What foundations or groundwork does a pergola need?

A pergola’s front support posts must always be anchored to a solid foundation to keep the structure totally stable in high winds. Where it’s fixed to an existing solid concrete or paved base, posts can often be bolted down directly. In most cases on an existing patio the patio slabs are lifted where the posts are to go and a concrete pad is formed underneath the slab before placing back into position On softer ground or where no suitable base exists, we may need to form concrete footings (pads) for the posts to fix to. We assess the ground and confirm the required groundwork at the survey stage. Some models are offered with a mobile weighted base system usually consisting of a large steel box for each post filled with ballast and then either used as a planter or a seat with appropriate cover used to finish. Tis method gets around any potential issues with underground obstacles/cabling/drainage, etc. preventing pads being formed, but also defines the structure as temporary for some planning issues as it can be moved relatively easily if required.