Hiekkapohjalle

Hiekkapohjalle, or "sand foundation," refers to a type of base layer used in construction and landscaping, particularly in areas where a stable, level surface is needed for structures like sheds, small buildings, or pathways. The term originates from Finnish construction practices, where a layer of compacted sand serves as a foundational support beneath concrete slabs, pavers, or other ground-level installations.

The primary purpose of hiekkapohjalle is to provide drainage and stability. Unlike traditional concrete foundations, which rely on a solid base like gravel or crushed stone, sand acts as a permeable layer that allows excess water to drain away, preventing issues like frost heave or water pooling beneath structures. This makes it particularly useful in regions with seasonal frost or high water tables. The sand layer is typically 10–20 centimeters thick and is meticulously leveled and compacted to ensure uniformity.

In Finnish construction, hiekkapohjalle is often used for lightweight structures such as summer cottages (*mökki*), garden sheds, or small garages. It is also common in landscaping for patios, driveways, or walkways, where a stable yet flexible base is required. The method is cost-effective compared to deeper concrete foundations and reduces the risk of cracking due to soil movement.

Proper preparation involves removing vegetation, grading the ground, and spreading a uniform layer of sand. The sand is then compacted using machinery like plate compactors to achieve the desired density. While effective for certain applications, hiekkapohjalle is not suitable for heavy or permanent structures, as it lacks the load-bearing capacity of reinforced concrete.

In summary, hiekkapohjalle is a practical and efficient foundation solution for lightweight constructions and outdoor surfaces, offering durability and drainage in suitable conditions.