Often we get scenarios where excavation is not possible or is minimal such as sites of archaeological value or in areas where tree roots need protecting. Here the issue is that the sub-base needs to be as thin as possible whilst still retaining surface loading. 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 is laid.
An EcoGrid approved geotextile layer follows to enhance surface support, provide a layer of filtration and to stop the drainage layer stone migrating up to the surface. A screed layer is laid; this can be a large granulate sharp sand or clean fine sharp angular stone, typically 20-30mm deep laid, levelled and compacted.