Rainy Season Home Maintenance Checklist for Lagos Homeowners

TL;DR: In Lagos, rainy season damage rarely starts with the storm itself. It starts months earlier with a blocked gutter, a hairline crack in a flat roof, or a drain choked with sand. Work through roof, drainage, walls, septic and power checks before the heaviest rain, and repeat the drainage checks monthly while it rains.

I have walked into too many houses in Lekki Phase 1, Ajah and Magodo in August where the ceiling was already stained brown and the owner was asking for a quick paint fix. Paint is never the fix. The water found a way in weeks before the stain appeared. This checklist is how I tell homeowners to stay ahead of it.

1. Roof first — while you can still get on it safely

Do this in the dry window before the rain sets in properly, not during a downpour.

For pitched roofs in Lagos, I look for slipped or cracked aluminium and stone-coated sheets, rusted nails working loose, and valleys filled with leaves and sand. On flat roofs, which are common on newer duplexes in Ikate, Agungi and Osapa London, the killer is ponding — water sitting for days because the fall to the outlet is wrong. Ponding adds weight and finds every pinhole in the membrane.

Get a roofer to check flashing around water tanks, solar panels and generator exhausts. Those penetrations leak first. Inside, check ceilings and the top corners of wardrobes for faint rings or bubbling paint. That is your early warning.

Do not let anyone seal a wet roof and call it done. The surface needs to be dry, the failed section cut out and replaced, and the fall corrected where water pools.

2. Gutters, downpipes and compound drainage

A blocked gutter in Lagos does not just overflow. It dumps water down your external wall, feeds rising damp at the base, and floods the compound because the discharge was never connected properly.

Clear gutters and downpipes, then watch them in the first heavy rain. Water should leave the compound through a proper channel to the street drain. In many estates in Sangotedo, Abraham Adesanya and VGC, the street drain itself is half-full of sand and pure-water sachets by June. Clear the section in front of your gate. It is not glamorous, but it stops water backing up into your compound.

Check the gradient of your interlocking. If rain runs toward the house instead of away from it, you will get damp skirting and mould inside no matter how good the roof is. In low-lying parts of Lekki and Ajah, raise vulnerable thresholds and keep a sandbag or flood board option ready for the worst nights, rather than improvising at midnight.

3. Walls, rising damp and mould control

Rising damp shows as tide marks, peeling paint up to about a metre high, and a musty smell that returns after cleaning. In Lagos it is usually driven by a failed or missing damp-proof course, cracked external render, or soil and interlocking built up too high against the wall so they bridge the damp-proof line.

Scrape back failed paint only after you have fixed the source. Check external walls for cracks, especially around window frames in Surulere, Yaba and older Ikoyi houses where movement has opened joints. Seal, re-render where needed, and keep air bricks and vents unblocked. I still see vents plastered over during renovations in Ikeja GRA. That traps moisture and guarantees mould in the room behind it.

Inside, mould loves wardrobes against external walls, bathrooms with no extractor, and rooms kept shut while the house is empty. Leave a small gap between furniture and external walls, run bathroom fans, and open windows when the rain eases. Clean early mould promptly and fix the leak behind it, or it will return within weeks.

4. Septic, soakaway and water systems

Rainy season is when weak septic systems announce themselves. If your soakaway is already struggling, extra groundwater leaves nowhere for effluent to go. Watch for slow drains, gurgling toilets and odour after heavy rain in houses in Ajah, Badore and older estates in Festac.

Arrange desludging before the system is full, and keep heavy vehicles off the septic cover. Check borehole surroundings too. The apron around the borehole should be intact and raised so contaminated surface water cannot run straight into the casing during flooding. If floodwater covers the borehole head, do not drink from it until it has been checked and treated.

For stored water, clean overhead tanks at least before and after the rainy peak. Algae and sediment build faster when roofs are washing dust and leaves into gutters for months.

5. Fences, retaining walls and trees

I pay special attention to fences and retaining walls in hilly or waterlogged plots, and anywhere soil is held back above compound level. Look for bulging, leaning, new diagonal cracks and weep holes that are blocked. A wall holding back saturated soil carries far more load in August than in January.

Cut back branches overhanging the roof before the windy storms. In older parts of Ikoyi and Ikeja, mature trees drop heavy limbs on aluminium roofs every season. Clear leaves off the roof after storms too. Wet leaf mats trap moisture and accelerate rust at fixings.

6. Generator house, electrics and safety

Generator houses flood quietly. Check that the generator sits on a raised plinth, the exhaust cannot let rain back in, and fuel is stored so floodwater cannot spread it. Never run a generator in standing water, and get an electrician to check external sockets, changeover switches and earthing before the season. Water and tired wiring are a dangerous mix.

Test your inverter and batteries as well. Rainy season brings more outages in many areas, and a battery that was fine in March may not carry the house through a wet night in July.

A simple rhythm that works

Before the rains: roofer, gutter and drain clearing, external crack repairs, septic check, tree cutting, electrician visit.

During the rains: monthly drain and gutter checks, walk the compound after heavy rain to see where water actually goes, and act on ceiling stains within days, not months.

After the rains: repaint only where the source is fixed, service the borehole and tanks, and note every repair for next year. In my experience, the homeowners who keep that note spend far less than those who repaint the same wall each December.

Frequently asked questions

When does rainy season start in Lagos and when should I do maintenance?

The heaviest rain usually falls between June and September, with rain starting earlier in the year. Do roof and drainage work in the dry months before that peak. Keep clearing drains monthly while it rains, because sand and leaves rebuild fast.

How do I stop rising damp in my Lagos house?

Fix the source first: blocked drainage, soil or interlocking bridging the damp-proof course, cracked render, or a leaking pipe. Then repair the wall and allow it to dry before repainting. Painting over active damp without fixing drainage or the damp-proof line will fail within one rainy season.

Why is there mould in my wardrobe during rainy season?

Warm, still air against a cold external wall creates condensation, and a small roof or render leak makes it worse. Move the wardrobe slightly off the wall, improve ventilation, and check the external wall and ceiling above for leaks. Clean the mould and monitor it — rapid return means water is still entering.

What should I check after heavy rain floods my street in Lekki or Ajah?

Check that floodwater has not entered the borehole head, septic cover or generator house, and photograph any water lines for your records. Clear the drain in front of your gate once water drops. If water entered the house, dry it quickly and watch for mould in skirting and wardrobes over the next two weeks.

Should I repaint immediately after a leak?

No. Find and fix the leak, let the plaster dry properly, then prepare and repaint. Painting a damp wall traps moisture and the paint will bubble and peel. A stain that keeps growing after rain means the leak is still active and needs a roofer, not a painter.

Related reading: Renting in Rainy Season: 12 Checks Before You Pay Related reading: How to Flood-Proof a House in Lagos: Costs & Fixes Related reading: Living in Lekki During Rainy Season: Street-Level Truth