Project Details


Great Ancoats Street


Manchester, England


April 2021

About The Project

Great Ancoats Street is one of the main arterial routes around the city centre, and is a key part of the Manchester and Salford Inner Relief Route. With an average of 37,000 journeys most weekdays, it is a vital, and extremely busy road.

In recent years, the neighbouring areas of the Northern Quarter and New Islington have undergone major transformation and improvement. Great Ancoats Street has, until now, been left behind, and now the immediate area is a prime location for both residential and commercial development.

The plan by Manchester City Council is to not only reduce the number of accidents on this busy road, but also to landscape the area to make the route more attractive. This will include planting more than seventy trees, laying new pavements and making the area a natural extension of the city centre.

What we did

Green-tech  Specifier were contacted by Plano Landscape Contractors Ltd and COLAS, to advise the best way to integrate tree pits into the project. One of the key considerations was the amount of lateral force that would be transmitted from the highway loads.

The project had several hurdles to overcome; the main one being the level of lateral loading, which made the use of geo-cellular units impractical. Another was the extremely narrow width of  one of the central reservations, and how to maximise the rooting volume. Green-tech suggested two solutions and were invited to join a site meeting with COLAS, the main contractors, along with MJM Consulting Engineers, and Plano.

After debating various options a plan of action was agreed, featuring a combination of Green-tree Amenity Tree Soil for the central reservations, and Geo-Cellular Raft System, for the tree pits within pavement areas.

Amenity Tree Soil is a structural, sand based growing media, with a small amount of organic content. Its naturally open structure copes well with compaction, while still facilitating aeration and water percolation to the trees’ root system.

Green-tech’s Geo-Cellular Raft System acts as an extremely rigid, geo-cellular sub-base replacement, supporting the paving above, as well as protecting the tree pit soil below from compaction. Working on a raft principle, a key benefit of using the Geo-Cellular Raft System is that no plastic extends into the actual tree pit rooting area.

Green-tech’s Specifier department in conjunction with MJM, designed and produced CAD drawings for the tree pits, which once approved by COLAS and the engineers, went before Manchester City Council for final sign off.

Between March and November 2020, Green-tech delivered in 1,300 tonnes of Amenity Tree Soil and Subsoil, over 800m2 of Geo-Cellular Raft units, 1.1kms of gtRootbarrier® 325, along with seventy tree anchors and Mona Link 24 irrigation reservoirs.

The final tree planting was completed at the end of 2020 and we look forward to seeing them in leaf during this coming Summer.

"On a far from straight forward project, it was good to work with a company like Green-tech in such a collaborative manner, who understand the issues and can come up with realistic, workable options."

Andy Dickson – Director – MJM Consulting Engineers

"It is not the first time that we have provided tree pit solutions for Manchester City Council, and it was good to be able to work with not only the landscape contractor, but also the main contractor and consulting engineers, in order to achieve the best way forward for this high profile project."

Alasdair Innes – Green-tech Specification Advisor: