In message , Dave Baker
writes
Any good for patios and driveways or is it useless? At 30p a kilo from
Tesco for the value stuff it's a damn sight cheaper than anything else
I can find. I used to use sodium chlorate when you could still buy it
although the weeds always came back next year.

Shirley rock salt would be cheaper still? Likely to work but remember
nearby trees may have roots under the gravel.

Failing that what's the best way to deal with weeds in A) block paviour
patio and B) gravel covered driveway?

Dose of Glyphosate. Don't walk over the lawn afterward.

--
Tim Lamb