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Hello!
Hoping for some advice on how to thoroughly clean sandstone bricks.
As you can see by the photos attached we have quite a bit of discoloration happening.
We have tried water blasting with a gurnie, but unfortunately it didn't make any difference..
All suggestions / advice welcome!
We are also wondering if it is worth painting (if you can paint sandstone)?
Thanks heaps!
B
Welcome to the Bunnings Workshop community @Benita152. It's terrific to have you join us, and many thanks for your question about cleaning sandstone.
I'm surprised to hear that using a high-pressure washer did not make any difference as they are normally highly effective with this type of work. The growth on the wall looks to be the same as what's on the concrete, and a pressure washer would remove that with ease; the concrete would look like new afterwards. Did you try the Gerni on the concrete, and if so, what effect did it have? For there to be no effect at all, I'd have to presume the machine could possibly be faulty.
Typically, this type of growth on blocks should be easily removed with a pressure washer. Occasionally, you can have black staining that has penetrated the block, which is impossible to remove with water blasting, but that doesn't appear to be the case here. To remove staining or stubborn growth, it's best to use the pressure washer in combination with a chemical cleaner. I recommend giving the wall a scrub down with a stiff bristle broom and 30 Seconds 5L Outdoor Cleaner Concentrate. Once done, you can use the pressure washer to remove the loosened material. Remember your PPE when using the cleaner and pressure washing, including safety glasses, a long-sleeved shirt, trousers and enclosed footwear.
Please let me know if you have any questions.
Mitchell
