Void Formers

Void Formers protect concrete structures from damage caused by soil expansion. Joluka manufactures high-quality cardboard Void Formers that create a temporary buffer between the ground and the concrete. These formers collapse after construction, leaving a space that absorbs soil movement. This prevents upward pressure from cracking or shifting the concrete. Builders use them under slabs, beams, and foundations—especially in areas with clay-rich or expansive soils. The cardboard is wax-coated to resist moisture during the pour. Once exposed to water over time, it softens and disintegrates. This process leaves a void that allows the soil to expand without lifting the structure. Installation is simple. Workers place a layer of river sand after excavation. They wrap the Void Formers in plastic sheeting to delay moisture exposure. Then they position the formers before fixing steel reinforcement. Concrete is poured immediately after to ensure the formers stay intact during casting. They are lightweight, easy to handle, and quick to install. There’s no need to remove them after the pour. Joluka offers standard sizes from 100mm to 250mm in height, and can customise shapes and dimensions to suit any project. Proper storage is critical. Keep them dry and covered until use. Avoid exposing them to rain or humidity. Once placed, pour concrete without delay to prevent premature collapse. The product offers a reliable, cost-effective solution for managing soil movement. They help engineers and contractors build safer, longer-lasting structures in challenging ground conditions.