MatsGrids MG40 Installation Guide for Porous Paving
The surface may be trafficked immediately after filling but it is preferable to allow the grass to become established before full use.
- The product is asymmetric and must be lifted by placing the hands on the diagonally opposed corners of the central paver.
- Place grids onto the prepared well consolidated bedding layer. Edging strips or boards should be used where required, according to ground conditions
- Connect the grids using the patent pending interference loops, progressing over the area in manageable sections. Additional pins can be used at edges to further strengthen the final installed project. Use protective gloves to avoid abrasions.
- Grids can be cut using a hand or power saw to fit around obstructions and curves. Cut pieces which are less than 50% of original size should be avoided if at all possible. Fill pavers with appropriate material. If using grass please use the specified rootzone material.Finished levels should be 5-7mm below the top of the cells. Do not overfill the grids. A lightvibrating plate can be used to consolidate the grids and to settle the rootzone infill if required.
- Rootzone must be free-draining structurally sound sand/compost or sand/soil blend. Normally this should be a propriety blend of 60:40 or 70;30 ratio.
- Sow seeds normally, fertilising and watering as required. A light top dressing may be applied to just cover the seed and to provide adequate germination conditions. Do not overfill the grids.
- The area to be reinforced should be marked out and excavated to the appropriate depth (se table). Depending on soil conditions and intended use of the area to be stabilised, dig out the existing base e.g. typically for light vehicle traffic / parking areas, 200- 300mm will suffice. With heavy wheel loads or a clay soil, 400mm may be necessary. Geo-textile membrane should first be laid on the earth before the base layer to create ground stability NB. Seek engineering advice where appropriate
- If using concrete edging pieces, install them next. If using R3 Products’ B-Gard install these between steps 4 and 5
- Compact the sub-base using a plate compactor. Fill the excavated area with free draining gravel or crushed stone to 100mm (grass) or 80mm (gravel) below the finished level. Tamp down with a roller or plate compactor.
- Level the area with a layer of fine aggregate or for grass sieve sand/compost/loam mix. Level using a rail or wooden batten and compact as shown in the diagram across. This is used to level out any imperfections or hollows within the surface of the sub-base, and if the area is to be grassed over, it provides an ideal environment for grass root survival and growth.
- If using R3 Products’ B-Gard to edge the area, install it at this stage. Once the whole area is completely level, you can proceed to interlock and lay the paving grids. They come pre-assembled in one square metre sections. Any that need cutting should be measured and cut prior to installation and where possible cut in such a way to leave complete cells along the outer edge. With the area completely laid and positioned correctly, the whole area can be lightly compacted ensuring that they remain flat and level.
- The area can then be back filled with the medium to be used. If using gravel, we recommend 10mm or less as this allows better filling of the chambers. If the area is to be grassed, we recommend using a 70/30 rootzone mixture which is essentially a mixture of quality topsoil and sharp sand. This prevents the hard compaction of topsoil alone which can limit grass growth. Initially the cells should be filled to approximately 10mm below the top surface, this will protect young seedlings during early establishment. The whole area can then be seeded and watered in.
Calculations for Quantities
Hardcore/Broken Stone required for the base layer
For cars = 300kg of hardcore/broken stone per m² (providing 150mm depth)
For trucks = 400kg of hardcore/broken stone per m² (providing 200mm depth)
Sand or Fine Chippings required for the leveling layer
For all grid types = 25kg of sharp sand (grass or gravel finish) or fine chippings (gravel finish only) per m²
Topsoil required for a grass surface (per m2)
For 40mm grid = 65kg of topsoil
Aggregate required for a graveled area (per m2)
For 40mm grid = 72kg of gravel