Brick cleaner, black spots

bm_999 · 2024-10-30T07:42:42+0000

Hi all, just wondering what is the best brick cleaner to use
Have jet washed the drive and some spots on the actual sand brick right on the bottom is not coming off

Thanks

Bluecube · 2024-10-30T07:45:01+0000

Are the spots organic? If so then try a limited application of bleach.

spile · 2024-10-30T08:28:47+0000

Brick acid. Apply by brush. Leave for 10 min, rinse and repeat if necessary.

bm_999 · 2024-10-30T17:24:16+0000

Bluecube said:
Are the spots organic? If so then try a limited application of bleach.

No idea, just daw them after jet washing the drive

spile said:
Brick acid. Apply by brush. Leave for 10 min, rinse and repeat if necessary.

Any from.amazon or similar?

Simon42 · 2024-10-30T18:38:23+0000

I am starting to sound like a sales person for BAC (Benzalkonium Chloride) given my other posts!

However its more effective and longer lasting than bleach (sodium hypochlorite) although it takes a couple of months to be fully effective. This is same chemical Patio magic and Wet and Forget products use but less than a fifth of the cost!

SpellowHouse · 2024-10-30T18:49:44+0000

bm_999 said:
No idea, just daw them after jet washing the drive

Any from.amazon or similar?

You can usually only get it from a local building store, becuase these days it's outlawed for the general public. It's basically concentrated sulphuric acid.

Simon42 · 2024-10-30T18:51:46+0000

SpellowHouse said:
You can usually only get it from a local building store, becuase these days it's outlawed for the general public. It's basically concentrated sulphuric acid.

The problem with such acidic prodcuts is they fade the colour of the material they are applied to and damage the material. If you’re trying to remove organic discolouration then a biocide is the way to go.

dave28 · 2024-10-30T19:04:00+0000

Hypochlorite, leave it work for a while and then pressure wash is the method commonly used by professional pressure wash companies.

They use it to make the pressure washing more effective.

Simon42 · 2024-10-30T19:14:03+0000

dave28 said:
They use it to make the pressure washing more effective.

They use it for quick effect despite poor longevity and ignoring damage to surfaces. I started down this road many years ago with companies that would only use ‘hypo’ and realised the compromise so now use a couple of biocides for best results, no damage and best longevity.

My roof, patio, block paving and even fence panels show the benefit of a targeted treatment so I will stick with that.

Chris C · 2024-10-31T09:31:59+0000

Simon42 said:
They use it for quick effect despite poor longevity and ignoring damage to surfaces. I started down this road many years ago with companies that would only use ‘hypo’ and realised the compromise so now use a couple of biocides for best results, no damage and best longevity.

My roof, patio, block paving and even fence panels show the benefit of a targeted treatment so I will stick with that.

Could you send me a link to the products you use for this please?

Simon42 · 2024-10-31T10:28:36+0000

Chris C said:
Could you send me a link to the products you use for this please?

Just google BAC50, its available from chemical suppliers on Amazon, eBay or direct from the same suppliers. Where is best depends on delivery for the quantity you want.

DDAC is also an option but BAC is more commonly available.

Edit: For general use BAC at 2% is a good mix to dilute to for use. For ref: Patio Magic at 1:4 to water is 1.8%, Wet and Forget diluted is about 1.7% BAC

Chris C · 2024-10-31T11:06:23+0000

Simon42 said:
Just google BAC50, its available from chemical suppliers on Amazon, eBay or direct from the same suppliers. Where is best depends on delivery for the quantity you want.

DDAC is also an option but BAC is more commonly available.

Edit: For general use BAC at 2% is a good mix to dilute to for use. For ref: Patio Magic at 1:4 to water is 1.8%, Wet and Forget diluted is about 1.7% BAC

Cheers. I've been using some sodium hypochlorite and it does a decent enough job but I don't want to damage the patio and it's not a really long term solution. I'll give the BAC a try.

Simon42 · 2024-10-31T11:46:10+0000

Chris C said:
Cheers. I've been using some sodium hypochlorite and it does a decent enough job but I don't want to damage the patio and it's not a really long term solution. I'll give the BAC a try.

Just don't be put off by the very slow action unlike hypo. It will work in the end.