David wrote:

looked good except for the couch grass growing through it

Mine has MOT1 whackered, sand whackered, weed membrane then the turf
nailed down, weeds don't get much of a foothold and are easy to pull
out, maybe 2-3 times a year.

Moss that falls from the roof does tend to grow, easy to kill with iron
sulphate, but then it turns black and doesn't rot away - every couple of
years I give it a good scrape with a dog rake.