How to deal with clay in new home build?

Mel87

Hi All! We're building our first home, and are planning landscaping around. After rain we realised the clay on the block is causing water to pool around. 

Since we literally have a clean slate to start from, we want to do it right. 

How can we best prepare the clay soil for optimal drainage around the house? We plan part of the garden to be lawn, part to be garden beds, and part to be pathway, either concrete & stone or pebbles and stepping stones. 

Any words of advice are welcomed! 

JacobZ

Hi @Mel87,

Welcome to the Bunnings Workshop community and congratulations on your new home.

There are a few things we should look to do in the coming weeks and months to set your home up for success.

Since clay holds water, start by installing subsurface drainage and grading the block so it slopes away from the house. 

Installing subsurface drainage, like a French drain or agi pipe, that is connected to the council stormwater system, will help move excess water, especially in low-lying areas. Consider installing French drains around the foundation of your home and having a plumber connect them to your stormwater outlet. Check out How to install garden drainage for some guidance.

For garden beds, improve soil structure by applying gypsum to break down clay, then mix in compost, manure, and coarse sand to boost aeration. Before planting, aerate deeply with a garden fork or aerator.

For the lawn, spread 100–150mm of topsoil over the clay to improve drainage and choose hardy grasses like Kikuyu, couch, or Zoysia. Over time, the growth and subsequent breakdown of root structures will help to add natural compost and nutrients to the clay, helping to improve the soil structure. 

For pathways, solid surfaces like concrete or pavers should be slightly sloped to prevent pooling, while permeable options like gravel or stepping stones will allow water to seep through.

Installing adequate drainage is the best thing you can do at this point of the journey. I would suggest consulting with a plumber about this as a first step.

Let me know what you think and if you have any further questions, please don't hesitate to ask.

Jacob