Placing a heavy stone bench directly on grass is a recipe for wobbling, sinking, and an uneven seat. To create a stable, permanent, and level foundation, you need to interrupt direct contact with the soil. The best and most common solution is to use a solid, level base.
For ultimate stability, set your bench on concrete patio slabs or paving stones. First, mark the area where the bench legs will sit. Excavate the turf and soil to a depth of about 4-6 inches, making the hole slightly larger than your slab. Fill the bottom with 2-3 inches of compacted gravel or crushed stone for drainage. Then, add a layer of sharp sand, level it meticulously, and set your slab on top. Use a spirit level to ensure it's perfectly flat. The slab distributes the bench's weight over a wider area, preventing sinking.
A gravel and sand base is another excellent, permeable option. Excavate a wider area for all legs together or individual holes for each leg. Aim for a 6-inch depth. Fill with 4 inches of compacted gravel, topped with 2 inches of leveled sand. Tamp the sand firmly before positioning the bench. This method provides superb drainage and stability.
Crucial tips: Always check for level both front-to-back and side-to-side before finalizing. If your ground slopes, you may need to dig deeper on the higher side to create a level base. For extra security on slopes, consider setting the slabs in a shallow bed of mortar. This small investment in a proper foundation prevents future headaches, ensuring your beautiful stone bench remains a solid and welcoming garden feature for years to come.