Recommdations please

[RyanA85]

Hi guys,

I've got a job coming up to clean the wall attached as part of pressure washing their monobloc driveway. I know the owners have given it a go with a karcher to no avail.

I'm not planning to use pressure at risk of damaging the brick so wondering what chemicals would best remove the discolouration. Any help is appreciated.

 

[Pjj]

The white bits are effervescence it’s salts in the cement coming out @K in Kent is best to give advice on this , the rest of it will come up well with a hypo mix to kill the spores and a light pressure wash

 

[K in Kent]

I agree with Paul and would say be sure to keep pressure to a minimum and keep lance at a distance. You don't want more penetrating the bricks and activating more efflorescence. Also presure wash before using brick acid.
Keep the wall wet throughout the process and best to soak it first. Use acid sparingly and rinse thoroughly and gradually you should see the salts starting to go. But of course they might come back again depending on what the cause is so best to prepare the customer for that possibility.
Tooltation sell 2 varieties by Bostik and this one is probably the best of them and Wickes sell Sika brick cleaner which is also good for efflorescence.

But bear in mind hydrochloric acid is nasty stuff o you need PPE and apply it with care using a weak dilution and build it up a necessary. Don't let it dry out.

 

[RyanA85]

I agree with Paul and would say be sure to keep pressure to a minimum and keep lance at a distance. You don't want more penetrating the bricks and activating more efflorescence. Also presure wash before using brick acid.
Keep the wall wet throughout the process and best to soak it first. Use acid sparingly and rinse thoroughly and gradually you should see the salts starting to go. But of course they might come back again depending on what the cause is so best to prepare the customer for that possibility.
Tooltation sell 2 varieties by Bostik and this one is probably the best of them and Wickes sell Sika brick cleaner which is also good for efflorescence.

But bear in mind hydrochloric acid is nasty stuff o you need PPE and apply it with care using a weak dilution and build it up a necessary. Don't let it dry out.

Thanks to both of you guys. I had an idea it was efflorescence and as the customers karcher didn't remove I got that brick work acid would be needed after a bit of research. As with all jobs I want to give the customer value for money, they are mates with the Mrs so don't need the hassle if it were to go wrong.

I will follow the method above and of course protect myself at all times with the appropriate PPE.

Really appreciate the advice and will post finished results if it helps anyone else with a similar query

 

[K in Kent]

Thanks to both of you guys. I had an idea it was efflorescence and as the customers karcher didn't remove I got that brick work acid would be needed after a bit of research. As with all jobs I want to give the customer value for money, they are mates with the Mrs so don't need the hassle if it were to go wrong.

I will follow the method above and of course protect myself at all times with the appropriate PPE.

Really appreciate the advice and will post finished results if it helps anyone else with a similar query

The easiest way to confirm it's efflorescence is to wet the wall with a sponge and of the wet marks disappear then come back again as it dries you know it's efflorescence = water soluble sakts.
Also another thing worth trying to start with is bruhing the wall with stiff broom or hand brush to draw out the salts then wipe away with damp sponge. Believe it or not it can acrually have some effect doing that. It also works on paving.

 

[scottish cleaning service]

The efflorescence is coming from the joints in the mortar mix. Either in the water they used or the sand and it usually comes back out later on.