How to remove water stain on garden bed concrete blocks?

[Rhyan]

Hi guys,

I need some help and advice how to clean/remove the water stain marks on my garden bed concrete blocks? Also how to prevent this to happen again? Do I need to paint it or apply any water proofing paint?

Appreciate your help.

[Jewelleryrescue]

Hi @Rhyan 

I have a wall  i want to keep clean too from whipper snipper grass stains and other dirt splashing up.

Well to partially clean (As it is already stained) it a high pressure washer is the strongest solution. Next apply aa clear sealer.

 A concrete block wall could use a heavy-duty sealer

This will help repel further stains

An additional  idea is to add low garden edging strip    (many  types avaliable.)to ward of grass cutting mess etc,

Hope this helps

[MitchellMc]

Welcome to the Bunnings Workshop community @Rhyan. It's brilliant to have you join us, and many thanks for your question about sealing blocks.

To tackle the water stains on your garden bed concrete blocks, it’s important to first understand where the moisture is coming from. If the water is coming from outside, applying a clear sealer to the blocks would likely help prevent further staining. This would block the absorption of water and help protect the surface of the blocks. A concrete sealer such as Dulux 4L Clear Matt Concrete And Paving Protective Sealer should be suitable.

However, if the water is coming from inside the garden bed, such as moisture seeping out through the bottom, the solution becomes a bit more complicated. You may need to remove the soil to access the inside of the blocks and apply a sealant to the wall to prevent moisture from leaking out. It’s important to note that sealing the wall on the inside might not entirely solve the issue if moisture is wicking up from the lower blocks, which could still lead to staining.

Please let me know if you have any questions.

Mitchell
 

[Rhyan]

Hi Mitch,

Thank you for your wonderful response.

I’ve been monitoring my whole garden bed concrete block and noticed that the water stain caused and came from the inside of my garden bed.

When I turned on my water irrigation I set it up in my garden bed after a few minutes watermarks/moisture started to show up on the same area of the water stain.

Also, yesterday while cleaning my artificial turf I noticed some mould on the lower part of my garden bed.

I pressed wash the wall and some of the moulds and stains have been removed but not all.

Not sure how to fix the issue as I am concerned about the moulds that started to grow on the lower part of the garden bed.

I truly appreciate any advice or information you guys can give me to tackle this issue.

[MitchellMc]

Hi @Rhyan,

Retaining walls are often exposed to moisture due to the nature of retaining damp soil, so it's common to see moss, mildew, and organic buildup on their surface over time. Regular cleaning with a high-pressure sprayer is essential to maintain their appearance and prevent mould growth. Doing this at least once a year will help keep the wall looking its best.

Mitchell