Share
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 
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
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
Cheers,
Denis
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):
Thank you again!!
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
