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Roof Leaking Water? – Detection and Repair (7 Common Causes)

Roof Leak

Having a roof leak at your home or business can be a frustrating thing to deal with for a number of reasons. Plus, roof leaks can vary a lot depending on the design and construction of the property involved. For example, a flat roof leaking is different to a tiled roof leak or a roof light leak.

The other thing is that, although they can happen suddenly, roof leaks often happen slowly over time and you may not realise that you have a leak for some considerable period. Clearly, this can mean that water damage can be occurring for a long duration before you spot it.

Roof Leaking
Roof Leaking Water

In this useful guide, we will run through some of the top roof leak causes, explaining how they vary from each other. Before that, it is worth quickly pointing out that often, but not always, roof leak water is commonly from rainfall water ingression into your roof space and below, not tap or central heating water. But more on that later!

We can help with roof leak detection, it is just one of the types of water leak we help locate. We offer the service to both domestic customers homes and businesses locally, with our professional commercial leak detection services.

Roof Leak – Spotting the Signs

Prior to running through some of the most common roof leak causes step-by-step, it is worth listing a few things that might give you a clue that you have a leaking roof at your home or business.

Some of these are included in our article explaining the signs of a water leak, which covers more than just roof leaks. Here are the things to watch out for

  1. A damp patch on your ceiling or walls at high level
  2. Especially damp patches after rainfall events
  3. Bubbling or flaking of paint in the area
  4. Related to these, issues with mould in that area
  5. Cracks or sagging in your ceiling plaster or joists
  6. Damp or moisture in your loft space if you have one
  7. In bad cases, water visibly dripping through the ceiling

Regarding some of these on the list, we have some other useful related guides:

Roof Leak - Wear and Tear
Roof Leak – Wear and Tear

1) Roof Leaks from Wear and Tear / Age

Roofs are one of the places on a property which are directly exposed most to the elements, not only from the rain, snow and hail etc, but also from, UV rays, the heat and cold at various times of the year. This in turn can put pressure on various types of roof, possibly causing cracks or gaps that leak water, especially during or after rainfall.

These roof leak cracks can often start small and get worse over time as they expand, often at joints in the roof or where the roof meets other parts of the building structure or other materials, such as bricks on chimneys, this can lead to chimney leaks in a property which may manifest itself as a leak in or near your fireplace (far from the source).

This will vary by material but, different roofing can have varying lengths of lifespan. As a guide, and it will vary by material and quality too, the expected lifespan of various roofing materials:

  • Felt Roof – 5 to 10 years (more with better quality felt)
  • Roof Shingles – 10 to 20 years
  • Metal Roof – 30 to 40 years
  • EPDM Flat Roof (Ethylene Propylene Diene Monomer) – 50 years
  • Cement Tile Roof – 40 to 60 years
  • Clay Tile Roof Tiles – 50 to 60 years
  • Slate Tile Roofs – 70 to 80 years +

Again, these are a guide, and a number of factors can be at play, not least the location, climate, direction of the roof (vs the sun and other elements) and other materials in proximity, especially timbers materials within the roof too.

Storm Damage Roof Leak
Storm Damage Roof Leak

2) Storm and Weather Damage Roof Leaks

Clearly, this has similarities with the previous example of a roof leak, but often leaks from bad weather (wind and rain) or storm damage can be more sudden or catastrophic, possibly with other damage. We discussed this in our article about Storm Arwen Damage.

That said, storm damage might not immediately cause a roof leak. It could be more gradual and simply contribute to existing wear and tear, it will vary (as will the severity of the storm). Plus, an old roof with existing damage may be less robust than a newer roof. Similarly, different types of roof may be more susceptible to different types of damage.

For example, tiles and slates may be affected more by wind (coming loose etc) vs a flat roof. The final thing to consider as part of this is that there can be indirect, secondary damage whereby not only is the roof leaking but the broken items may break pipes etc in the immediate vicinity, like pipes in a loft or attic space leaking. On this, see our article regarding loft tank leaks.

Speaking of secondary damage, do remember that most roofs (especially modern ones) will have secondary back-up methods to protect from roof leaks, especially with underfelt or other waterproof membranes underneath tiles for example, in modern times these are mostly commonly ‘breathable’ materials which stop water but allow for air to penetrate.

New Roof Leak
New Roof Leak on House

3) New Roof Leaking – Installation or Snagging

Whether it is a brand new house roof leaking or a newly fitted roof leaking, one of the times you can experience a roof leak is soon after installation. This can be for a variety or reasons including poor workmanship, damage during construction, something being missed or even faulty materials, possibly with defects from being manufactured or being broken during transportation.

Whatever the reason, it is always a good idea to keep an eye on a new property for water leaks, and not just roof leaks. This may even form part of the snagging list that you or a 3rd party carry out when checking a newly constructed house for defects.

This is not to say that new roofs are especially susceptible to water leaks, however, they do occur just like other things on this list. A well constructed roof, installed correctly, with good materials and workmanship can be expected to last many decades, or even centuries if you are lucky!

Roof Damage Water Leak
Roof Damage – Water Leak

4) Roof Leak from Accidental Damage

The next on our list covers a wide variety of possible reasons contributing to a roof leak, coming under the umbrella of general damage or accidental damage causes. The list is effectively endless but things such as having building work (or other repairs), solar panel installation, roof light windows installed, gutter installation or repairs could contribute to this.

You can also get damage to a roof from pests or wildlife animals in general, especially those that are invasive. For example, pigeons nesting under solar panels or mice, squirrels or rats trying to get into your loft space to nest, especially in winter, could cause damage resulting in a roof leak.

It is possible that such damage can be caused from the inside on on occasion too. Like having work done in your loft / attic space, or reinsulating it etc. So if you have had work done on your property, especially in the roof area and you notice a roof leak soon after, that could be a related cause of it.

Please remember that, if you have Trace and Access on your home insurance policy, the cost of finding and fixing the water leak could be paid for by your insurer. It’s worth checking what your specific cover is for your home or business.

Roof Leak Flashing Joint
Roof Leak – Flashing (Lead) & Chimney

5) Leak from Roof Flashing, Ridges, Junctions and Connections

This section of possible causes of a roof leak can be very much related to other items on this list. That said, it also covers a number of things such as lead flashing leaking, chimney leaks, ridge tiles leaking etc. These transitional areas are often where one part of the roofing structure connects to another, often including different materials – for example, tiles to bricks.

Without the protection of, for example lead flashing, these connections would be much more vulnerable to roof leaks from gaps or cracks, and therefore damage to these (for whatever reason) can also be a leading cause of roof leaks.

On top of this, some of these are close to or actually are a gulley on a roof where water is channelled, like the right-hand picture above. This means they may have more water running over them in greater concentrated volumes and therefore possibly leaking more water. If these spaces become blocked that can be a reason too!

Roof Leak Causes Other
Roof Leak Causes – Other

6) Other Causes of Roof Leaks

In this penultimate section, we are collating a number of other miscellaneous additional possible causes of a roofing leak at your home, of which there are more than this too:

  • Pooling and puddling water (especially flat roof leak problems)
  • Damage to facias and soffits on a roof (wooden or plastic / UPVC)
  • Blocked or damaged guttering overflowing near the roof
  • Blockages from ice and snow on the roof (‘Ice Damming’)
  • Damage to chimney stacks, chimney pots or cowls
  • Roofing leaks from roof ventilation / vents / soil stacks
  • Damage to sealant or loss of sealant / mastic / silicone
  • Cracked plastic (e.g. on conservatory roof leaks)
  • Rusting to bolts or fastenings (especially metal roofs)
  • Corrosion and rust (also metal roofing leaks)

We could list many more common causes of roof leaks in your home or business but these are some of the more common ones. Again, they can vary in severity and extent.

We hope you’ve found our list of the top causes of flat roof leaks handy, if you have a roof leak in your home but, feel free to contact us for help from our team of water leak detection experts who are experts in a variety of advanced leak detection methods.

7) Not Actually a Roof Leak – Something Else!

Finally, we’ve reserved this section for things that can in some instances be confused for a roof leak. In some instances people think they have a roofing leak but it is something else. We have written more about these things in other guides and so have linked to them.

On that last one about humidity, you may find our review of PIV Units effectiveness useful. logo logo

Leaking Roof FAQs:

What to do when you have a leaky roof?

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When you have a leaky roof, the first and most important step to take is to locate the cause of the leak. Otherwise, any work you do to repair the damage could be compromised next time it rains for example. Secondly, you need to repair the roof leak to stop it leaking. Finally, you need to evaluate and sort the water damage caused by the roof leak.

How can I tell where my roof is leaking?

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In order to tell where your roof is leaking, water leak detection experts can be very beneficial. They can help to locate the cause of the leak, evaluate any damage it has caused in the vicinity. This may involve doing tests such as salts tests to see if the water ingress is from rain water or something else other than a roof leak, like a ceiling pipe leak.

Are flat roof leaks common?

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Flat roof leaks are one of the more common types of roof leak, especially considering that there are more conventional roofs than flat roofs in the UK, relatively speaking such leaks are a decent proportion. Flat roofs have can be susceptible to leaks, especially if there are issues with pooling water or cracks in the material. Many flat roofs have been patched previously, which can over time, weaken and leak again.