Foundation restoration that starts with understanding.
From first inspection to a stabilised foundation: we restore based on investigation and a structural design — never from a standard package.
Illustrative image
Every foundation tells a different story
Many Amsterdam buildings stand on timber piles in peat and clay, with groundwater as the main protector of that timber. When groundwater drops, loads change or the timber is attacked by bacteria, a building can settle unevenly. Which intervention makes sense differs per building and per façade. Below you can read what work we carry out and when it typically applies.
Foundation inspection and preliminary investigation
The basis for every decision: knowing what happens beneath the building.
- Visual survey of cracks, tilt and frames
- Coordinating inspection pits, timber samples and settlement monitoring with specialist firms
- Archive research into building drawings and earlier foundation reports
- Clear feedback: what we know, and what we don't yet
Pile and foundation beam replacement
New piles down to the bearing sand layer with a new concrete beam.
- Low-vibration pile systems suited to neighbouring buildings
- New reinforced concrete beam under the masonry
- Phased execution with temporary support
- Following the structural engineer's design
Column, beam and reinforcement repair
Targeted repair of concrete damage to columns and beams in basements or crawl spaces.
- Removing loose and degraded concrete
- Cleaning, treating or supplementing reinforcement
- New concrete jacket or repair mortar
- Element by element, supported where needed
Underpinning with steel tube piles
Transferring loads to new piles beside or beneath the existing foundation.
- Compact equipment, suitable for indoor spaces
- Steel or concrete needle beams for load transfer
- Possible per façade or part of a building
- Suitability depends on calculation and soil
Pile head lowering
Replacing the dried-out top section of piles so healthy timber is under water again.
- Requires timber quality investigation
- New extension in concrete or masonry
- Smaller intervention than full replacement
- Not suitable when bacterial decay spans the full length
Comparing methods
Which approach suits which situation?
A simplified overview to prepare the conversation with the structural engineer. The final choice always follows from investigation and calculation.
| Method | Often suits | Intrusiveness | Decisive factors |
|---|---|---|---|
| Full replacement | Widely degraded timber piles | High | Soil profile, neighbours, access |
| Underpinning | Local settlement, limited space | Medium | Bearing capacity, transfer structure |
| Pile head lowering | Dry timber, sound deeper down | Medium | Timber quality, groundwater level |
| Column and beam repair | Concrete damage, rebar corrosion | Low to medium | Extent of damage, support |
Intrusiveness is a general impression, not a prediction for your building. Combinations are common.
Engineering-led
How we arrive at the right method
- 1
Facts first
Measurements, inspection pits and timber research come before any price or method.
- 2
Designed by an engineer
Pile plan, beam calculation and phasing come from a structural engineer and form the basis for execution.
- 3
Buildable in the city
We test the design against narrow streets, quays, neighbours and the space around the building.
- 4
Checks per phase
Support, reinforcement and concrete work are checked per phase before we proceed.
Recognise
What foundation damage looks like
Foundation problems usually develop slowly. A single sign says little; a combination, or signs that get worse, is reason for investigation.
- 01
Stepped cracks
Cracks that follow the mortar joints, often diagonally from window and door corners. Cracks that widen matter more than hairline cracks in plaster.
- 02
Sticking windows and doors
Frames going out of square or doors that suddenly rub can indicate uneven settlement — but also damp or timber movement.
- 03
Leaning walls and sloping floors
A facade visibly leaning forward or sideways, or floors where a marble rolls away. A measurement turns a feeling into a fact.
- 04
Damaged columns and beams
Cracks, spalled concrete or rust stains on columns in a basement or crawl space. Exposed reinforcement calls for prompt assessment.
- 05
Separating joints
Gaps between facade and neighbouring building, between floor and skirting or at extensions can indicate differential settlement.
- 06
Damp and low groundwater
A dry crawl space that used to be wet can mean timber pile heads are now above the groundwater.
Amsterdam
Logistics in a historic city
Narrow streets, canals and closely built houses make execution in Amsterdam distinctive. Good preparation prevents delay and disruption.
- 01
Access and storage
Equipment and materials often need to be delivered in small quantities. Storage space on the street is limited.
- 02
Parking and closures
Site set-up, skips or temporary closures may require municipal permission. Costs and conditions are set by the municipality.
- 03
Working from inside
Where there is no space outside, work is sometimes done from inside with compact, low-vibration equipment. That requires cleared rooms.
- 04
Neighbours and block approach
Buildings often share foundations. Restoring per block can have structural and logistical benefits, but requires coordination.
- 05
Living in during works
Whether you can stay depends on the method. When working from inside, temporary housing is often needed.
- 06
Monuments and protected areas
Additional requirements apply to listed buildings. Coordination with the municipality is then especially important.
The information on this page is general in nature and not structural or legal advice. Suitable advice can only be given after investigating your specific situation.
Conceptual illustration
Stage 7 of 7New load pathThe extension carries its load through beam and piles to the sand layer; the existing house keeps its own load path.
Home extension
Foundation for a home extension
An extension adds new load to the ground. Whether it is carried by its own foundation, a connection or a combination is decided by the structural engineer, based on soil investigation, the existing foundation and permit requirements.
Simplified illustration, not a design. Foundation type, pile depth and the connection to the existing building follow from the structural design, soil investigation and the permit.
Concerned about your foundation?
Describe your situation and optionally add photos or drawings. We'll contact you to discuss the next steps.