Assuming you are not over-watering, my solution is to improve drainage in the lawn. Go over the whole lawn with a garden fork and puncture holes all over it. Every so often lift the lawn - you will hear the roots strain. Through some sand lightly over the lawn. It will look dreadful for a few weeks but it will be fine within a month.

Assuming you are not over-watering, my solution is to improve drainage in the lawn. Go over the whole lawn with a garden fork and puncture holes all over it. Every so often lift the lawn - you will hear the roots strain. Through some sand lightly over the lawn. It will look dreadful for a few weeks but it will be fine within a month.

Improving drainage is very important, so spike all over as Kildermorie suggests. Then apply nitrogen as sulphate of ammonia - this may cure the problem, but you will need to keep the lawn regularly fed (April and June) and aerate twice a year, spring and autumn. If you're sure its red thread that is, it usually only affects fine or luxury turf grasses.

thanks both for the response much appreciated