How long

will this last. I know this is a boring picture but need a record of driveway in pristine (or as near as) clean condition. We have tried over the past few years to keep weeds down but its a soul destroying task. Under the caravan (its on its hols) it becomes a real growth area, and, of course, you cannot reach under.
So this week-end whilst car and caravan away we arranged for it to be tackled. We have pressure washed it many times. Chap who did it says its his least favourite job. Took him ages cleaning the road outside.*Today he has spread sand which has a weed killer in and we hope it will last(for ever) a long time.
* from all the dirt which had washed down