Patio black spot removal with Bleach
- Thread starter Carolyn1
- Start date
Welcome to the forum Carolyn1. 
I'd not advise anything be put through a pressure washer not recommended by the pressure washer manufacturer.
My wife Bron brings our patio up like new simply by pouring cheap Morrison's vinegar on and brushing the vinegar in; a squirt of washing up liquid and a small amount of water from a bucket froths it up; the result is outstanding. A soft sweeping brush is used not requiring much effort; if the patio is very dirty just repeat this a number of times.
I used to pressure wash the patio twice yearly creating a right mess with lots of noise and an aching back whilst trailing a power cable and water hose around; Bron likes using the vinegar which only costs around 21p per litre. doing the job in a few minutes, Hope this helps you.
Kind regards, Colin.
I'd not advise anything be put through a pressure washer not recommended by the pressure washer manufacturer.
My wife Bron brings our patio up like new simply by pouring cheap Morrison's vinegar on and brushing the vinegar in; a squirt of washing up liquid and a small amount of water from a bucket froths it up; the result is outstanding. A soft sweeping brush is used not requiring much effort; if the patio is very dirty just repeat this a number of times.
I used to pressure wash the patio twice yearly creating a right mess with lots of noise and an aching back whilst trailing a power cable and water hose around; Bron likes using the vinegar which only costs around 21p per litre. doing the job in a few minutes, Hope this helps you.
Kind regards, Colin.
Is is a hand operated pressure sprayer (the type with a manual pump handle and lance) or a high-power pressure washer that is mains powered?
I definitely wouldn't use bleach in a mains powered pressure washer, but I'd happily use it in a cheap pump sprayer (and have done so before). I would be very careful about using bleach to clean your patio, as it could make it worse depending on the stone - if you do use it, be sure to dilute it! We have a sandstone patio that was covered in black spots and we had a lot of success with some "green away" product a few years ago (cost about £8 and diluted 3:1). Just be sure to do a test patch. It did take a few months for the black spots to fade.
Colin's method of using vinegar looks like a really cheap and relatively gentle way of cleaning paving, so may be worth a try first!
I definitely wouldn't use bleach in a mains powered pressure washer, but I'd happily use it in a cheap pump sprayer (and have done so before). I would be very careful about using bleach to clean your patio, as it could make it worse depending on the stone - if you do use it, be sure to dilute it! We have a sandstone patio that was covered in black spots and we had a lot of success with some "green away" product a few years ago (cost about £8 and diluted 3:1). Just be sure to do a test patch. It did take a few months for the black spots to fade.
Colin's method of using vinegar looks like a really cheap and relatively gentle way of cleaning paving, so may be worth a try first!