We often get scenarios where excavation is not possible or is minimal, such as sites of archaeological value or areas where tree roots need protection. Here, the sub-base needs to be as thin as possible whilst still retaining surface loading capability. Often here, we advise laying of a geotextile layer first, then a layer of (for example) 100mm clean 20mm stone retained by our EcoGrid Cell Web, a secondary geotextile layer is then laid, and then the EcoGrid standard grids or EcoGrid Bloxx gets laid.
An EcoGrid approved geotextile layer follows to enhance surface support, provide a layer of filtration and stop the drainage layer stone from migrating up to the surface. A screed layer is laid. This can be a large granulate sharp sand or clean fine sharp angular gravel, typically 20-30mm deep-laid, leveled, and compacted.