What underpinning covers
Underpinning extends an existing foundation deeper or strengthens it, either because it has settled or because the ground beneath is being lowered. It is carried out in short alternating sections so the building is never left unsupported, and it is always designed by an engineer.
Underpinning extends an existing foundation deeper or strengthens it, either because it has settled or because the ground beneath is being lowered. It is carried out in short alternating sections so the building is never left unsupported, and it is always designed by an engineer.
Deepening or strengthening an existing foundation, worked in short sections to engineer design.
Waystar carries out this work on residential and commercial property in Brooklyn and across New York City. Every project starts with a look at the building, and the scope, the materials and the figures are written down before anything begins.
When might you need it?
These are the signs owners usually notice first.
- A foundation that has settled and needs support at greater depth
- A basement floor being lowered below the existing footing
- Adjacent excavation undermining an existing foundation
- Inadequate original foundation depth for current loads
- Movement continuing after other repairs have been tried
What the work involves
- Engineer design and sequence obtained before any work
- Monitoring installed to record movement during the works
- Excavation in short alternating sections to the design
- New foundation cast beneath the existing footing
- Pinning between new and existing work to transfer load
- Sections completed in the specified order until continuous
How the process works
Work to the engineer sequence
Section length and order are design decisions that keep the building standing.
Set up monitoring
Movement is recorded through the works so any change is caught immediately.
Excavate and cast in sections
Short alternating bays, each completed before adjacent ones open.
Pin and continue
Each bay is pinned to the existing footing and the sequence continues until complete.
What you get
- The building supported at every stage of the sequence
- Movement monitored throughout rather than assumed
- Work carried out to a designed sequence, not an approximation
What affects the scope
- Depth required and the length of foundation to be underpinned
- Ground and water conditions at depth
- Proximity of neighbouring buildings and any notices required
- Access for excavation and concrete placement
This is a preliminary planning range, not a quote. A property visit is required before any price is confirmed.
Frequently asked questions
Is underpinning disruptive?
Yes, genuinely. It is noisy, it takes time because of the sequencing, and it usually involves working inside as well as outside.
Can it be done in one go?
No. Working in short alternating sections is what keeps the building supported. Continuous excavation would remove its support.
Do neighbours need to be told?
Where work is near a shared or neighbouring structure, notice is usually required. It is identified early rather than raised once work starts.
Services often needed alongside this
This service is part of Structural and Concrete Work.