wood, stone and concrete.

You need to:

• 8 liters of lukewarm water in a large bucket.
• 600 g of citric acid.
• 150g baking soda.
• 20 ml of castor or rapeseed oil.

Now here is how to use this solution on the terrace:

1. Shake well and spray this solution on surfaces with moss and green stains to be treated.
2. Leave on for 48 to 72 hours, then rinse with plenty of water or with a pressure washer.

3. Natural Defoamer with Basil Essential Oil

For those who want to try a grandmother’s recipe for removing foam, here is one with basil essential oil.

Indeed, basil has antifungal and weed-killing properties. So add a few drops of basil essential oil to water in which you also pour a few drops of liquid dish soap.

1. Spray the anti-moss solution on the moss and green spots and let it work.
2. Then brush the entire surface with a brush and let the product act again.
3. Rinse the surface with plenty of water to finish cleaning the terrace.

4. Defoamer for slabs and pavers

To quickly and effectively eliminate moss on slabs and paving, here is what to do:

1. Add coarse salt to hot water in a large bucket.
2. Apply to green and moss stained areas.
3. Leave to act for a few minutes and rinse the surface thoroughly.

This trick is very effective in dislodging green moss on slabs and pavers, whether it is a terrace or a sidewalk for example.

5. White vinegar, a natural anti-foam

White vinegar is a natural cleaning product that you can use anywhere in the house, so why not use it to remove moss and other green deposits on the terrace for example!?

Use pure white vinegar for it to be effective!

Indeed, white vinegar makes an excellent natural and free defoamer to test. Use pure vinegar, without diluting it. Simply apply it to moss and green deposits in sunny weather, leave it to act for a few minutes then rinse with plenty of water.

Vinegar can be used to clean different surfaces, including plaster, as you will also discover here: How to clean an interior plaster wall?

6. Anti-moss for the roof

If mosses, lichen or algae have invaded your roof, they must be eliminated as quickly as possible to prevent them from rotting the shingles and tiles and causing more serious and costly damage.

Start by brushing the moss with a soft bristle broom and to prevent this greenery from coming back, spray your roof with water to which bleach has been added or a product specifically designed for this purpose.

Be careful about using bleach to remove moss and green stains, as this product can discolor surfaces, you have been warned!

Other tips for roof moss removal:

If you are looking for other tips specific to roofing tile moss removal then this other article is the answer: How to demoss a roof?

Professional roof cleaning

It is important to be very careful when cleaning the roof of a house or building. It can therefore be advantageous and safe to call on a roofing specialist to carry out a complete and thorough cleaning of the entire roof.

7. Remove green spots on the terrace

How about trying another natural product for cleaning moss and lichen on a patio? Baking soda is an excellent natural product against lichen as well as mosses and greenish deposits.

Here is how to clean the terrace with baking soda:

1. In a bucket of hot water, combine 2 tablespoons of baking soda for every liter of water.
2. Apply to green stained surfaces and leave on for 30 minutes.
3. Then scrub with a push broom before rinsing with plenty of water.

Bicarbonate is an excellent grandmother’s tip for cleaning a wooden deck, but also for cleaning composite wood surfaces.

8. Remove moss from wood with black soap

Another cleaning product that you absolutely must have at home is liquid black soap.

Black soap can be useful for cleaning various surfaces naturally, including stains and green moss on wood.

1. Add liquid black soap and a few drops of dish soap to a bucket of lukewarm water.
2. Then, using a brush, scrub the areas overgrown with moss or lichen.
3. Leave on for half a day and rinse with plenty of water to remove all green deposits on the wood.

Effective also on a tiled terrace:

You can also use black soap on a stone and slab terrace as you will discover in this other article.

9. Make an anti-foam with soda crystals

To easily get rid of moss and green stains on the terrace or the facade of the house, make a mixture of hot water and soda crystals.

1. Count about 2 tablespoons of soda crystals for 1 liter of water.
2. Soak a brush and scrub the surfaces where there are greenish moss and deposits.

If the mosses are stubborn, try sprinkling soda ash directly on them before sweeping.

10. Avoid the appearance of mosses, lichens and algae

In order to avoid having to repeat this chore every year, you will have to think about preventing the appearance of mosses, lichens and algae. Once the surfaces are clean and dry, apply a water-repellent product designed for this purpose, being careful to choose a product suitable for the materials to be treated.

This product will waterproof the surface and prevent the appearance of moss and mold, ensuring a better longevity of the structure. The application must be done every two or three years, which is much better than having to clean every year!

Prevent moss and green spots on the roof:

If you want to prevent and protect your roof from moss, it is important to apply a waterproofing and water-repellent anti-moss product designed for the roof.

This waterproofing and protective product can be applied to:

• terracotta tiles
• concrete tiles
• slate tiles
• fiber cement sheets

Before applying this waterproofing on the roof, it is of course necessary to clean and remove the mosses, lichens and other green deposits already present on the roof.