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How to clean stains off mortar?

denisl
Getting Established

How to clean stains off mortar?

Hi there,

I wanted to ask what might be a good product / method for cleaning black stains from mortar. I am not sure what type of stain it is (probably mold). There are 3-4 places around the property where the staining occurs. The house is around 30 years old.

I was thinking something like this : https://www.bunnings.com.au/30-seconds-2l-one-step-spray-and-walk-away_p4460169 ? I had great luck getting mold stains off cladding with that.

Thank you in advance :smile:20240526_101515.jpg20240526_101523.jpg20240526_101529.jpg20240526_101548.jpg20240526_101733.jpg20240526_101949.jpg

MitchellMc
Bunnings Team Member
Bunnings Team Member

Re: How to clean stains off mortar

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

30 Seconds 2L One Step Spray And Walk Away sounds like a good starting point. If you haven't already done so, you might like to hit the area with a high-pressure washer before the spray to see if it lifts any of the stains. Spray and walk away can take some time to work and might require a second application. I'd recommend you give it a go and let us know if you don't see any effect.


Please let me know if you have any questions.

Mitchell
 

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denisl
Getting Established

Re: How to clean stains off mortar

Thanks very much for a warm welcome and a prompt and detailed reply. I will give this a go some time this week and report back :smile:

 

Cheers,

Denis

denisl
Getting Established

Re: How to clean stains off mortar

Howdy howdy,

 

I used a gerni to pressure wash all the stains and I have to say about 90% of it came off, thank you very much for your suggestion!

As for the remainder of the stains (in some areas only), would you recommend I give the spray and walk away a shot?

After pics (I am purposely selecting the worst areas, most of it is 100% gone):

20240528_132703.jpg20240528_132716.jpg20240528_132806.jpg

Thank you again!!

EricL
Bunnings Team Member
Bunnings Team Member

Re: How to clean stains off mortar

Hello @denisl 

 

For tough imbedded stains a second application of 30 seconds is sometimes necessary. I would also suggest using an Oates Long Handle Grout Brush to help with the cleaning. 

 

If you need further assistance, please let us know.

 

Eric

 

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