The Search for Hidden Roof Leaks

The other night, I was getting dressed to go out for the evening when I heard the most ominous sound a homeowner can hear: Drip . . . Drip. To my chagrin, a rivulet of water was making its way down the bathroom wall and dripping off the chair rail.

Within seconds I was in the attic, crawling around the ceiling joists with a flashlight (not an easy thing to do in heels, I might add), trying to trace the water back to the source of the leak. Turns out, there was not one but SIX leaks, scattered here and there around the attic! Eight, if you count the steam coming out of my ears as I dove around with plastic buckets.

I’m a woman trying to sell a house, I have a showing in less than 24 hours, it’s pitch dark and raining frogs and toadstools, and my roof has taken on the characteristics of a kitchen colander. I’m covered in insulation dust, I’m expected at a holiday party in five minutes, I’m almost out of buckets, and a new roof is NOT on my Christmas list!

I couldn’t do anything more about it right then, but as soon as the sun came out the next day, I hauled out my rickety old extension ladder (lovingly dubbed “The Widowmaker”) and headed up to investigate the roof.

Roof leaks are tricky buggers – water can sneak under a broken shingle at one end and snake its way along the underlayment before seeping into your attic someplace else. Once in the attic, it can follow pipes and joists for long distances before finally dripping onto your ceiling.

To add insult to injury, sometimes it only happens when it’s raining hard, or the wind is just right, or you had eggs for breakfast. And don’t get me started on the fact that something supposed to repel water is made from thousands of individual pieces – full of nail holes attaching them to something that rots when it gets wet!

Anyway, I headed up to the roof armed with measurements to locate the drips, but I knew that the problems could be anywhere.

How to Find a Roof Leak

My roofing experience is rather limited, but I did know enough to:

          Seal exposed nails.

Start at the Source

Using landmarks such as edges and vents, I was able to locate the areas of roof directly outside the wet spots. I was looking for loose, broken, raised, or bent shingles, pulled-out nails, and any other damage.

Question the Obvious Suspects

When shingle damage didn’t explain everything, I moved on to inspect the parts of the roof most likely to spring a leak:

  Seal around plumbing vents.

  • Plumbing and furnace vents
  • Chimneys
  • Roof valleys
  • Skylights
  • Ice dams
  • Seams where shingles meet flashing, framing, or masonry
  • Satellite dishes and antennas
  • Ridge vents

Simulate a Rainstorm

Using a water hose, you can systematically test each section of roof to try to find out where the water’s coming from. For the time being, I decided to skip this step. Wet shingles are dangerously slick, and my relationship with the Widowmaker is tentative at best! I’ll come back to this if I need to.

                                          Seal joints on ridge vents.

Armed and Dangerous

Armed with enough roof cement to glue together a warship, my investigation yielded answers that were, as they say, “clear as mud.” I found:

    • Bent and exposed flashing around the plumbing vent, an easy fix. One down, five to go!
    • A small hole in a shingle, probably caused by those wicked walnuts. Two accounted for! Moving on.

    Patched damaged shingle.

  • Here’s where the whole operation took a bad turn. The other leaks weren’t so easy. I crawled all over that roof and found nothing out of place, although I added some sealant under any suspicious shingles just in case.Finally (it’s always the last place you look) I discovered that the sealant on the ridge vent had completely disintegrated, leaving the seams wide open and many of the nails uncovered. Somebody (not me) had used silicone, which eventually broke down over time.

    The ridge vent had become a virtual funnel, which would explain the sudden appearance of so many drips in different places. I sealed that thing like it was the space shuttle!

                                  My freshly repaired plumbing vent.

Watching the Skies

Having attacked the roof like a tar-coated ninja, I slowly backed away and am now waiting for confirmation that it worked. We’re forecast to have rain tonight, so I’ll be spending the evening in the attic with a flashlight, daring the roof to spring another leak.

It better not, that’s all I have to say! You’ve heard that saying about a “woman scorned”? Well, that’s nothing compared to the fury of a woman in a freezing attic on a dark night, jockeying buckets like bowling balls.

Further Information


  1. i live in a townhouse. water leaks through the celing over the garage roof area. had roofer look at garage shingels and all seem fine. i hosed the areas over the windows and the a roof frame . once out of the six times i hosed it did the water start leaking through, I could not get it to repeat again! I cant figure out where this leak could be? roofer said probably windows but i hosed around the windows and no water leaks. how long should i wait for a leak to occur after each section of the roof, windows, fascia board that frames the house? im going crazy!!! help! window guy came and he ran water down the window tracks and nothing. yet he tells me hes 95% sure its somewhere around the window or its seal somewhere. says i need to replace window but wont tell me its 100% sure its the window because it didnt leak after he poured water in the window groove tracks. what can I do? no one knows anything.

  2. trying to fine a leak on a older trailer. the roof has been repainted with the correct product, but a small leak has developed and can not fine it. Hope you have a suggestion. thanks

  3. Interesting article. It seems the plumbing vents aren’t flashed with flashing on the roof? I only see covered with shingles and the cement caulking you did.

    • David,
      It’s hard to tell if the plumbing vents had flashing or not, since they’ve been covered in roof cement over the years, but they probably are standard flashed vents that fit under the shingles.

  4. How did it work out? any more leaking? I can hear water dripping on the inside of my bedroom wall after heavy rain and have some drips in the bathroom

  5. Have had leakage on flat roof of kitchen for long with varying intensity. Had partial repairs with no result. Recently redid the whole flat roof and made it water tight, still have leakage. It leaks on several point as soon as it rains. Leakage is from where ceiling meets wall. This is a two storeyed terraced house with the rest of the house with slated roof. The leakage is making us crazy. Any advice? Would expensive tracking firms help? Please advises if possible by email as well.

  6. I have reinsulated my garage here in Oregon and after it was almost finished it rained and found next to opening of garage door 1/4 of the ceiling is wet. dried it up and it continues to come thru the sheet rock(drywall). I’ve looked in attic , the peak of the house, flashing nothing is wet, but yet I have moisture on the garage ceiling. I’ve tried tracing where the water is coming from but no luck. Can anyone help me? One year ago had new roofing with corning sheets, new boots and new vents put in. So I have a delima.

  7. Have water coming along the full length of the bedroom wall at front of house at ceiling level roofer confirmed no water leaking in loft area which is completely dry ! Water coming on after heavy rain resulting heavy condensation on all windows , any suggestions of problem welcome please ?

  8. I have a flat roof with rocks on it. I had several roof repairmen out to find the leak in my living room to no avail. However, it still leaks during a heavy rain. My home is semi attached, and when the neighbors repaired their roof it ceased. A year later the roof is leaking again during heavy rains. HELP

  9. I have a leak that seems to be coming from the chimney. I have covered the top of the chimney with a tarp but still leaking so it might be coming from the base. Also when it rains hard I can here a dripping sound in my fireplace like a water drop hitting hollow metal. Do you think it might be my chimney or is there a problem a little higher up the roof? The shingles seem fine from what I can tell.

  10. I read your article and from having read it I am thinking I might go up on the roof and spread some black roofing patch that has the consistency of thick lard. It is like black cake frosting. I know there must be a leak because on days it really rains very very hard in Dallas, there is water dripping down over the top of our water heater. I also know that the vent pipe over our plumbing is open and catches some water but since I noticed moisture along the baseboard of the closet where the right side wall is an exterior wall, I figure a closer inspection is in order, on the roof, armed with only a half a bucket of black cake icing and a 2 inch rusty old putty knife and hope I don’t fall off cause the roof has some acorns from our Pin Oak tree.

  11. I have a flat roof in a row home in the city. I had a new roof and several coatings, three roofers and I still get a leak but never when It’s raining only hours later. I am at my wits end. I was thinking maybe brick pointing can help? Please help. I’m afraid my bathroom celling is going to be damaged. Also there is no plumbing pipes on the roof only the chimney.

  12. Same problem. New roof and ceiling is wet in 4 spots s approximately 4 feet apart. Roofer can’t find leak saying attic is dry. Never had a leak before new roof installed. Only gets wet with blowing wind and rain.


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