The first heavy rain of the year had just fallen in Benin City.

A homeowner called me early the next morning.

“Sir OJ, my new aluminium windows are leaking. Water entered my sitting room, soaked the curtains and damaged part of the POP ceiling. I thought aluminium windows don’t leak.”

When I got there, the problem wasn’t the aluminium window itself.

The problem was how it had been installed.

This is something we see more often than many people imagine.

Many homeowners believe that once they install aluminium windows, they never have to worry about water entering the house. Unfortunately, that’s not always true. Even expensive windows can leak if they are poorly installed, sealed incorrectly, or neglected over time.

If you’ve been asking, “Why are my windows leaking?”, you’re not alone. It’s one of the most common complaints we receive during the rainy season from homeowners in Benin City, Lagos, Abuja, Port Harcourt, Asaba, and many other parts of Nigeria.

The good news is that most window leaks can be fixed once you identify the real cause. In this guide, I’ll explain the most common reasons aluminium windows leak, how to identify the problem, and what you can do before the next rainfall damages your home.

Types of Aluminium Windows and Prices in Nigeria (2026 Guide)

Why Are My Windows Leaking?

Windows usually leak because of poor installation, damaged sealant, blocked drainage holes, poor wall finishing, incorrect window slope, worn rubber gaskets, or cracks around the window frame—not because the aluminium itself is faulty.

In our experience at OJ Aluminum, the aluminium profile is rarely the problem.

Most leaks happen because something around the window has failed.

Is It Really the Window?

One mistake many homeowners make is blaming the window immediately.

Sometimes the water is entering from somewhere completely different.

We’ve visited houses where the owner insisted the window was leaking.

After inspection, we discovered the water was actually coming from:

• A crack in the external wall
• A damaged roof flashing
• An unfinished concrete lintel
• A leaking gutter
• A cracked parapet wall

As water travels through tiny spaces, it may only appear around the window, making the window look guilty when it isn’t.

That’s why proper inspection matters.

Cost of Aluminum Windows in Benin City (2026 Price Guide)

11 Common Reasons Aluminium Windows Leak

1. Poor Installation

This is the number one cause.

A quality aluminium window installed badly will still leak.

At OJ Aluminum, we’ve been invited to repair windows installed by inexperienced workers. The homeowner assumed the manufacturer supplied bad windows, but the real problem was the installation.

Common installation mistakes include:

• Uneven frame alignment
• Wrong screw placement
• Poor frame support
• Large gaps around the frame
• Incorrect sealing

No matter how expensive your window is, poor installation can ruin its performance.

2. Damaged Silicone Sealant

Silicone is what prevents water from entering the gaps between the wall and the aluminium frame.

Over time, the sealant can:

• Crack
• Shrink
• Peel off
• Separate from the wall

This is common in Nigeria because of our intense sunshine followed by months of heavy rainfall.

During Harmattan, dust also settles around exposed joints, reducing the effectiveness of damaged sealants.

3. Blocked Drainage (Weep) Holes

Many people don’t even know aluminium windows are designed with drainage holes.

These tiny openings allow rainwater collected inside the frame to drain outside.

Unfortunately, they often become blocked by:

• Cement
• Paint
• Sand
• Dust
• Dead insects
• Leaves

When that happens, water has nowhere to go.

Instead, it begins to overflow into your room.

One of the easiest maintenance tasks is checking these drainage holes before every rainy season.

4. Poor Wall Finishing Around the Window

This is another problem we regularly see in Benin City.

Sometimes the window is perfect.

The problem is the wall around it.

If there are small gaps between the plaster and the aluminium frame, rainwater will find its way inside.

Remember this:

Water doesn’t need a big opening.

Even a tiny crack can allow surprising amounts of water into your home after hours of rainfall.

5. Worn-Out Rubber Gaskets

The rubber gasket is the soft material that helps seal the glass and movable parts of the window.

Over time it can:

• Become hard
• Crack
• Lose flexibility
• Shrink

Once that happens, water can pass through during windy rain.

This is more common in older buildings.

6. Poor Quality Accessories

Not every aluminium window accessory sold in the market is of good quality.

Cheap rollers, handles, locks and sealing strips often fail much earlier than expected.

Some installers focus only on reducing cost.

Unfortunately, the homeowner pays the price later.

At OJ Aluminum, we always explain that a good window is a combination of quality profiles, quality accessories and proper installation.

One weak component can affect the entire system.

7. Heavy Wind-Driven Rain

Sometimes your window isn’t defective at all.

Nigeria experiences storms where strong winds push rain directly against the window.

This is especially common in coastal cities like Lagos and Port Harcourt.

If the window wasn’t designed or installed to withstand wind-driven rain, water may penetrate weak points.

8. Cracks in the Wall

We’ve attended jobs where homeowners requested window replacement.

After inspection, we advised them not to replace the window.

Why?

The water was entering through cracks in the external wall above the window.

Replacing the window would have wasted their money without solving the problem.

Always identify the source before paying for repairs.

9. Poor Roofing Drainage

This surprises many homeowners.

Your leaking window may actually be a roofing problem.

When gutters overflow or roof water isn’t properly directed away from the building, large amounts of water flow down the walls.

Eventually, moisture finds weak points around the window frame.

10. Poor Maintenance

Like every part of a building, aluminium windows need occasional maintenance.

Ignoring small problems today often leads to bigger repairs tomorrow.

A quick inspection once or twice a year can help you discover loose sealants, blocked drainage holes and worn rubber before they become expensive problems.

11. Low-Quality Window Fabrication

Finally, not every aluminium fabricator follows the same standards.

Poor fabrication can result in:

• Poor frame joints
• Weak corners
• Incorrect drainage design
• Loose glazing
• Poor finishing

This is why choosing an experienced fabricator matters just as much as choosing the right materials.

How to Reduce Building Cost in Benin City (Practical Guide) 

How to Identify Where the Water Is Coming From

One thing I always tell homeowners is this:

Don’t rush to replace your windows just because you saw water inside your house.

First, find out exactly where the water is entering.

At OJ Aluminum, we’ve inspected homes where the owner had already bought new windows before calling us. After checking the building, we discovered the windows were fine. The real problem was a crack in the wall and a poorly installed roof gutter.

Before spending money, carry out these simple checks…

Check the Drainage (Weep) Holes

Open the window and look at the bottom part of the frame.

You should see small drainage holes.

If they are blocked with:

• Paint
• Cement
• Dust
• Sand
• Insects

the water may not drain properly.

Never seal these holes because they are designed to allow trapped water to escape.

Check the Wall Above the Window

Sometimes the leak starts much higher than the window itself.

During heavy rain, water can enter through cracks in:

• Plaster
• Concrete
• Window lintels
• Decorative mouldings

The water then travels down inside the wall before appearing around the window.

Observe the Leak During Rain

If possible, observe the window while it is raining.

Ask yourself:

• Does water appear only when there is strong wind?
• Does it leak only during heavy rain?
• Does it leak even after the rain has stopped?

The answers can help identify the real cause.

Can You Fix a Leaking Aluminium Window Yourself?

The answer is sometimes.

Small problems can be fixed without replacing the entire window.

For example:

• Cleaning blocked drainage holes
• Removing dirt around the frame
• Replacing damaged silicone
• Tightening loose screws
• Cleaning worn rubber seals

However, if the leak is caused by poor installation or structural problems, it is best to call an experienced aluminium fabricator.

Trying to fix major issues yourself may only make the problem worse.

How Much Are Sliding Windows in Nigeria? A Detailed Guide

When Should You Replace the Window?

Many people think every leaking window must be replaced.

That is not true.

In many cases, repairs are enough.

Replacement is usually necessary when:

• The aluminium frame is badly damaged
• The window has been poorly fabricated
• The frame is badly bent
• The glass system has failed completely
• Multiple repairs have not solved the problem

At OJ Aluminum, we always recommend repairs first if they will solve the issue. Replacing a good window unnecessarily is simply wasting money.

Common Mistakes Homeowners Make

Over the years, we’ve noticed the same mistakes repeatedly.

Waiting Too Long

Some people ignore a small leak because it only happens during heavy rain.

Months later, they discover:

• Damaged POP ceilings
• Swollen wooden furniture
• Peeling paint
• Damp walls
• Mould growth

A small leak can become a costly repair.

Choosing the Cheapest Installer

Everyone wants to save money.

But when it comes to aluminium windows, choosing the cheapest installer often becomes the most expensive decision.

Poor workmanship can lead to years of frustration.

Ignoring Maintenance

Even quality aluminium windows need occasional inspection.

Cleaning drainage holes and checking sealants once or twice a year can prevent many problems.

Covering the Leak Without Finding the Cause

Some people simply apply more silicone over everything.

That rarely solves the actual problem.

Always identify the source first.

Expert Tips from Osamuyimen Justice [OJ] – CEO OJ Aluminum Fabrication

After working on different residential and commercial projects across Benin City and surrounding areas, here are some practical tips I always share with clients.

Don’t Wait for the Rainy Season

Inspect your windows before the rains begin.

It is much easier to repair a small issue than deal with water damage later.

Quality Installation Is More Important Than Expensive Materials

I’ve seen affordable windows perform excellently because they were installed correctly.

I’ve also seen expensive windows leak because corners were cut during installation.

Don’t Ignore Small Cracks

Tiny wall cracks may look harmless.

Once the rains become heavy, they can allow surprising amounts of water into your home.

Keep Your Gutters Clean

Blocked gutters cause water to overflow down exterior walls, increasing the risk of leaks around windows.

Work with Experienced Professionals

A properly fabricated and professionally installed aluminium window should give you many years of reliable service.

Best Affordable Aluminium Windows in Nigeria for Every Budget

Myths vs Facts

Myth: Aluminium Windows Always Leak

Fact: Properly fabricated and correctly installed aluminium windows should not leak under normal conditions.

Myth: More Silicone Solves Every Leak

Fact: Silicone only works if the real source of the leak has been identified.

Myth: Every Leak Means You Need New Windows

Fact: Many leaks can be repaired without replacing the window.

Myth: All Aluminium Fabricators Produce the Same Quality

Fact: Experience, workmanship and quality materials make a huge difference.

Frequently Asked Questions

Why are my windows leaking only during heavy rain?

Heavy wind can force rain into weak points around the window, especially if there are damaged sealants or installation gaps.

Can leaking windows damage my house?

Yes.

Water leaks can damage paint, ceilings, walls, flooring, furniture and electrical fittings if left unattended.

How often should aluminium windows be inspected?

At least once or twice a year, especially before and after the rainy season.

Can blocked drainage holes cause leaks?

Yes.

Blocked drainage holes are one of the most common causes of water entering aluminium windows.

Can old silicone cause water leakage?

Absolutely.

As silicone ages, it can crack, shrink or separate from the wall.

Should I replace my window immediately?

Not always.

Many leaking windows only require professional repairs.

Why does my neighbour’s window not leak while mine does?

The difference is often the quality of installation, maintenance and finishing—not the window design itself.

Can poor roofing affect my windows?

Yes.

Overflowing gutters and poor roof drainage can direct large amounts of water toward your windows.

Final Thoughts

If you’ve been asking, “Why are my windows leaking?”, remember this: don’t assume the window itself is the problem.

In many cases, the leak is caused by poor installation, damaged sealants, blocked drainage holes, wall cracks, or roofing issues. The sooner you identify the real cause, the easier and less expensive it is to fix.

At OJ Aluminum, we’ve helped homeowners across Benin City and beyond solve window leakage problems without unnecessary replacements. Our goal is always to recommend the right solution—not the most expensive one.

A well-made and properly installed aluminium window should protect your home through heavy rain, Harmattan dust, and years of everyday use. Investing in quality workmanship today can save you significant repair costs in the future.

Call to Action

Is water entering your home through your aluminium windows?

Don’t wait until it damages your POP ceiling, paint, furniture, or walls.

Sir OJ and the OJ Aluminum team provide professional window inspections, repairs, replacements, and expert aluminium fabrication services in Benin City, Edo State, and other parts of Nigeria.

Whether you’re building a new home or fixing an existing one, we’ll help you identify the real cause of the leak and recommend the most effective solution.

Contact OJ Aluminum today for a professional inspection and let your windows keep the rain outside—where it belongs.