08 Jun Top 5 Mistakes to Avoid When Planning Piling or Underpinning Work
Piling and underpinning are specialist structural works that can protect a property, enable an extension, support a basement project, or solve serious foundation movement. But when these works are poorly planned, the consequences can be expensive, disruptive and risky.
Foundation issues are a major concern for UK property owners. The British Geological Survey states that shrinking and swelling ground, often reported as subsidence, is one of the most damaging geohazards in Britain today and has cost the economy an estimated £3 billion over the past decade. This is especially relevant for properties built on shrinkable clay soils, where changes in moisture levels can affect the stability of foundations and increase the need for specialist solutions such as underpinning or piling.
Here are the top five mistakes to avoid when planning piling or underpinning work.
1. Starting Work Without a Proper Site Investigation
One of the biggest mistakes is assuming that all ground conditions are the same. Soil type, groundwater levels, nearby trees, previous excavations, drainage defects and neighbouring structures can all affect the design of piling or underpinning. For example, clay-rich soils can shrink and swell as moisture levels change, which is one reason subsidence risk increases during dry and hot periods.
A proper site investigation helps determine the safest and most cost-effective solution. Without it, you risk choosing the wrong foundation method, underestimating costs, or discovering problems once work has already started.
2. Ignoring Early Signs of Structural Movement
Small cracks are easy to dismiss, but some can indicate more serious foundation movement. Warning signs may include diagonal cracks, cracks wider than 3mm, doors or windows sticking, uneven floors, or wallpaper tearing without signs of damp. Homeowners should seek professional advice if they notice signs such as sudden cracks, sticking doors and windows, or cracking that’s visible both internally and externally.
The longer structural movement is left unchecked, the more complicated and costly the repairs can become. Early assessment can help identify whether underpinning, piling, drainage repair, tree root management, or another solution is required.
3. Choosing the Cheapest Contractor Instead of a Specialist
Piling and underpinning are not general building tasks. They require technical knowledge, engineering input, specialist equipment and careful and precise planning.
Choosing a contractor based purely on price can lead to poor workmanship, inadequate temporary works, delays, or long-term structural problems. Safety is also a major consideration. The Health and Safety Executive (HSE) data shows that 35 construction workers were killed in work-related accidents in Great Britain in 2024/25, making construction one of the highest-risk sectors.
A specialist contractor will understand ground risk, structural loads, access constraints, insurance requirements and site safety from the outset. Choosing a specialist like U&M Group gives clients added confidence, as we have reliable accreditations including ASUC, Constructionline Gold membership, and CHAS, demonstrating strong quality, environmental and health and safety standards that are implemented in all our projects.
4. Failing to Consider Neighbours, Shared Walls and Access
Many piling and underpinning projects take place in tight residential or commercial settings, particularly in London and the Home Counties. Limited access, shared boundaries, adjoining structures and party wall matters can all affect the project.
Common oversights include:
- Not allowing enough time for Party Wall etc. Act notices
- Forgetting to assess vibration, noise and access restrictions
- Overlooking neighbouring foundations
- Failing to plan spoil removal and material deliveries
- Underestimating how basement, extension or structural repair works interact with existing buildings
Good planning helps avoid disputes, delays and redesigns once the project is underway.
5. Not Getting Expert Advice Early Enough
Many property owners only speak to a piling or underpinning specialist after cracks have worsened, planning has advanced, or a builder has already started work. By that stage, options may be more limited.
Early advice can help you understand the best technical approach, likely costs, project requirements and risks before committing to a design or construction route. At U&M Group, we provide specialist underpinning, piling, structural repair, basement construction and related services, with decades of experience in these areas. We have more than 40 years’ experience in underpinning and extensive piling expertise built over more than 30 years.
Plan Properly, Build Safely
Piling and underpinning work can add strength, stability and value to a property, but only when it is designed and delivered correctly. Avoiding these five mistakes can save time, money and stress while helping protect your building for the long term.
Need expert piling or underpinning advice? Contact U&M Group today for professional support with foundation solutions, structural repairs, piling, underpinning and basement works.