The risk you are actually managing
Brick cleaning is one of the cheapest line items on a house and one of the most expensive to get wrong. A burned elevation cannot be patched — it has to be chemically remediated across the whole wall so the finish stays even, and on a bad one the only honest answer is render or replacement.
The other exposure is timing. Cleaning too early rakes out green mortar joints. Leaving it until the scaffold comes down and the landscaping is in means working around finished surfaces at twice the care and half the speed.
