How To Find A Roof Leak Guide
Roof Leaks

If you are wondering how to find a roof leak, this post should help! You are able to stop leaks on your own with no experience. We will show you how you can find the leak and then fix the most common roof leaks. Many leaks will only take a few moments to repair. If you have any water stains that extend across the ceiling or are running down the halls, this is probably because there is a roof leak. Tracking down where the leak is coming from is the hard part, but fixing it is pretty easy. We will be able to show you simple tricks for repairing and finding the most common roof leaks. If you live in the Snowbelt during the winter, you will only have leaks on sunny or warm days, you probably have ice dams. We will discuss those in another article.

A. How To Find Roof Leaks 

B. Solutions For Small Leaks 

  1. Plumbing Vent Boot Leaks 
  2. Roof Vent Leaks
  3. Dormers & Wall Leaks 

C. Complex Roof Issues 

  1. Step Flashing Leaks 
  2. Fixing Small Holes 
  3. Leaks Around Chimneys

D. Required Tools For These Projects

How To Find A Roof Leak


  1. when you have (or shortly after) a heavy rain, grab a flashlight and go to your attic, use caution to ensure you do not fall through the ceiling. If you do not have any rain, take a garden hose and comprehensively soak the roof hence creating a manmade leak.
  2. Above the spot where the ceiling is wet make an examination of the roof rafters and decking in the attic.
  3. Having located wet spots or water stains, follow their track upwards to the decking of the roof and/or rafters to their higher most point.
  4. From the highest point of the leak, measure down from the roof peak and over from a gable end to the leak.
  5. Once the roof is completely dry, venture on to the roof and allowing for an overhang on the end of the roof, transfer your measurements to the roof. (Note: Please exercise all safety precautions and warnings when you position ladders and when you are climbing onto a roof. Do not, under any circumstances, go up a steep roof.)
  6. Conduct a thorough examination for signs of the leak at the measured location.
  7. As water can run down and behind shingles, before it emerges in the attic rafters or decking, keep looking higher up when you are on the roof if you cannot locate the source of the leak at your measured location.


How To Search For Leak Signs

If running water isn’t revealing the location of the leak, don’t get timid. Start removing the shingles in the suspected area. When you have them removed, there will be evidence of leaking and you will be able to find the source. You will see water stained or discolored felt paper or possibly rotted wood below or around it. If you are not sure how to do this you can hire a professional roof inspector. Learn more about how much roof inspections cost.

When you are trying to find the leak, begin looking at the roof that is uphill from the stain. The first thing that you need to look for is penetration to the roof. Items that have penetrated the roof are the most common source of leaks. It is really rare for a leak to develop in an open area that has uninterrupted shingles, even on an older roof. Penetration can include roof vents, plumbing, dormers, chimneys, or anything that goes through the roof. They can be a few feet above the leak or to the left or right of it.

If you are able to access the attic, the best way to track down the leak is to search the attic with a flashlight and find the evidence. There will be black marks, mold, or water stains. If access is the issue, or you have vaulted ceilings, you will have to go on the roof to examine the areas.

If the problem isn’t really obvious, have someone go on the roof with a hose. Start out low by soaking the area above where the leak is in the house. Isolate areas when you are running the hose. For instance, soak the downhill areas of the chimney first, then on each side, then on top. Have your helper stay inside waiting for a drip to appear. Let the hose run for several minutes before you move up the roof. Tell them to yell when the drip is visible. You will then be around where the leak is. This process can take an hour or more, so be patient and don’t move the hose too soon. Then take your helper out to dinner.

Minor Roof Leaks Can Cause Major Damage

If you have a roof leak, you need to fix it right away, even if it isn’t bothering you too much or you are planning on getting a new roof in the next year. Even over a short time, a small leak can cause a big problem like rotted framing, mold, damaged ceilings, destroyed insulation and sheathing. A flashing leak that caused an expensive repair bill was very obvious from the ceiling stains. If you have dealt with it right away, the damage and repairs are pretty minimal.

Solution For Small Leaks

There are some small roof leaks that are really hard to find. Sometimes the water will show up at a place where the leak isn’t. If the ceiling has a plastic vapor barrier between the insulation and drywall, push the insulation away and look for flow stains on the plastic. Often times the water will run to openings in the vapor barrier such as ceiling lights.

If you aren’t able to see any flow marks, and the stain is really small, look at the underside of the roof for shiners. Shiners are nails that have missed the framing. Moisture that escapes into the attic from rooms below will condense on the cold nails. Sometimes you will be able to see this if you climb in the attic on a cold night. These nails will have a white to them because they have become frosted. Whenever the attic begins to heat up, the frost will melt and drip, then it starts over again. The solution is to clip the nail with side cutting pliers.

Fixing Common Leaks:

How To Fix Plumbing Vent Boot Leaks

Whenever gasket type plumbing vent flashing begins to leak, the culprit is normally a missing/loose nail or cracked gasket.

Plumbing vent boots can be made of metal, plastic, or plastic and metal. Check the plastic bases for any cracks and metal bases for a broken seam. Then examine under the rubber boot that surrounds the pip. This can be torn or rotted which allows water to work its way into the house through the pipe. With these issues, you should purchase a new vent boot to replace the old one. If the nails at the base are pulled free or missing, and the boot is in good shape, then replace them with a rubber washer and screws that is used for metal roofing systems. You will find these at home centers. You will have to work the surrounding shingles free. If you do not have any type of extra shingles, then ensure that you are careful when you remove the shingles so that you can reuse them. Use flat bars to separate the layer’s sealant. Then you can drive the flat bar under the nail head to pop up the nails.

How To Fix Roof Vent Leaks

Plastic roof vents may leak and crack. Duct tape isn’t the answer this time.

Be sure that you are checking for cracked housing on the plastic roof vents and the broken seams on a metal housing. You may be really tempted to just throw caulk on the issue, but that won’t last too long. There isn’t a fix other than replacing the damaged vents. You should also look for any missing or pulled nails on the base. Be sure to replace them with a rubber washer screws. You will be able to remove the nails in most cases. There are nails that will be across the top of the vent as well. You can work those loose without having to remove the shingles. Screw the bottom in place with your screws. Then squeeze a bead of caulk beneath the shingle beside the vent to hold the shingle down and to add water barriers. That is a lot easier than having to re-nail the shingle.

How To Fix Dormers & Wall Leaks

Water that managed to sneak between dormers and walls will dribble down into the house similar to a roof leak.

Water doesn’t just come at a shingled surface. Often times, wind-driven rain will come in from above the roof, normally around the windows and between siding and corner boards and will come in through knotholes and cracks in siding. Dormer walls will provide a lot of places where water can dribble down and enter the roof. Caulk may be cracked, old, or missing in areas between the corner boards and between siding and window edges. Water will penetrate the cracks and will work its way behind the flashing and into the house. Even caulk that looks like it is in intact may not be sealing right. Dig around with a putty knife to see if the area happens to be sealed. Dig out old caulk and replace it with a latex caulk. Be sure to check the siding. Replace rotted, missing, or cracked siding, ensuring that the new piece is overlapping the flashing by two inches. If you still have a leak, then pull back the corner boards and check the flashing in the corners. Often times there is hardened, old caulk where the piece’s overlap.

Complex roof issues

Roof leaks that are during storms in summer or snowy parts of winter, and due to poor flashing. The soffit that happens to be meet the roof is a really hard area to waterproof. Ice dams happen when the snow melts and then water freezes when it hits the colder edges of the roof. Eventually, the water will begin to pool behind the dam and it will work its way under the shingles and under the soffit until it finds an opening.

The solution starts with good flashing since this will stop leaks from rainfall and may stop the leaks from ice dams. Start by removing the shingles down to the wood sheathing and slip the strip of adhesive water barrier under the soffit joint. Depending on how the roof is joined, you may have to cut a slot to work it in. It should overlap another piece of water barrier that is laid below and along the roof edge. This should cover most of the leak-prone areas. Then simply re-shingle, sliding the metal step flashing between the trim behind the gutter. The valley flashing, that is laid over the joint where the roof meets should overlap at least 2 inches of the flashing.

If the leaks continue to happen from the ice dams, you should consider installing heating cables. Improve the attic ventilation and insulation are great ways to keep ice dams from happening, but they aren’t as effective in a complex roof issue.

How To Fix Step Flashing Leaks

Step flashing that isn’t nailed can slip and channel into the wall.

Step flashing is normally used along the walls that intersect the roof. Every section of flashing will channel water over the shingle downhill from it. But if the flashing rusts through, or some comes loose, water will go behind it and it goes into the house. Rusted flashing will need to be replaced. That means you have to remove shingles, pry the siding loose, and remove it to replace it. It is that simple. But normally, a roofer will forget to nail it in place and it will slip down to expose the wall.

Fixing Small Holes

The holes that are in shingles can be sneaky due to the fact that they will rot and have other damage for years before you even notice a leak. You may find holes from a satellite dish or antenna or anything. Misplaced, exposed roofing nails need to be pulled and then patch all of the holes. Small holes are really easy to fix, but you don’t just inject caulk into the hole. You fix it with flashing.

How To Fix Leaks Around Chimneys

All sorts of bad things can happen around a chimney. There are too many issues to cover in this area. Flashing around a chimney may rust if it is made from galvanized steel, especially at the 90-degree bend that is at the bottom. A long term, but a quick fix is to slip new flashing under the rusted one. That way water can be diverted. But, the best fix is to cut a kerf into the mortar and install new flashing.

Required Tools For The Project:

You need to have these leak repair tools lined up before you begin and you will save yourself time and a lot of frustration.

  • Tin snips
  • Putty knife
  • Pry bar
  • Flashlight
  • Drill/driver (preferably cordless)
  • Caulk gun
  • Hammer
  • Garden hose
  • Plumbing boots
  • Roof vents
  • Rubber washer screws
  • Roofing nails
  • Siding caulk
  • Roof caulk
  • Metal flashing

Roof Leak Detection & Repair Phoenix & Mesa

Thank you for reading “How To Find A Roof Leak”. Stay tuned for more from the roof leak detection and repair experts at Right Way Roofing Inc. We can help with roof leak detection and repair in Phoenix & Mesa, Arizona. Contact us today for a free quote.



Call us TODAY! East Valley: 480-232-5458 or West Valley: 602-299-8851