Why Roofs Develop Leaks During the Rainy Season in Togo

Every year, as the first heavy rains arrive across Togo between April and July, roofing contractors in Lomé and inland towns see a predictable spike in calls about leaks. Many of these problems were quietly developing for months during the dry season, only becoming obvious once sustained, heavy rainfall puts real pressure on a roof's weak points.

Understanding why leaks appear when they do, rather than treating each one as a surprise, helps homeowners and property managers catch the warning signs before the rains arrive and avoid the interior damage that comes with a roof failing mid-storm.

Corrugated Sheet Wear and Rust

Corrugated iron sheeting is the dominant roofing material across most of Togo, valued for its low cost and ease of installation, but it is also vulnerable to rust over time, particularly in coastal areas like Lomé where salt-laden air accelerates corrosion. Rust weakens the metal at fastening points first, and a sheet that looks intact from the ground may already have small perforations near its screws. During heavy rain, water finds these weak points and works its way through, often tracking along roof purlins before dripping somewhere well away from the actual hole, which makes leaks confusing to trace.

Poor Overlap and Fastening

Roofing sheets need sufficient overlap, both along their length and between adjacent sheets, to shed water effectively during Togo's often intense rainfall. Common installation shortcuts that cause leaks include:

• Insufficient side overlap between sheets, especially on lower-pitched roofs where water sits longer before draining.
• Fasteners installed without proper rubber washers, leaving small gaps that widen as the metal expands and contracts with heat.
• Missing or poorly sealed ridge caps at the roof's peak, a common entry point during wind-driven rain.
• Nails or screws that have loosened over years of thermal expansion, creating gaps that were not there when the roof was new.

Flashing and Junction Failures

Leaks concentrate disproportionately around roof penetrations and junctions, chimneys, water tank supports, and the points where a roof meets a wall or parapet. Flashing, the metal strip designed to seal these junctions, deteriorates faster than the main roof sheets because it often sits in standing water or shaded, damp conditions that encourage rust. Buildings with rooftop water tanks, common across Togo for managing inconsistent municipal supply, are particularly prone to leaks around the tank's support structure if the roof penetration was not properly sealed during installation.

The Cumulative Effect of Dry-Season Neglect

Many roof problems that surface in the rainy season actually began during the dry harmattan months, when dust accumulation, thermal expansion from intense heat, and minor pest activity around roof edges go unnoticed simply because there is no rain to reveal them. A roof inspection carried out in February or March, before the rains build, catches loose fasteners, early rust spots, and debris-clogged gutters while repairs are still simple and cheap, rather than waiting for a leak to appear mid-storm.

Frequently Asked Questions

Conclusion

Roof leaks during Togo's rainy season are almost always the result of small weaknesses that developed unnoticed over the preceding dry months, whether from rust, loosened fasteners, or failing flashing around penetrations. A proactive inspection before the rains arrive, focused on these known weak points, is far cheaper and less disruptive than dealing with an active leak once the storms have begun.