Leaking Roof Guide: How To Find Your Roof Leak & Fix It Fast
This is not an exhaustive list of signs that you may have a roof leak, but if you see one of these, it could point to a roof leak.
How to Find a Roof Leak
Finding the source of a leaking roof can be tricky.
It’s not uncommon for roof leaks to start high and for water to travel down rafters or drywall…
…before dripping through the ceiling or running down a wall.
Sometimes the water will travel several feet from the entry point to the point at which the leak shows up.
PRACTICE SAFETY FIRST – Never climb on a roof while it is raining. If you don’t feel secure on your own roof, please don’t hesitate to contact a professional roofing company. Many offer a free inspection or fast response roof repair services.
If Your Roof Is Leaking Right Now
Go into the attic with a flashlight and some chalk to mark with while it’s raining.
Look for damp spots on the underside of your roof.
Also, look for a thin stream of water flowing down one of the rafters.
Follow the water uphill till the wood is no longer wet.
Look for potential entry points (like roof vents, valleys, loose nails) and mark the area with chalk, so you can examine the exterior of your roof after it quits raining.
While in the attic, if water is not visible on any wood, look for water running down pipes that penetrate the roof, and also look for water around the chimney.
Mark any problem areas with chalk.
After the rain has stopped (and it’s sunny outside) examine the exterior of your roof to look for problem areas that may be causing the leak. We’ll cover some of the most common causes for roof leaks below.
Find a Roof Leak When It’s Not Raining
Start in the attic.
Look for discoloration on wood sheathing or rafters caused by water.
Water stains will often appear darker due to wood rot, mildew or mold.
Some water stains appear light colored.
You may see stain streaks along rafters or other supports.
Look around penetrating pipe vents and chimneys.
Mark the stains and go outside to examine the roof from the exterior to see if you can identify the cause of the roof leak.
Pay special attention to vent pipe and chimney flashing, as these are often the culprits.
Keep in mind, some of these stains may have been caused prior to a recent roof replacement or roof repair.
If a visual inspection both inside and outside the house does not determine the cause of the leak…
You may need to perform a water test.
How to Water Test Your Roof For Leaks
Find a friend to help with the roof leak test.
Here’s how it works.
One person will be outside the house with a garden hose running water over the roof.
The other person will be inside the attic watching the area for water leaks.
Again, practice safety first.
Make sure the outside person is comfortable on a ladder and comfortable on a roof.
The inside person should have a flashlight and a small bucket to catch water when it begins to drip.
The outside person should should begin by wetting the roof over a small area for a few minutes, while the inside person watches for leaks.
Start by soaking the roof low (near the eaves), and work your way up the roof. That way you can better locate the primary area of the roof leak.
The hose should not be spraying high pressure but enough to generously wet each area, as in a heavy rain storm.
The outside person should work in sections and stay in communication with the person in the attic.
As soon as you see water or moisture from inside the attic, mark the area and ask the outside person to look for exterior problems.
Keep in mind that when you identify a problem area causing a leak, there may be more leaks above that.
You may need to fix or patch the first roof leak and continue with the water test to see if there are any leaks further up, especially around chimneys or other roof penetrations.
Common Causes of a Leaking Roof
There are dozens of possible areas where your roof could be leaking, but most of them fall within some very common causes of roof leaks.
Jump to a Specific Type of Roof Leak
Roof Vent Pipe • Roof Air Vent • Chimney • Damaged Shingles • Clogged Gutter • Roof Valley • Roof Nail • Skylight • Dormer • Ice Dam
Leaking Roof Vent Pipe
Roof vent pipes are common areas for roof leaks.
Roof vent pipes (from plumbing or exhaust vents) penetrate the roof and are usually sealed using a collar-style flashing made out of a flexible material like EPDM rubber or flexible PVC.
Commonly called a pipe boot or vent pipe flashing, the flexible seal “hugs” the vent pipe and seals it from water.
However, over time, the materials often degrade from heat and sun exposure and can shrink or split.
This leaves a crack in the seal and an opening for water to enter your roof.
In extreme cases, degraded vent pipe boots can leave gaping holes in your roof.
Vent pipe leaks are very common, and vent pipe flashing should be regularly inspected to prevent roof leaks.
HOW TO FIX A LEAKING ROOF VENT PIPE
- Flexible roof sealant – apply flexible roof sealant (Black Jack Roof Patch, Rubberized Roof Cement) from a can or tube to fill holes, gaps, flashing and loose shingles around vent pipe
- Vent pipe boot overlay – slide a new vent pipe boot over the old vent pipe boot, caulk & seal (watch video below)
- New boot & shingles – replace worn out vent pipe flashing & boot with a new one and shingle around it to provide a better roof leak repair
Roof Air Vent Leaks
Roof air vents allow air to circulate from the underside of your roof to the air outside your roof.
This is vitally important to the health of your roof.
Proper roof ventilation prevents excess moisture buildup under your roof and helps prevent mold, wood rot and rapid deterioration of your roof.
Roof vents come in a variety of shapes and styles.
Your roof might have a ridge vent running along the peak of your roof. Or you might have a turbine vent, free air vent or powered roof vent.
Most vent styles are made to prevent water leaks.
However, some roof vents include a fairly low profile with little overhang on the sides or top.
Allowing a hard driving rain to whip water up into the vent (which then leaks into your attic below).
If your roof vent only leaks during heavy rain, you may be able to create a shield to prevent the rain from entering the vent. Watch this video to see how that’s done.
If your roof vent leaks with gentle rains as well, you may have a problem with the shingles around the vent or exposed or loose nail heads. Or it could be that the roof vent itself is cracked or damaged.
HOW TO FIX A LEAKING ROOF VENT
- Screen guard – shape metal screen wire to form a barrier around the outside of your vent hood to stop hard driving rain
- Flexible roof sealant – apply flexible roof sealant (Black Jack Roof Patch, Rubberized Roof Cement) from a can or tube to fill holes, gaps, flashing and loose shingles around roof vent
- New vent & shingles – replace worn out roof vent with a new one and shingle around it to provide a better roof leak repair
Roof Leaking Around Chimney
The source for leaks around your chimney can be difficult to pinpoint.
If you notice moisture around your chimney during or after a rain, you may have one or multiple issues.
Starting at the top.
Perhaps your chimney cap is damaged, or maybe the chimney crown is cracked (allowing water to leach inside the chimney).
Or it could be that the brick or stone veneer on the chimney has cracks, or you have mortar cracks in your chimney.
These could all lead to water leaks inside and around your chimney.
If you notice the walls are damp around your chimney during or after a storm, it could be that the flashing around your chimney is loose or worn out. In either case, it is likely that the flexible sealant around the flashing has cracked and formed gaps.
Another potential cause for roof leaks around your chimney is the design of the roof above your chimney. If your steep roof creates a sharp valley where it meets the chimney, you may have a buildup of leaves, sticks or other debris that sit above your chimney.
This debris can allow water to pool or ice to build up, which makes degrades flashing and sealants and allows water to leak around your chimney.
HOW TO FIX A ROOF LEAK AROUND THE CHIMNEY
- Chimney cap – a new chimney cap may keep water from entering the top of the chimney (and help keep critters out)
- Flexible roof sealant – apply flexible roof sealant (Black Jack Roof Patch, Rubberized Roof Cement) from a can or tube to fill holes, gaps, flashing and loose shingles around the chimney
- New flashing & shingles – replace flashing and shingles around the chimney, creating a good new water barrier
- Cricket installation – a chimney cricket prevents debris buildup and redirects water away from the valley normally located where steep roof slopes meet the chimney
Damaged or Missing Shingle Roof Leaks
If you’ve noticed a shingle laying in your yard, examine your roof for missing shingles.
Shingles could be missing due to wind damage after being blown off during a storm.
When this happens, your roof may have exposed nail heads or exposed gaps between the shingles laying below the missing one.
This creates a couple different entry points for a roof leak.
And it’s important to replace any missing shingles as soon as possible.
If you don’t see any missing shingles, but you still suspect the leaking roof is related to a shingle issue, it could be that you have a different type of shingle damage.
You might have roof hail damage.
Hail damage can crack or tear shingles at the point where a hailstone hits the shingle. On asphalt shingles, look for small dark spots where granules are missing.
On wood shingles, look for dimples or cracks.
There are other clues that may point to roof hail damage. Look for dents or small dimples in gutters, metal roof vents or metal flashing. Also look for tears in your screens, damaged siding or window casings.
Severely degraded, curling or buckling shingles can lead to a leaking roof, as the shingle edges loose contact with the roof surface…
Creating gaps between shingles, exposed nail heads and rapid shingle deterioration.
Even small gaps or craks on newer shingles can cause a roof leak.
Tree limbs, tree branches, piled leaves or other debris laying on your roof can also cause pooling of water, leading to roof leaks and shingle deterioration.
HOW TO FIX A DAMAGED OR MISSING SHINGLE ROOF LEAKS
- Remove debris – remove all debris from your roof and check to see if you have damage to your shingles
- Flexible roof sealant – apply flexible roof sealant (Black Jack Roof Patch, Rubberized Roof Cement) from a can or tube to fill holes, gaps, exposed nail heads and loose shingles
- New shingles – replace any missing shingles or damaged shingles if they are in a small area
- Roof replacement – if you have hail damage or a severely degraded roof, talk to a professional roofer about a roof replacement
Clogged Gutter Roof Leaks
Your home’s gutters and downspouts are designed to carry water that drips off the eaves of your roof down to the ground and away from the house and foundation.
A properly functioning gutter system protects your roof, siding, foundation and landscaping.
When your gutters are clogged, water and debris will pool inside the gutters while it’s raining.
In severe situations, this water can leach under your eaves and shingles, leaking down into the walls of your home.
Heavy clogged gutters can also deform or separate from your house in areas, which can cause waterfalls that run down down exterior siding or pool in areas of your landscaping or yard.
HOW TO FIX CLOGGED GUTTER ROOF LEAKS
- Remove debris – remove all debris from gutters & downspouts (NOTE: if you see lots of shingle granules in your gutters, you may have shingle damage)
- Gutter shield- install some type of gutter shield to prevent leaves, twigs and other debris from building up in your gutters
Roof Valley Leaks
Roof valleys are created wherever two roof surfaces intersect to form a shallow “V” shape.
Roof valleys carry a lot of water.
Although professional roofers take great care to properly install roof valleys, they can be susceptible to roof leaks.
Due to their shape, they also are a prime spot for debris to collect, which could lead to water pooling in roof valleys.
During the wintertime, roof valleys may collect more snow or ice than the flat slopes of your roof and could cause problems when the snow melts.
Roof valleys may include an additional barrier of protection under your shingles in the way of an ice and water shield. This thick underlayment material offers added water protection around roofing nails and helps protect against ice dams and heavy water flow.
However, not every home uses an ice and water shield in the valleys, and with poorly placed nails near seams and low spots, you might have a leak in the roof valley.
Other roof designs call for metal roof valley flashing to form a solid metal water barrier.
HOW TO FIX ROOF VALLEY LEAKS
- Remove debris – remove all debris from roof valleys, so nothing is touching your roof
- Re-shingle roof valleys – install ice and water shield under shingles or install metal roof flashing and re-shingle the valley
Roof Nail Leaks
Roof nail leaks can happen when roof nails have been loosened slightly from high winds or have simply pulled out over time.
If shingles get lifted or torn from high winds, the damaged shingle exposes nails holding the shingle below it. These nails will eventually rust.
And just one rusted out nail can cause your roof to leak every time it rains.
Nail pops can also occur where the a nail or multiple nails push up and out causing the shingle above to lift, eventually penetrating the top shingle and causing a leak.
Nails or screws that were used for mounting satellite dishes or other roof-mounted equipment can leak. Make sure you patch any holes for equipment that has been removed.
No matter how the hole forms in your roof, it needs to be fixed to prevent roof leaks.
HOW TO FIX ROOF NAIL LEAKS
- Flexible roof sealant – apply flexible roof sealant (Black Jack Roof Patch, Rubberized Roof Cement) from a can or tube to fill nail holes or cover exposed nail heads
- New shingles – replace any damaged shingles using proper nails if they are in a small area
- Roof replacement – if you have several nail pops or loosened shingles, talk to a professional roofer. You may need a roof replacement
Skylight Roof Leak
Roof leaks around skylights are fairly common.
Installation of a skylight creates a large roof penetration that must be sealed around the entire perimeter to prevent leaks.
Over time, it’s not uncommon for roof leaks to form around skylights.
While skylights are designed to shed water, the top edge of every skylight forms a flat surface that raises from the roof surface.
As rainwater flows down the roof, it hits the frame of the skylight.
And if the frame or flashing is not water-tight, it can lead to a leaky roof.
The upper edge of your skylight is also a place where leaves, snow, ice and other debris can collect. This leads to pooling and faster deterioration of flashing and seals.
Bear in mind that while skylights can and do leak, if you see a leak dripping from your skylight, it could be condensation on the inside of the glass or it could be that water leaked into the roof higher up and is exiting out the area of your skylight.
HOW TO FIX SKYLIGHT ROOF LEAKS
- Flexible roof sealant – apply flexible roof sealant (Black Jack Roof Patch, Rubberized Roof Cement) from a can or tube to fill nail holes, gaps or loose shingles
- Silicone caulk – apply 100% silicone caulking to the skylight window or lense to fix any leaks between the window and the frame
- Flashing & shingles – replace the flashing and shingles around the skylight, creating a good new water barrier
- New skylight – replace old skylights that have eroded or continue to have problems
Dormer Roof Leaks
A roof leak at the edge of a dormer can allow a lot of water to enter your home.
Dormer leaks can be caused from a number of issues.
Rotten or missing trim or siding can allow water to leak behind flashing and into your roof.
Worn out flashing or missing sealant can also cause roof leaks around dormers. When inspecting your roof, look for step flashing that has shifted, as this could leave areas exposed.
Pay special attention to areas around dormers where debris has built up or where ice forms in the wintertime.
Look for cracked caulk around window casings.
And also check the upper and lower corners of the dormer to make sure there are no gaps or areas where water could flow under or behind flashing materials.
Another hidden cause for a dormer leaking water is the lack of vapor barrier installation. If the original builder left this out, you could be in for trouble.
HOW TO FIX DORMER ROOF LEAKS
- Flexible roof sealant – apply flexible roof sealant (Black Jack Roof Patch, Rubberized Roof Cement) from a can or tube to fill nail holes, gaps, loose flashing or loose shingles
- Flashing & shingles – replace the flashing and shingles around the dormer
- Trim & siding – repair or replace rotten trim or siding checking flashing integrity and seal, making sure to wrap exposed sheathing with vapor barrier
Ice Dam Roof Leaks
In northern climates ice dams can cause major problems.
What is an ice dam?
An ice dam forms as a ridge of ice along the lower edge of your roof and prevents melting snow (higher up on the roof) from flowing past the dam. Water then pools above the ice and leaks into your roof.
Large icicles hanging from your gutters are often indicative of ice dam formation.
Ice dams are caused by snow buildup and by non-uniform roof temperatures.
When lower sections of your roof are colder than upper sections of your roof, melting snow can freeze near the eaves and cause an ice dam.
A big factor in ice dam formation is heat loss inside your attic. If your home is not well insulated, your attic may be too warm during the winter months. Warm temperatures inside your attic can too much snow melt.
Melting snow during the day and colder temperatures at night can cause ice dams to grow into major problems.
HOW TO FIX ICE DAM LEAKS
- Snow removal – if you’ve had a heavy snow (and your home is prone to ice dams), you can remove snow from your roof using a “roof rake” or push broom, but be careful not to lift or tear shingles
- Insulation – insulation is a preventative measure to reduce heat loss through the ceiling into your attic. The better insulated your home, the less heat will raise to the underside surface of your roof
- Check ventilation – proper ventilation will help equalize air temperature inside and outside your attic, but insulation is the primary tool used to prevent ice dams
Professional Roof Leak Repair
If you notice water spots on your ceiling, find the roof leak fast and fix it to prevent further damage.
If you need help from a professional roofing company, contact your local roofer.
If you are located in or near Tulsa, Oklahoma, give us a call, and we’ll be happy to repair your roof.
We can be reached at (918) 943-3063.