Raising a lawn
I have a 20x25 foot (south facing) rear garden but suffer when the weather is bad with a lot of water retention and lawn becoming very "sponge like". This is due to there being a lot of clay underneath the lawn. House and development is built on a previous school site.
I am looking at raising the lawn by a minimum of 6inches and then laying fake turrf replacing the currently lawn.
How much soil would I need to cover the whole area 20x25ft (500sq m // 598sq yard)? Before proceeding with the relay of the new lawn/fake turf.
PS. There is a reason for the fake turf over real turf. My wife suffers with hayfever so the cutting of grass can instigate sneezing fits. Plus I feel that fake has a much more tidier feel to it.