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Common Reasons for Roof Leaks in Heavy Rain


Heavy rain can test the durability of any roof, and small vulnerabilities can quickly escalate into more serious issues, such as mould growth or structural damage. A leaky roof is more than just an inconvenience, with repairs becoming costly if not addressed promptly!

Understanding the common causes of roof leaks during heavy rainfall is essential for protecting your property from long-term harm. From damaged shingles to clogged gutters, this article will explore the typical culprits behind roof leaks and address how to prevent them before they wreak havoc on your home.

15 Common Causes for Roof Leaks in Heavy Rain

There are many common causes of roof leaks during a period of heavy rainfall; some of which you can take care of yourself. However, others may require experienced roofers to resolve. Let's take a look at 15 of the most frequently seen culprits for a leaky roof…

1. Damaged or Missing Shingles

signs roof damage following hailstorm concept hailstorm

Any shingles in your roof that are damaged or missing altogether could cause a leak in your roof, especially in heavy rain. However, it is unlikely that this is the case unless the missing or damaged shingle is directly above an exposed underlay seam. In this instance, a leak may occur quickly and will need urgent attention. 

2. Damaged or Missing Roof Tiles

Similar to the previous point, if any of your roof tiles are damaged or missing, this could be the culprit for your leaking issues. Roof tiles are more durable than shingles, but if your tiles become damaged or fall off during a storm this may cause leaking issues. The waterproof underlay will keep you protected for a while, but this will eventually rot after constant exposure to the elements. 

3. Clogged Guttering

clogged gutter filled with autumn leaves

Leaves, sticks, or any other debris buildup can clog your gutters, and prevent the water from flowing as intended, causing it to back up and pool under your roof tiles. This can eventually lead to leaks, so if your gutter is blocked, get a professional to address this if you cannot safely reach it yourself. 

4. Built-up Debris in Roof Valleys

Roof valleys, where two roof slopes meet, are prone to collecting leaves, dirt, and other debris over time. Much like with gutters, when these areas are clogged, rainwater can't drain properly, causing water to pool and eventually leak into the house. Climbing onto your roof to clear debris is dangerous and is not something we recommend doing yourself; leave it to the professionals to handle if this issue occurs.

5. Poor Quality or Damaged Flashing

Flashing is useful for covering the weaker parts of your roof, such as where a chimney connects to the roof. However, it is only useful if it is free from damage and is of good quality. Damaged flashing can expose these weak points to heavy rain, causing costly problems. Fortunately, regular inspections and the quick replacement of damaged flashing will keep your roof safe.

6. Old Roofing

damaged house

Over time, roofing materials degrade due to exposure to the elements. Older roofs are more vulnerable to leaks after heavy rain, as worn shingles, tiles, or slates lose their protective qualities and allow water to seep through. Replacing an old roof can give you a strengthened defence against the contrasting weather we see in the UK.

7. Poorly Installed Skylights

Skylights are an attractive feature for many homeowners, but they can quickly become problematic if they’ve been installed incorrectly. Poor sealing or gaps around the skylight edges allow water to seep through during heavy rain, leading to leaks around the frames. Over time, the seal around a skylight can also start to degrade, so this could also be the cause of your leak.

8. Damaged Roof Underlay and Membranes

Underlay and membranes provide an additional barrier against water intrusion beneath the roof’s outer layer. However, if they are damaged or torn, moisture can pass through, especially during prolonged rainfall. This can lead to the buildup of dampness, condensation, and rot after leaks begin, gradually damaging the roof structure. 

9. Improper Drainage on Flat Roofing

Flat roofs are popular in British homes, but they can suffer from inadequate drainage. When water isn't properly directed off the roof, it can pool and lead to leaks, causing significant water damage over time. If your flat roof leaks in heavy rain, ensure that your roof features gutters and downspouts to drain water runoff from the foundation, and keep those gutters clear!

10. Moisture Build-up in Lofts

Poor ventilation in loft spaces can lead to excessive moisture accumulation, which worsens during heavy rain. This moisture buildup weakens roofing materials from the inside out, leading to leaks and gradual structural damage. Implement proper ventilation in your loft as soon as you notice any moisture buildup before the issue escalates. 

11. Incorrectly Installed Slates, Tiles, and Roofing Sheets

When slates, tiles, and roofing sheets are installed on your roof, they should be aligned to a certain pitch for proper water runoff. If this isn’t achieved properly, leaks can occur in exposed gaps and weak spots if water pools and flows underneath the slates, tiles, or roofing sheets. 

12. Inadequately Sealed Roof Valleys

Roof valleys are particularly vulnerable to leaks if not sealed properly. When heavy rain hits, water runs down these valleys, and without adequate sealing, it can easily seep into the roof structure. However, roofing experts will be able to handle this issue promptly by replacing the roof flashing in this notorious weak point of a roof. 

13. Damaged Fascia Boards and Soffits

Fascia boards and soffits help protect the edge of your roof from unwanted moisture and wildlife. However, when they become damaged or degrade over time, water can infiltrate the roof’s edge, leading to leaks and eventual decay of the roof’s structural components. Wooden fascia boards and soffits are prone to rot, so replace these with UPVC for greater longevity.

14. Pipe Boot Failures

Neoprene pipe boots are handy for creating a waterproof seal between the roof deck and any protruding pipework, but if your pipe boot cracks or wears out over time due to UV ray exposure, water may begin to seep around the base of the pipe. This is one of the biggest causes of leaky roofs, so look to get an old pipe boot replaced promptly. 

15. Incorrectly Driven Roofing Nails

Roofing nails that are incorrectly driven, either too deep or too shallow, can compromise the roof's watertight integrity, and nails driven at the wrong angle can create gaps where water can seep through. This is a common issue in roofing nails used for shingles and roof decking, but roofing experts will be able to unstick the shingles and fix the positioning of the nails. 

How Can You Temporarily Fix a Leaking Roof From the Inside?

If you're dealing with a leaking roof and need a temporary fix from the inside until professional repairs can be made, we’ve created some top tips to try. Never try to fix an issue on your roof yourself, as this can be highly dangerous - leave that to the professionals!

  • Find the Leak: Locate the source of the water in the ceiling or loft. 
  • Contain the Water: Use a bucket to catch dripping water and prevent further damage.
  • Relieve Pressure: Poke a small hole in any ceiling bulges to drain accumulated water.
  • Apply Roofing Tape: Use roofing tape or a patch to temporarily seal the leak.
  • Use Expanding Foam: Use expanding foam spray for larger gaps, blocking water temporarily.

What Should You Do Next?

Since the weather in the UK can be unpredictable, it's best to address leaking roofs as soon as you notice a leak. The only way you can ensure that the problem is properly addressed is by contacting an experienced roofing team,  otherwise, the problem may persist and worsen, which can hugely increase the costs to fix. 

flooding roof

How to Prevent Your Roof From Leaking

To prevent your roof from leaking, follow these maintenance tips:

  • Inspect Your Roof Regularly: Conduct routine inspections, especially after storms or heavy rainfall. Look for damaged or missing shingles, cracked tiles, or any visible wear, and contact our team if you find anything that isn’t as it should be. 
  • Schedule Professional Inspections: Have a professional inspect your roof at least once a year, or after major weather events, to catch potential issues before they become major problems. Our qualified drone pilot can conduct an accurate roof survey to identify any issues, and our roofing team can promptly address them. 
  • Clean Gutters and Downspouts: Keep gutters and downspouts clear of leaves, debris, and dirt to ensure proper water drainage. Clogged gutters can cause water to back up and seep under your roof.
  • Trim Overhanging Trees: Keep tree branches trimmed away from your roof to prevent damage from falling debris accumulation in gutters and roof valleys, which can lead to leaks.
  • Keep Ivy in Check: While they might look nice, wall creepers like ivy stay attached to your property by working their way into gaps in brickwork and tiles. This can create gaps for water to come through, so it is important to stop ivy from growing tall enough to reach your roof by trimming it regularly.
  • Check Loft Ventilation: Ensure your loft is well-ventilated to reduce moisture buildup. Poor ventilation can cause condensation to build up, which can lead to water damage and leaks. 

Contact Us for Roofing Repairs and Maintenance Needs

At Empire Roofing, our specialists understand the importance of regular maintenance to protect the longevity of your roof. If you notice a leak, our team will work efficiently to ensure that the issue is resolved, keeping your home secure even in the worst of the British weather! If you have any questions, please don’t hesitate to contact us today.

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