My brick driveway down the side of my house to my garages does not get any sun on it during Winter and the moss growth is severe. I found a product in New Zealand called 30 seconds, but it is not available in South Africa. I have tried bleach and patent moss removers but they just do not work. Any ideas how to kill it off so that it can be pressure washed away?
Try pouring on undiluted white vinegar, leaving it for 10 minutes, then use the pressure hose. (You know you want to!)
Salt should work as well.
Can’t help you with brand names – don’t know what they have in your country.
In the lawn and garden shop there are three kinds of moss killer.
The kind for lawns contains iron; it kills moss quickly and it is good for grass (makes it green but doesn’t make it grow faster) but it will cause rust stains on walks and driveways.
For walks and roofs there are two types; one contains zinc and the other contains ammoniated soap of fatty acids. The zinc stuff works well, the ammoniated stuff not so much.
Most decent pressure washers can handle live mold/moss without prep. You don’t need to “kill” the moss beforehand.
Rebuild your driveway with rolling stones.
I use a garden sprayer and a solution of cheap washing soda (sodium carbonate). A few days later, I brush it off with a stiff construction broom.
I used to use a pressure washer but have found that over the years it has abraded the surface enough to actually worsen the moss situation by providing lots of nooks and crannies for the moss.
The first year I used the pressure washer but boy, does that make a mess everywhere and removes the sand between the bricks that then fills up with soil. I thought about using swimming pool acid, but would have no idea as to what dilution to use. I will try the soda route first and see.