Solving a wet lawn problem
Most lawns created on a clay or heavy soil suffer from a wet or badly drained surface, this is often caused by unstructured or heavy soil. In some cases a badly drained surface on a lawn can be down to simple bad drainage but before installing a new drainage system you should try to improve the surface of the lawn.
By simply applying a number of dressing of sand over the lawn using a shovel or spade and brushing it into the surface of the lawn you will build up a sand carpet at the base of the grass plants in the lawn creating a surface thats more free drained.
The 2 keys are to firstly apply a sand which is made of particles of a similar size such as a kiln dried sand used for block paving or a sand used for a child’s play sand pit. A standard building sand used for laying bricks etc will have a particles that are all different sizes and so it is not suitable because it creates a solid mass with few air spaces.
Secondly apply the sand so it does not smoother the grass totally so that the grass will recover and grow through the newly applied sand carpet. Ideally you need to apply 4 applications of sand over 3 to 6 months. Ideally you are aiming to create a sand carpet at the base of the grass plants 15mm to 25mm in depth.
If the lawn is uneven in the hollow areas you can add more sand mixed with 50 percent soil to remove the low spots. In these areas the grass is likely to get smothered and might not fully regrow so over-seeding will be required in the spring or autumn.
Sand can normally be purchased in 800KG bags delivered to your home address by your local builders merchant. Here is a link