The Plastic Pro Base is a lightweight and eco-friendly alternative to a concrete base and allows you to create a custom base quickly and easily. The base is perfect for sheds, summer houses, green houses, log cabins and playhouses, allowing you to create a firm and level base and raise your buildings to prevent damp. The included membrane allows water to drain away while preventing weeds and other harmful elements from damaging the underside of you garden building. Each of the 500mm grids easily interlock to create a solid and rigid construction. Due to the strength of the plastic and the construction of the Pro Base, it is strong enough to carry the load of a small garden shed without the need for pea gravel. Each grid can hold approximately 10kg of 10mm round pea gravel. The gravel also helps with weight distribution on larger buildings.