Do you need a membrane under turf?

Why a membrane is a bad idea

Grass roots have to push down into the soil to find water and nutrients, and to anchor the turf. A membrane stops them. The roots stay in the thin layer of soil on the turf itself, so the lawn dries out fast, struggles in hot weather and can lift like a mat.

Membranes also stop worms and soil life moving between layers, and water can pool on top of them on clay soils.

So how do you stop weeds?

Healthy, dense grass is the best weed control there is. Turf covers the soil completely from day one, leaving little room for weeds to get going. Good preparation does the rest:

• Clear perennial weeds like dandelions, docks and couch grass, roots and all, before laying
• Lift the old lawn rather than turfing over it
• Use clean topsoil where the soil needs topping up
• Lay the turf tight so there are no gaps for weeds to fill
• Mow and feed regularly once established

Already have membrane in the ground?

If you're replacing gravel or artificial grass, there's often a membrane underneath. It needs to come out before topsoil and turf go down. See replacing artificial grass with real turf.

What about root barriers?

Next to bamboo or aggressive shrubs, a vertical root barrier at the border edge can stop roots spreading into the lawn. That's different from a membrane under the turf, and it doesn't affect the grass.