08–10 OCTOBER 2019 | NEC | BIRMINGHAM News
Site Boundary Wall for NHBC Scheme
Taylor Wimpey (East Anglia) invited GeoGrow® to provide a Rootlok® retaining wall solution for two perimeter walls for their brand-new development of 288 high-quality homes in Manningtree Essex.
The site boundary bordered existing residential back gardens which were at a high ground level, we were approached by Taylor Wimpey with a brief to create as much of a back garden plot sizes as possible, with limited space to play with. The perimeter walls needed to have as small a footprint as possible, with the walls as high as 6M it was going to be a challenge not only in the design but for the overall installation.
GeoGrow provided a full formal design inc PI in accordance with the relevant British Standards & Euro Codes for an earth reinforced retaining structure incorporating geogrids with various backfill lengths. Where the wall required a small footprint the back slope was stabilised using 3.5M long galvanized steel pins. StrataGrid BBA certified SGU60 geogrids were installed with the Rootlok system being used as a facing to the structurers providing an immediate erosion protection system and medium to provide a vegetated, sustainable green finish.
Installation was restricted to 20M lengths to maintain the stability of the backslope and allow for the safe installation of the geopins which were laid in a pattern of 0.84m vertical and 0.50m horizontal centres, as per the design.
We were able to reduce the section of the wall, where the smaller footprint was required to a 1.5M width at the toe of a 5.3M high wall. Further approval was gained to use an IBA recycled granular stone which was compacted (in accordance with Method 2, Table 6/4 of the MCDHW Specification for Highways Works). testing was undertaken during installation.
GeoGrow undertook the full scope of works which started in November 2020 and completed the build within schedule in February 2021, while dealing with extreme weather conditions. On completion the walls were hydroseeded by GeoGrow’s in-house hydroseeding team with a seed mix to the Clients specification, where overtime the walls will fully vegetate to provide a sustainable green finish.
Rootlok is a cost-effective system that provides end users with a strong, yet flexible, green solution for retaining walls. It’s ability to vegetate creates a retaining wall that blends seamlessly with the natural environment. It is important to consider the choice of vegetation to ensure that the result is aligned with expectations and the ability to effectively and safely maintain it.