Interesting posts- they have helped me recognise there's not much I can do with my clay-pan of a back lawn! It's completely flat, 13m x 10m, with the classic patio along one long edge and 3 garden beds around the other 3 sides, and you can literally make little clay pots from the lumps of clay in the soil! I compost, horse manure, soil condition it every year so it's improving, gradually (clay soils are allegedly more fertile), but the lawn is an undulating mass of moss- previous owners have cut beds and infilled them hence the Telly-Tubby bumps! I have considered, in re-landscaping the back garden, reducing the size of the lawn, then levelling the lawn area, gravelling it etc before relaying it but I wonder if I'm wasting time and money as the fact is, the effectively trapped water has nowhere to drain to, either down or laterally.