Why Does A Roof Leak? Here’s 19 Reasons Why…

You may install a roof to your property which looks great and provides a good protection from various external elements. But after a while, it may lose its integrity, and may cause issues for different reasons. So if you are asking yourself – why does a roof leak?

Here’s a rundown of the most common reasons.

why does a roof leak
Example of a leaked roof. Source: Flickr

Aged Roofing Materials

A common reason for a roof leak is old, deteriorated or damaged materials. The roof of your home is one of the most important parts of it and its longevity depends on how well you maintain it. Roofing materials can be damaged by extreme temperatures over time, as well as severe weather such as rain, snow and hail. 

When roofs are exposed to these elements over an extended period of time they can begin to deteriorate or break down which will lead to issues down the line.

There are various factors that cause a roof leak including old or damaged materials such as shingles or flashings (the metal foil that covers joints between two pieces of shingles). 

Faulty or damaged flashing

Another reason for leaks could be poor installation practices during construction; improper flashing installation means water will eventually find its way into your home through small gaps in your roof’s protection system where there should never be any holes at all!

Flashing is a small piece of metal that is used to seal the gap between the roof and the wall. Flashing can be damaged or missing, which then allows water to seep into your home. It can also be replaced or repaired by a professional roofer in order to prevent further damage.

Broken or Missing Roof Tiles or Slates

A leaky roof can be a major problem, as they can cause damage to the interior of your property and even lead to further problems if left untreated. It’s therefore important that you check for broken or missing tiles or slates when inspecting your property for leaks. If you notice that any of the tiles on your roof are broken or missing, it is advisable to have them replaced immediately by a professional contractor.

The easiest way to check if any tiles are missing from your roof is by looking at it from ground level. If you cannot see any gaps in between the slates then this is an indication that everything is intact and there are no missing items on the surface of your home’s exterior walls.

Damaged Roofing Membranes or Underlay

Roofing membranes are the primary layer of protection for your roof. They’re designed to protect the roofing materials from the elements, and they also serve as a barrier between your home and water damage.

Underlayment is sometimes used instead of a membrane to protect against weathering effects, such as wind-blown rain or heavy snow loads.

If either of these components are damaged or torn in any way, they can leave your roof vulnerable to leaks and damage that could turn into major problems down the road.

Using the Wrong Roofing Materials for Your Roof’s Pitch

Why does a roof leak that has a low pitch? Well, this is a common problem because it’s steeply angled. The steeper the pitch, the more water will pool in your gutters and have nowhere to go but down.

Not all materials are created equal when it comes to handling low pitches. For example, you can’t use asphalt shingles on a 7 inch roof because they won’t last as long on such a steep slope—and the same goes for metal roofs like standing seam metal or corrugated metals.

Poorly Placed Fixings

Sometimes, it’s the fixings themselves that are to blame. Roof tiles and slates are laid on top of a framework of wooden battens, which are then fixed to the roof with screws or nails. If these fixings aren’t placed correctly—for example, if they’re not centred over the tile/slate or if there are one too many holes around the edge—they can cause water to leak into your home. To stop this from happening:

  • Make sure all screws and nails are driven into the batten at least 1″ from where it meets other pieces of wood (the closer you get to an edge, the higher risk there is for leakage).
  • Fix any damaged parts carefully using a pair of pliers and seal any holes left behind with silicone caulk before re-fixing.

Condensation In Your Loft Space

There are two types of condensation; interstitial condensation and surface condensation.

Condensation is usually caused by high humidity, which can be caused by a number of factors. The first culprit is the installation of an under-ventilated roof system. This means that there are gaps or voids in your attic insulation that allow for moisture to build up and cause problems. If you suspect this may be the case with your attic, have it inspected by a professional as soon as possible!

Another common reason for condensation is a lack of airflow—or air exchange—in your home’s ventilation system. To fix this problem, you’ll need to install adequate roof ventilation; otherwise, your house will retain moisture and could get mouldy.

Poorly Installed Skylights or Roof Windows

One of the most common reasons why a roof leaks is due to poorly installed skylights or roof windows. These structures are often subject to poor workmanship—or just bad design and installation—and can be damaged by storms, ice accumulation and other hazards.

Clogged Gutters

Clogged gutters are a common culprit for roof leaks. If you have gutters attached to your home, they should be cleaned regularly. The best time to clean them is before leaves start falling in the fall and after heavy rains or storms.

When leaves land in your gutter, they can become lodged there, causing water to pool and leak into the house instead of draining away from it through the downspout (a pipe that takes water from your roof).

Cracked Chimney

If you have an older home, chances are that your chimney has never been cleaned. As a result, it may be filled with years of creosote and other debris that has built up over the years. This can cause condensation to form within the flue structure itself, leading to leaks in roofing materials and ceilings below.

Make sure that your chimney is being swept regularly so that all of this debris can be removed from inside—and ensure that it’s inspected annually by a professional so they can make sure there aren’t any cracks or other structural issues developing. If you find any problems with your chimney, get them repaired or replaced as necessary!

Ice Damming

If you are wondering why does a roof leak during winter? It may be that you have ice dams. Ice dams are formed when snow on your roof melts due to the warmth of the home below, then refreezes as it reaches the edges. As more snow melts and refreezes, an ice dam can form. This can cause water to seep into your attic and leak through ceiling tiles or walls. Fortunately, there are several things you can do to prevent ice dams:

  • Use a roof rake to safely drag snow off of your roof before it turns into an icicle-filled mess that could damage your home’s exterior or interior structure by breaking off during windy conditions.
  • Inspect gutters regularly and clear them if they’re clogged with debris like leaves or pine needles (which tend not only to plug drains but also attract rodents who live in them).

Damaged Roof Vents

Roof vents may seem like a small, insignificant part of your home’s overall structure, but they are actually vital to its longevity. Venting allows air to flow in and out of your home so that no moisture gets trapped and causes damage. So if you notice any cracks in your roof vents, it’s time for some repairs!

Damaged roof vents can be caused by ice or snow build up on top of them during the winter months. The weight of this can cause severe damage to the vent itself – sometimes even causing leaks! 

In addition to damaged vent covers from ice or snow, damaged roofs can also impact your venting system as well. 

If you’ve experienced any sort of leak near where your ventilation system is located then this could be a sign that there’s something wrong with either one (or both) parts of unrelated issues such as loose nails which may need addressing before there’s any further damage done.

Damaged Soffit or Fascia Boards

When it comes to the exterior of your home, there are a number of factors that can cause water damage. One of the most common ways for this damage to occur is through soffit and fascia boards. 

These boards run along the bottom edge of your roof and are typically made from wood, aluminium or vinyl. They’re used to protect walls from rainwater leaks as well as insulation from melting during extreme heat or cold conditions such as those experienced in winter months.

However, these boards are often damaged by high winds during storms or ice buildup during freezing temperatures in winter months.

Roof valleys are poorly sealed

Are you wondering why does a roof leak in valleys? A valley is a low point of a roof that has two slopes coming together to form an opening between the two slopes. The most common causes of leaks in valleys are poor sealing and leaks around flashing.

The best way to prevent water from seeping into your attic is with durable, quality sealing materials like asphalt-impregnated felt or rubber membranes such as EPDM roofs, which protect your home from moisture damage and rot. 

When choosing which type of sealant to use in your home’s valley, consider whether you live in an area with high winds or heavy rainfall (both elements will increase the likelihood of leaks). 

For example, if there’s evidence that water has previously leaked through this area of your house then choose a more durable option such as hot asphalt since it will last longer than traditional roofing felt (which tends to deteriorate over time). 

If you’re unsure what material would work best underneath your current shingles then consult an expert before making any changes so they can determine which type would be safest for both parties involved.

Working on Your Roof

In order to avoid roof leaks, you should never work on a roof when it is wet or raining. You should also make sure that the ladder that you are using is stable and tall enough for the job. There are other safety measures that you should take as well:

  • Don’t stand on top of your ladder.
  • Don’t use an aluminium ladder on a metal roof because they don’t conduct electricity like wood ladders do.


Birds, squirrels and raccoons are generally pretty harmless to your roof. However, if they find a way to settle on the roof for a long time, they can cause damage. You could be vigilant to keep them off, then this shouldn’t be an issue for you.

One trick is to use netting or netting-type material around the perimeter of your home so that when they get up high enough on the side of a house they’ll fall back down before making it over to the roof line. You might have success with this method alone in preventing wildlife from getting up there in the first place too!

Overhanging Trees

Overhanging trees can cause significant damage to your roof. This can include structural damage to the roof, damage to the insulation, and even damage to your roofing materials.

It also means that you may need to replace any other parts of your home that were damaged because of this leak, such as gutters or fascia boards.

Lean-To Roof

If your roof is sloping on one side only and not the other, then it’s a lean-to roof. These types of roofs are often used to extend the living space of a property or house by creating an extension. They’re also useful for creating an independent living space on the ground floor of your property such as an additional bedroom or bathroom.

However, it’s important to keep a close eye since this is where your main roof often sheds rainwater. If this continues, it can increase the moisture levels and overtime, can compromise the integrity of the, eventually leading to a leak via the roofing material or its underlay.

Punctures or Pooling Water

You may have a puncture in your roof that is allowing water to seep through. If this is the case, you will see water pooling on your ceiling or inside of your attic.

You might also have a puncture in one of your skylights, which will cause water to leak through the roof when it rains.

Finally, a leaking chimney flashing could be causing leaks in your home’s ceiling.

Need To Fix Your Roof Leak?

The best way to avoid roof leaks is to have your roof inspected by a professional every year. They’ll be able to spot potential problems and fix them before they become more serious issues. 

It’s also important that you keep an eye out for signs of water damage around your home, such as discoloured ceilings or stained walls. If these signs don’t go away, it might be time to call in someone who knows what they’re doing!

If you’re still wondering why does a roof leak, simply get in touch with our team for a free consultation. Our team at SPS Roofing Ltd will be more than happy to address your issues and fix them if required and provide all aspects of roof leak repair.

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SPS Roofing Ltd is a highly rated roofing company based in Exeter operating across Devon and South West England including Somerset, Cornwall, Wiltshire, Gloucestershire and Dorset.