Remove 'scudding' from red brick?

[stevethespreader]

stevethe spreader,
I'm not in any way personally attacking you, and
I'm not, of course, suggesting that such companies dont literally exist - I'm saying that what they do in practice is not restorative but damaging.
I write from my experience of whatever, & my experience of restoration companies & their results is not happy.

I would still approach one of these company's and ask what they would do to get some idea as to the best method to get the slurry off rather than just going at it blind

 

[chappers]

So you are suggesting that the OP should apply the acid & chemical potions you mentioned above to that c/breast in that room?
How would you propose to clean them off?
If you were only proposing chemical cleaning then why mention jet washing?

The building photos in your references are best seen 12 months, or 2 to 3 years after such treatment. They prove nothing in terms of this thread.
Of course, anything can be power cleaned - water lances are used to cut re-barred concrete, & remove all patina from any brick or masonry.

I'll note a single example that was power cleaned 44 yrs ago and has had issues ever since. The Royal Albert Hall in London. Massive damage was caused with long term effects - much of the fabric, terra cotta and brick, has since disintegrated.

No I wasn't suggesting anything of the sort just pointing out how it was done on a property and how mechanically removing it with a grinder would cause obvious damage.
Not sure what has happened to my original post as I can't see it, but there all I suggested was speaking to a brick restoration company to see if they had any advice or having a bit of a scrub with brick acid.
As for the Albert Hall you say that was 44 years ago, well things have moved on a lot from then and the days of leaving water jets on a building for days to remove dirt are pretty much gone on all but the toughest stone, the methods used now on historic buildings are actually almost exclusively chemical based followed by low abrasion scrubbing and low pressure mist rinsing. The appropriate method is to start with the water and light brushing going up through different strengths of cleaning products with the ultimate realisation that sometimes it won't be possible to clean at all.
Where water spraying is used nowadays on historic buildings it is almost exclusively short duration mist spraying followed by light hand brushing

Have a look here

Lets keep things in context here, you mention the Albert hall I mentioned a Victorian terrace and the OP is talking about a chimney breast.
The one thing I will agree on though is that whatever method you use on whatever building the finished result will never be like the original.

 

[stevethespreader]

Ok let's get things right here neither the terrace house or the Albert hall had tanking slurry splashed all over it the house was painted and there are chemical peels for that now, and the Albert hall was most prob a build up of grime and dirt over the years , tanking slurry is a different kettle of fish

 

[stuart45]

Have a look here

The author has written a book on the subject.
https://books.google.co.uk/books?id...rk of royal albert hall from cleaning&f=false