Why is my roof leaking?

Roofs have one job – to keep your home safe from the elements. But while the job description is simple, the task is much more complicated. Roof leaks can stem from a wide variety of problems – some caused by damage, some by age, and some even by misuse.

In this article we’ll look at the most common sources of roof leaks and offer some advice on how to minimize their possibility in the future. If your roof is currently leaking, one of the following problems may be at fault – but you should have a professional roofer take a look because diagnosis can be tricky and problems can quickly worsen!


An old roof

An old roof isn’t necessarily a leaky roof – however the two often go hand in hand. Over the years, roof systems are exposed to thousands of heating and cooling cycles, the withering gaze of the sun, pounding rains, and driving winds. Eventually, something gives – a nail pops up, a board rots or warps, asphalt shingles begin to crack – and then leaks begin to happen.

The occasional leak is not itself a sign of concern, but if you are frequently making service calls to your roofer to fix minor leaks, then your roof may simply be at the end of its life and in need of replacement.

Cracked or corroded roof flashing

Roof flashing is made up of thin sheets of metal used to prevent water from entering into your home and is found along boundaries where your roof meets walls or chimneys. Generally, the material used for flashing is a thin, flexible metal like copper, aluminum, or galvanized steel, and as these materials age they can become brittle or corrode leading to failure.

In some cases homeowners may be able to inspect flashing on their own, but for steep roofs or hard to access areas your best option is to have a professional roofing contractor perform annual inspections to monitor for signs of damage.


Cracked roof vent booting

Modern roofing systems often incorporate one or more roof vents. These vents serve a variety of purposes including ventilating your attic and serving as an outlet to bathroom or kitchen hood fans. The vent itself is very rarely the culprit of leaks, but instead the blame often lies with the boot surrounding it.

When working properly, a roof vent boot allows the vent to protrude through your roof while making a waterproof seal. However, over time the boot material can corrode, crack, or otherwise fail. Vent boot failure can occur due to chronic material fatigue which leads to cracks. Old vent boots also tend to be more brittle and thus more likely to be damaged by high winds or falling debris.

Skylight leaks

The benefits of skylights are hard to deny – they provide free, natural light in your home and look great. However, every hole in your roof is an opportunity for leaks – and skylights have a notorious reputation for being the culprit of roof leakage!

The caulks and sealants laid down around the edges of your skylight may dry out or crack over time – allowing water to enter your home. Homeowners with skylights are advised to pay particular attention to these attractive but risky features and should have them checked out at each roof inspection.


Gutter build up

One of the most common causes of roof leaks isn’t actually related to roof damage at all! Your home’s gutters and downspouts are tasked with channeling water away from your home’s foundation, but over time they can become clogged with fallen leaves or pine needles.

When gutters become clogged the water simply spills over top, creating the possibility of the water flowing into your attic or walls. These leaks can be hard to detect as the water damage may be initially hidden entirely within your wall cavities. Only after mold and mildew have taken hold will the problem become obvious – but by this point the damage will be severe.

It is essential to keep your gutters in good condition – routinely cleaning them out to keep them flowing smoothly.

Damaged or missing shingles

If you ever notice that a shingle has been damaged or has gone missing you need to call your roofer ASAP! Damaged and missing shingles can lead to disastrous leaks if not addressed quickly. Newer roofs tend to be less susceptible to shingle damage as the shingles are more resilient when they’re new – but wind-blown debris can damage shingles of any age.

Chimney damage

Just like roof vents and skylights, your chimney is essentially a hole in your roof that was deemed worth the risk. While generally quite durable, chimneys can get damaged by water intrusion, excessively hot fires, or even foundation settling. No matter the cause, a crack in your chimney can lead to water entering your home and needs to be addressed promptly.


Weather damage

Mother nature can be fierce with high winds throwing tree limbs against your roof and in some cases even scouring the shingles from your roof! Other threats, like hail, are less common, but can be even more devastating – possibly destroying your roof in the span of a single afternoon storm.

New roofs stand the best chance of surviving intense weather events, but no matter the age of your roof a major storm can cause serious damage. After severe storms, homeowners should visually inspect their roofs from the ground (or any windows that happen to look out onto their roof) and assess for damage.

Many high end roofing systems, like GAF shingle roofs, come with warranties that cover weather-related damage. If you suspect your roof has been damaged in a recent storm you should have a reputable roofing company come out and assess. Detecting damage early is important, as this is the best way to prevent further damage from taking place.


Attic condensation

One of the stranger sources of leaking roofs actually comes from inside your home. If your attic is improperly ventilated or insulated, condensation can form on the underside of your roof and then drip into your home.

Condensation can lead to mold, mildew, and rotting timbers in your attic, and can even become severe enough to cause you to need a complete roof replacement. Just like many other common roofing problems, it is vital to act quickly as delaying repairs may result in much greater consequences.

Improperly sealed valleys

Roof valleys are just like geological valleys – they are the low point between two peaks. As the low point, they experience a lot of water flow during heavy rains and are thus susceptible to leaks.

Your roof’s valleys use a special type of flashing which, depending on the installation method, may or may not be visible above your shingles. If this flashing becomes damaged or degraded over time then you may begin to experience leaks.

Repairing or replacing roof valley flashing is a big job and should only be done by qualified professionals. Keep in mind that if you need to walk on your roof, you should avoid stepping in the valleys as this can cause damage to the valley flashing.


Excessive use

This is an unusual cause of roof leaks – but is definitely something to be aware of. Ultimately, roofs aren’t meant to be walked on – at least not often! If you (or perhaps more likely, your children) enjoy getting up onto the roof to hang out, then you are risking damage.

Many parts of your roof, such as valleys, flashing, boots, and roof caps, should never be stepped on. Whenever you do need to walk on your roof, use extreme care both for your own safety, and for your roofs!

No Matter The Roof Issue – You Should Act Fast

While the source of the leak may vary – the reality is that all roof leaks need to be treated quickly before the problem worsens. A minor leak will ultimately lead to major problems like mold and rotting wood and what was initially an easy repair may transform into an entire roof replacement!

If you think you have a roof leak, contact a reputable, local roofing company and get it fixed as quickly as possible. When kept in good condition roofs can last decades – just remember to stay on top of maintenance and don’t defer necessary repairs!