Best thing by far I have ever used on my block paving. Tried other products, jet wash, burning, wire brush, All back braking. I have a lot of block paving that takes about 6 cars on the front and same again around the back. I would say I used 10/12 pouches and that cost around £40 but no more weeds all that year. Started to come back this year so treated again. I don’t mind paying £40 a year to have no more weeds as other stuff they were coming back after one week.