Tree Protection Zone

Paving around mature trees without sealing the roots

Ordinary concrete caps a root zone. Rain runs off it into a gutter or a garden edge, and the soil beneath goes short of water and oxygen. Leave the ground bare instead and people wear their own track through the mulch bed within a season. Neither result works on a site where the tree has to stay.

This job needed a surface that could sit hard against the trunk without cutting the tree off from rain. We poured permeable concrete around the base of each tree and tied the new surface into the paths already running past it. Trees kept their water, walkers kept a path.

Our concrete is made differently to a standard footpath mix: 20 to 25 per cent of it is open voids, linked from the surface down through the base. Air reaches the soil. Rain soaks straight down to the roots instead of sheeting off toward a stormwater pit.

Joined to the footpaths

We tied the new paving into the adjoining footpaths rather than leaving each tree as an island. The route carries straight on, no gap and no detour. On site, the grey edge of the new path meets a fresh bed of mulch at the foot of the trunk, with the site fencing still standing behind it. Feet stay on the path. The tree keeps its ground.

Trees kept, paths open

The established trees on this site stayed put instead of coming out for a driveway or a car park. Once the fencing came down, the surface was ready to walk on the same day. See our tree protection zones page for more on working near root zones. Each tree, and each site, gets its own design.