KEEP IT PERMEABLE

With increased rainfall over Autumn and Winter, many parts of the UK suffer regular flooding. Non-permeable materials like concrete and tarmac on patios and driveways contribute to this; they result in ‘run-off’, which can overwhelm our drainage systems. Choosing permeable hard materials can make a real difference – gravel and clay brick pavers, for instance, will absorb water into the soil beneath, and help filter pollutants.

Once absorbed into the soil, the water can evaporate slowly back into the atmosphere which has a cooling effect. Impermeable surfaces on the other hand, such as concrete and tarmac, absorb the sun during the day and re-emit the heat back out, contributing to the Urban Heat Island Effect (the heating of urban areas through man’s activities). Keeping hardscape permeable helps counteract this.

It’s important to use permeable base materials too, a hardcore with larger fines will allow for better drainage – we often specify MOT Type 3 instead of the contractor’s automatic go-to, MOT Type 1. The bedding layer on top should also be permeable – loose sand is ideal, or permeable mortar if a fixed bed is required.