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🔧 Foundation Failures: What You Need to Know 🔧

Writer's picture: MTS DNC ENERGY CONSULTANTS LIMITEDMTS DNC ENERGY CONSULTANTS LIMITED

Updated: Jan 11

Learn about common causes of foundation failures, including settlement, subsidence, and heave. Discover symptoms, repair strategies, and the importance of thorough inspections in ensuring building safety and stability.
Foundation Cracks Caused by Settlement, Subsidence and Heave

Architects, surveyors, and structural engineers are often called upon to examine defective foundations and submit reports with recommendations for remedial action. While technical expertise plays a significant role, gut instinct, personal skill, and years of professional experience are equally important. After all, reviewing your 100th house brings insights that may have been missed on the first! 🏠


Causes of Foundation Failure:

Foundations can shift due to a variety of factors. One of the most common is settlement, where loads applied to the foundation cause downward movement. If the loads don't exceed the allowable bearing pressure set in the building codes, the structure can typically tolerate this. However, when subsidence occurs, often brought on by ground activity, the problems begin.


Common Causes of Subsidence:

  • 🌊 Soil erosion from flowing water.

  • 💧 Changes in groundwater levels.

  • 🏗️ Buildings constructed on made-up ground.

  • ⛏️ Movement from mining activities or shallow holes in chalk.

  • 🌳 Shrinkage or swelling of clay soils – the #1 cause of foundation movement!

  • Uneven bearing capacities between subsoils.


Heave: The Opposite of Settlement

Heave refers to the upward movement of the ground, typically caused by an increase in moisture levels. Common scenarios include:

  • 🌲 The removal of trees.

  • 💧 Interruption of natural watercourses due to climate change.

  • 🏠 Removal of loads on the foundation.

  • ❄️ Uncommon but possible: ground expansion during freezing conditions, particularly in fine sand and chalk soils during severe winters.

💡 While settlement, subsidence, and heave account for most foundation issues in low-rise buildings, other possible causes of damage must always be considered.


Common symptoms of foundation failure include:

  • Cracks in walls (hairline to wider gaps)

  • Bulging or leaning walls

  • Slanting floors

  • Blocked drains or malfunctioning pipes

  • Cracking in paving or driveways


Foundation Repairs: A Costly Endeavor

Repairs to existing buildings are often the most complex and expensive. This is why a thorough investigation is key. The goal? To determine the nature and strength of the subsoil under load. Here’s what goes into a proper foundation inspection:


  1. Trial holes are dug at intervals along the wall to expose the underside of the foundation.

  2. Subsoil details, foundation conditions, and the base of the wall are recorded.

  3. Tests include driving an iron bar into the subsoil, and more detailed moisture and bearing capacity tests with soil samples sent to a lab.


Know Your Soil:

Before any inspection, having precise knowledge of the soils on site is essential. Soil types range from hard rock to loose sand, with cohesive and non-cohesive soils having very different properties.

  • Non-cohesive soils: Gravel and sand – lack cohesion and have no plasticity.

  • Cohesive soils: Clay and silt – possess cohesion and plasticity.


🔍 A thorough investigation isn't just about what you see on the first visit. Foundation issues evolve over time, and it’s crucial to study the site carefully before making any decisions.


👉 When it comes to foundation problems, understanding the land beneath your building is half the battle. Don’t just rely on technical know-how – let experience guide your hand too.

Boost your knowledge and protect your structures from failure. Explore more about the foundations that keep your building strong!


Need Professional Help? Contact the Experts!

For Building Services Design – whether it’s HVAC, plumbing, or civil engineering – reach out to Nexus M&E Design for expert solutions tailored to your project needs.


If you require a technical assessment, BER rating, or assistance with SEAI grants, get in touch with the professionals at MTS DNC Energy Consultants for comprehensive guidance and support.


Disclaimer:

The content provided in this post is for informational purposes only and should not be construed as professional engineering, architectural, or surveying advice. While every effort is made to ensure the accuracy and reliability of the information presented, it is not a substitute for a thorough, site-specific inspection or the expertise of a qualified professional. For detailed guidance on foundation issues, structural integrity, or repairs, always consult with a licensed engineer, architect, or surveyor. The authors and publishers are not responsible for any damages or losses resulting from the use or reliance on this information.



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