Pile Head

Summary

Pile Head - A pile head is an enlarged concrete section constructed over the top of a pile which helps spread the supporting force that the pile exerts on the structure it is holding.

Technical Information

For concrete floor slabs, pile heads are very important additions to piles as they help to reduce the maximum bending moment experienced by the slab, by reducing the effective span. They also reduce the chance of the slab failing by punching shear from the pile.

A well constructed pile head should be level and have a smooth trowelled finish. According to TR34, the pile head’s level tolerance should be no greater than +0, -25mm with respect to the slab soffit and its slope should be no greater than 5mm over its width. Also, the head must not project above the sub-base.

If a pile head is poorly constructed, it could cause restraint to the slab which is laid on top of it. This is to be avoided at all costs as piled supported slabs are usually steel fibre reinforced and ‘jointless’ so any cracks that propagate to the full depth of the slab could potentially have serious structural implications. To help minimise restraint on the slab from the pile head, an additional layer of slip membrane must be laid directly over, extending 300mm past the edge of the pile head in each direction.