An extension or conservatory that is subsiding

Why the extension in particular?

• The extension often stands on a shallower or lighter foundation than the main building
• The ground next to the house was once dug out and backfilled, and is less compacted
• A rainwater drain or sewer often runs just under the extension
• On clay, the ground at the edge dries out faster than under the house

How do you recognise it?

• A vertical or diagonal crack at the joint between house and extension
• A gap that is wider at the top than at the bottom, or the other way round
• Doors or sliding windows in the extension that stick
• A floor in the extension that slopes away from the house

How do we repair it?

We stabilise only the part that is sinking. Magnum Push Piers under the foundation of the extension carry the load down to firm ground. If the weak ground is shallow, Deep Lift strengthens the ground under the foundation with expanding resin, without digging. Where possible, we lift back in a controlled way.

First the cause

Have the drains checked by camera: a leak under or next to the extension is a common cause. If it is not fixed, the problem comes back.

With serious damage, have a structural engineer assess the situation. Soiltek is a specialist contractor: we record, measure, propose a technique and carry out the repair, in consultation with your engineer.