If you have ever entered a house in Lagos and noticed wet patches on the wall, peeling paint, white salt-like stains, or that disturbing moldy smell, then you have seen rising damp at work.
Many Nigerian buildings, especially in coastal cities like Lagos suffer from dampness.
This is mostly because Lagos soil retains a lot of moisture, the water table is high, and houses are often built close together with poor drainage.
Unfortunately, once damp starts rising through the walls, repairs become expensive and sometimes require breaking floors and walls.
The good news is rising damp can be prevented completely through proper DPC installation, right planning, and good construction practices.
In this article, we’ll break down everything you need to know, in simple language whether you are building, renovating, or planning future construction.
What Is Rising Damp?
Rising damp is the upward movement of moisture from the ground into building walls and floors through capillary action.
In plain terms, water travels from the soil into your building through the blocks, plaster, and walls.
It starts from the ground floor and then slowly climbs upward, damaging the structure and making living conditions uncomfortable.
Common Signs of Rising Damp in Nigerian Homes
If you notice any of these, dampness is already attacking your building,wall paint peeling or bubbling, damp or wet patches on lower wall areas, rusty nails or metal around walls, warped wooden furniture or skirting, musty smell inside the home, mould or mildew growth, white, chalky stains (salt deposits),tiles or floor coating lifting.
The earlier you take action, the better, because rising damp spreads.
What Causes Rising Damp in Lagos Buildings?
Many houses experience dampness not because Lagos is coastal, but because builders skip important steps. Some common causes are
No DPC installed during construction
Wrong type of DPC or poor installation
Low ground level or building below road level
Poor site drainage and stagnant water
No damp-proof membrane under the floor
Using low-quality blocks that absorb water fastA lot of landlords ignore these during foundation and later spend millions on repairs.
Prevention is cheaper than cure.
What is DPC?
DPC (Damp Proof Course) is a material placed between the foundation and wall to block moisture movement. Think of it like an umbrella inside your wall, water will try to rise, but DPC stops it.In Nigeria, common types of DPC include:
DPC membrane (polythene sheet)
🔹 Bitumen felt
🔹 Liquid DPM coating
🔹 Chemical injection DPC
🔹 Torch-on membrane
But the effectiveness depends on proper installation, not just buying materials.
How to Install DPC Correctly in Lagos (Step-by-Step Guide)
- 1. Install DPM (Damp Proof Membrane) under the floor slab
Before casting the German floor, lay a 1000–1500 gauge polythene sheet across the entire floor surface.
Overlap joints by at least 150mm and tape them properly.
This alone prevents ground moisture from entering the building.
- Apply DPC at the right height above ground
DPC should be 150mm (6 inches) above finished ground level.
When blockwork reaches lintel height for DPC, use a membrane or bituminous layer across the whole wall thickness.
No gaps. No shortcuts.
- Ensure Continous DPC, no breaks
The DPC must run:
✔ Across the entire wall perimeter
✔ Under door openings
✔ Around corners
✔ Across block joints uniformly
If the membrane breaks or is punctured, water will find its way through.
- Use Quality Materials
Cheap membranes tear easily. Rising damp doesn’t care how much you saved.
Recommended for Lagos weather
High-density polythene (1.5mm thick)
Bitumen-based felt or torch-on membrane for premium projects
Liquid DPM + membrane combo for extra protection
This small upgrade saves your future repainting and repair costs.
- Build Proper Drainage System
Even if you install DPC well, poor drainage can still cause dampness.
Install perimeter drains
Proper gutter and run-off channels
Soakaways sized for Lagos rainfall
Floor level above road level where possible
Dry surroundings means long-lasting building.
- Use Good Quality Blocks
Blocks act like a sponge. The weaker they are, the faster moisture climbs.
At Kheymax Construct, we recommend:
1:6 mix for walls, vibrated blocks, solid blocks for wet areas, cheap blocks means future damp repairs.
How to Fix Rising Damp in an Existing House
If damp is already present, you can still solve it.
Solutions include
Chemical DPC injection into walls
Cutting and inserting DPC layers (advanced)
Applying waterproof membrane and plastering again
Installing perimeter drainage
Improving ventilation and dehumidification
Note: Some repairs require professional handling.
Why You Must Take Rising Damp Seriously
Ignoring rising damp leads to:
Structural weakness, health issues from mould, continuous repainting and repair cost, furniture and wardrobe damage, floor finishes lifting, property value drop
It’s cheaper to prevent than to repair later.
At Kheymax, we understand Lagos soil and coastal climate.
We don’t just build houses, we build them to last.
Our services include:
DPC installation and damp-proofing, Foundation and structural work, Complete building construction, Site inspection and technical consultation, Rising damp repair and treatment
Whether you’re building now or renovating, we can help you avoid future damp problems.
Conclusion
Rising damp is a silent destroyer. The best defence is proper DPC installation from day one.
Lagos weather is unforgiving, moisture will always try to rise, but with correct materials and workmanship, your building remains safe, dry, and durable.
If you are planning your project soon…
Don’t start building without a proper DPC plan.
Don’t allow damp to ruin your investment.
Contact Kheymax Construct Limited
For DPC, construction, or site inspection:
📞 Call/WhatsApp:
📍 Lagos, Nigeria
📧 Email:
We don’t just build structures —
we build homes that stand strong for generations.