Thank you for your replies and suggestions. I haven't worked out how or if I can reply to each individually, so hope this covers them all.
Catpaworchids: Although I understand your suggestion to use containers or raised beds - to raise the level and enable it to hold more water rather than flood on the surface, we already have many plants, beds and trees, as well as 7 foot beech hedges all around the perimeter. We're not getting any younger so are not looking for more maintenance. An alternative – raising the level of the grass – would involve costly topsoil and re-turfing/seeding.
Crawgarden: Thank you, and for sight of that report. I would not have found it myself. It's a 60+ pages geochemical report of the soil composition of the Cardiff area. Although soil samples were taken at many sites around Cardiff, they were too shallow for my needs, only of the surface soil (up to 0.2m deep ) and profile soil (up to 0.5m deep), there is no data relating to how deep the clay layer is. It's an interesting read though.
Hamwild: I understand your thinking but we would prefer to keep the grassed areas we have, without adding more plants and maintenance.
Stone: Ours is more claypan than hardpan and as I said, after only a few inches of topsoil. 13 + feet down, it's still clay. When it's dry enough, we spend a lot of time maintaining the garden but would like to be able to use the grassed areas more, for leisure.
Porkpal: All the neighbours in our row suffer from the same issue. Our next door neighbours have a pond. To be honest I think it adds to the water retention problem as its plastic lining completely prevents any water draining in that area and the pond overflows occasionally. Plus, as our soil is only a few inches deep, digging a pond would create a mountain of unwanted clay.
Thanks again for your suggestions and help
