Lagos, the pulsating heart of Nigeria’s economy, is a city where dreams of grandeur meet the harsh realities of construction.
With over 20 million residents crammed into a landscape of reclaimed wetlands, sandy shores, and clay-heavy soils, building here is no small feat.
As a construction firm specializing in building construction, structural engineering, steel fabrication, and real estate development.
Kheymax Construct Limited has witnessed firsthand how the city’s unique challenges, intense urbanization, seasonal flooding, and variable soil conditions, can turn ambitious projects into costly nightmares.
Over the past decade, we have completed high-rise foundations in ikeja and residential rafts in Ikorodu, always prioritizing precision to avoid the pitfalls that plague so many builds.
Yet, despite these lessons, foundation failures remain alarmingly common.
According to reports from the Lagos State Building Control Agency (LASBCA), over 60% of building collapses in the state since 2015 trace back to subpar foundation work.
These aren’t just structural tragedies; they are financial disasters.
A single repair can balloon to ₦1 million or more, factoring in labor, materials, and downtime.
In this in-depth guide, we will unpack five of the most prevalent foundation mistakes we see in Lagos, why they happen, their devastating impacts, and most importantly, how to sidestep them.
Our goal? To empower you, the homeowner or developer, with knowledge that saves time, money, and lives.
Mistake number 1
Ignoring Soil Investigation and Site Specific Design
Lagos soil is as diverse as its people: loose sands in Victoria Island, expansive clays in Surulere, and peat filled marshes in Ajegunle.
Yet, a staggering 70% of new constructions skip a proper geotechnical survey, opting for generic designs copied from Abuja or Enugu blueprints.
This oversight assumes uniform ground conditions, but in reality, Lagos’ lagoon proximity and groundwater fluctuations demand tailored approaches.
Why it costs big
Without a soil test (which runs just ₦150,000–₦300,000), foundations settle unevenly.
In reclaimed areas like Lekki Phase 1, soft soils compress under load, causing differential settlement, cracks spiderweb across walls, doors jam, and entire structures tilt.
We have seen a 4 bedroom bungalow in Gbagada require ₦2.5 million in helical pile retrofitting after just two years, including evacuation and shoring costs.
A client in Ogba ignored our advice for borehole logging and went with a shallow strip foundation.
Monsoon rains triggered subsidence, leading to a ₦1.8 million fix involving soil stabilization with cement grout.
Prevention? Always commission a geotechnical report from certified engineers.
At Kheymax, we integrate dynamic cone penetration tests into every project, ensuring designs like deep pile foundations for high water table zones or mat (raft) systems for uniform load distribution.
Mistake 2
Skimping on Foundation Depth and Type
In the rush to cut corners, many builders opt for shallow pad or strip foundations (under 1.2 meters) even in flood-prone areas.
Lagos receives over 1,800mm of annual rainfall, exacerbating erosion and scour around inadequate depths.
Worse, in swampy outskirts like Ikorodu, ignoring deep driven piles leads to liquefaction during tremors or heavy traffic vibrations.
Why it costs big
Shallow foundations can’t resist uplift from buoyant groundwater or lateral forces from nearby excavations.
Repairs involve excavating and underpinning with mini-piles or jet grouting, clocking in at ₦1.2million to ₦3 million for a standard bungalow.
In extreme cases, like the 2023 Lekki collapse that claimed three lives, total demolition and rebuilds exceed ₦10 million.
A mid-rise apartment block in Yaba used 900mm-deep strips on clay soil.
Post construction flooding caused 150mm settlement, cracking the slab and compromising plumbing.
The fix? ₦1.5 million for resin injection and additional caissons.
We recommend depths of 1.5–2.5 meters minimum, with Franki piles for cohesionless sands or bored cast-in-situ for clays.
It’s an upfront investment adding 10–15% to foundation costs but it slashes long-term risks by 80%.
Mistake 3
Using Substandard Materials and Poor Compaction
The temptation to source cheap cement from unregulated markets or skip vibratory compaction is real, especially with material prices spiking 20% in 2025 due to naira volatility.
Inferior aggregates lead to weak concrete (compressive strength below 25MPa), while uncompacted backfill creates voids that water infiltrates.
Why it costs big
Weak mixes crumble under load, inviting heave in expansive soils or erosion in permeable sands.
Retrofitting demands jacketing columns with high-strength epoxy grouts, totaling ₦1Million to ₦2.2 million per floor level.
In Lagos’ humid climate, this accelerates corrosion of rebar, turning a ₦500,000 foundation into a ₦4 million liability.
An Ikoyi villa’s builder used under-cured concrete (28-day strength at 18MPa), leading to visible heaving after the first dry season.
We intervened with carbon fiber wrapping and void filling, costing the owner ₦1.7 million.
We source Grade 42.5R cement from Dangote or BUA, enforce 95% Proctor density compaction, and use admixtures for waterproofing.
This not only meets BS 8110 standards but extends foundation life by 50 years.
Mistake 4
Inadequate Drainage and Waterproofing
Lagos is synonymous with flooding, over 70% of the city lies below sea level, and blocked drains turn streets into rivers.
Yet, builders often neglect perimeter drains, sump pits, or bituminous membranes, assuming nature will handle it.
This invites hydrostatic pressure buildup, saturating soils and undermining footings.
Why it costs big
Waterlogged foundations swell and shrink cyclically, causing shear cracks and spalling.
Fixes like French drains and chemical injection run ₦800,000–₦1.5 million, but if mold or termite invasion follows, add ₦500,000 for remediation.
The 2024 Ajah floods saw dozens of homes with bowed walls, each repair averaging ₦2 million.
A Surulere duplex skipped DPC (damp-proof course) layers, resulting in rising damp that eroded the base.
Post-flood, capillary action pulled salts upward, delaminating plaster.
Our team installed crystalline waterproofing and gravel trenches for ₦1.3 million.
Prevention from Kheymax, we mandate 150mm wide perimeter drains sloped to outfalls, plus bentonite clay liners in high-risk zones.
It’s simple engineering that averts 90% of moisture-related failures.
Mistake 5: Cutting Corners on Professional Supervision and Permits
With a housing deficit of 20 million units nationwide, the pressure to speed up is immense.
Unlicensed contractors bypass LASBCA approvals, skipping third-party audits and load tests.
This leads to overloads from unplanned extensions or poor load paths from columns to footings.
Why it costs big
Unsupervised work hides defects like misaligned rebar or under-reinforced beams, only surfacing during occupancy.
Legal fines for unpermitted builds add ₦200,000–₦500,000, while structural audits and retrofits hit ₦1–₦4 million.
Building collapses in Lagos Island from 2018–2023 claimed 150 lives, often due to such negligence.
A client’s self-supervised mini-flat in Mushin overloaded its raft with a rooftop extension, causing 200mm deflection.
Stabilization with steel props and redesign cost ₦2.1 million, plus relocation fees.
We at Kheymax construct, we embed COREN-registered supervision from day one, securing permits in under 30 days.
Our steel fabrication expertise ensures precise load transfer, compliant with Eurocode 7.
These mistakes aren’t inevitable, they are avoidable with foresight.
Lagos’ growth demands resilient builds, and as urbanization pushes populations toward 30 million by 2030, the stakes are higher than ever.
Foundation failures don’t just drain wallets; they erode trust in our city’s future.
At Kheymax Construct Limited, we are committed to elevating standards.
With our track record in welding precision steel frames and engineering flood resistant foundations.
We have helped over 20 clients in Lagos avoid these pitfalls, delivering projects 20% under budget and on time.
Don’t let a shaky start undermine your vision.
Ready to build solid? Contact Kheymax Construct Limited today for a free site assessment and customized quote.
Call +2349164237270 or email info@kheymaxconstruction.com. Let’s construct excellence, your dream home awaits, unbreakable and affordable.