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Kadath 09-01-2011 08:13 PM

Need help to locate leak in roof (pictures)

We moved into our house a year ago. We just had our first leak with the Irene storm (probably because of the strong winds, but it wasn't hurricane strength here in Canada though). The previous owners told us that they did have a leak two years ago but had it fixed without further issues. Well it looks like whatever the fix was, it wasn't that great.

It's a cathedral ceiling so there's no attic to locate the leak. I'm posting a few pictures here hoping that an expert can tell me the most likely spot for a leak.



nealtw 09-02-2011 02:13 PM

I am not a roofer but there are a couple thing here I would question. Flashing on the sides of the dormer. The least I would want is a little flashing tucked under the shingles near the top of the dormer to deflect the water away from that side. It looks like the overlap was cheated, I don't think you should see any black.

oldognewtrick 09-02-2011 06:23 PM

Wow... you have a mess, sorry. Almost everything is, well, just wrong. You should NEVER have roof cement exposed to UV rays. So this tells me there was a suspected flashing (or lack of flashing ) issue. Next, the roll roofing is lapped back wards and is also loosing granules. Both could be a leak. Next, the window comes in contact with the roof deck, this doesn't allow for and transition flashing under the window. Next, no overhang on the roll roofing. This could allow water to wick up under the roof. Next, I think I'm seeing exposed nail heads around the perimeter of the flat. These will eventually leak and rot the substructure. Next, the water valleys of the shingle tabs are expanding and the shingles are starting to curl. Early signs of shingle failure.

Besides that it looks like your grass is nice and green.

Oh, and :welcome: to House Repair Talk!

BridgeMan 09-03-2011 01:44 AM


Despite what others may have said, your roll roofing is NOT lapped incorrectly. The lap is correct for the downward flow of runoff on the small shed-type structure.

But you do have a few other issues, the two most serious of which are possible lack of flashing and exposed roofing cement used to cover suspect joints.

A possible quick and easy fix (at least, for buying some time), if you don't want to tear everything apart, is to get a gallon or two of liquid asphalt (Henry's 201, or equivalent). Carefully swab it over all surfaces, then broadcast a heavy coating of roofing granules over it while still soft and preferably before it has a chance to build up a head of steam flowing downhill. You may have to go to a roofing supply place for the granules, as I've never seen them at the big box stores. I've been told they come in colors, but around here I've only seen and used white. Saturating the liquid asphalt with them will stabilize the asphalt, making it more resistant to UV damage and cracking. Two thin coats will be better than one thick, as your pitch could complicate things. A quick wire-brushing of everything before you start is advisable, to get rid of all of the loose stuff. Also, you might have to build a few temporary dams to keep the asphalt from running away, onto the shingles--maybe using duct tape and rubber backer rod, or whatever, to build up some "stoppers".

Then save your shekels (or is it still loonies up there?), and plan on a complete new roof, with proper flashing at all juncture lines, in the next year or two.

oldognewtrick 09-03-2011 07:48 AM


Originally Posted by BridgeMan (Post 60651)

Despite what others may have said, your roll roofing is NOT lapped incorrectly. The lap is correct for the downward flow of runoff on the small shed-type structure.

Then save your shekels (or is it still loonies up there?), and plan on a complete new roof, with proper flashing at all juncture lines, in the next year or two.

Bridgeman, I respectfully disagree. Laps should always allow for the travel of water to pass over not under if a seam should come loose. The way its installed is like tucking your rain coat into your pants and wondering why the water is getting your britches wet. The seams on the outside edge are over the field sheet, not under. This will channel water under the outside edge patch. The field sheets look to me that the seam laps toward the shingle roof not away as it should.

Regardless of our opinions, what the homeowner has is an improperly installed patch and he has a problem. The problem with trying to patch an issue like this is that trying to get caulkings/coatings to adhere to old material. The patch will fail and its like an A/C unit, they don't fail on a cool fall day. It's usually the hottest day of the year. Snow, rain and ice damming will probably make his problem worse.

BridgeMan 09-03-2011 11:39 AM


Take a closer look at the second photo, which (to me) clearly shows water runoff on the brown roll-roofed structure flowing from upper left to lower right, where it meets the shingled roof and reverses its direction of flow. If water naturally flows uphill in your part of the country, then you are correct, and the roll roofing lap is wrong. However, I suspect the force of gravity as most of us know it still prevails in Canada, meaning the roll roofing is lapped correctly.

oldognewtrick 09-03-2011 02:18 PM

I would venture a guess that what we are seeing is a flat roof and the dormer is not canted from left to right. Just my guess. Gravity does not necessarily follow common laws of physic in middle Tennessee thats for sure. Maybe Patrick could let us know if this is indeed a flat roof or if it has reverse pitch toward the house.

We can debate how many angels can dance on the head of a needle all day and at the close of business he still has a roof needing replacement.

BridgeMan 09-04-2011 02:38 AM

The roof of the dormer structure is pitched, as stated earlier. Look at the angle made by the vertical siding with the fascia at the top--if the roof were flat as you contend, it would be a 90-degree angle, but it's obviously not, showing as an acute angle going downward towards the main roofline. With the intent of muddying the water, you can argue forever about "angels on the head of a needle" (sic--around here they do their thing on the head of a pin), but just eyeballing the orientation of the dormer roof with the vertical wall corner of the neighbor's house in the second picture shows the roof to be pitched, sloping downward towards the shingled roof.

And meaning the roll roofing lap is correct.

oldognewtrick 09-04-2011 10:36 AM

I found no mention of the roof being pitched back toward the house in the original post, but for the sake of argument lets say it is, thats the least of his problems.

There is no quick easy fix that will with stand the coming winter for him and not result in further leaking. He needs to figure a way to dispense some loonies/ shekels/$$$ so he doesn't go throwing good loonies after bad.

...and if your angels dance on pin heads I can understand that, I guess ours are a little more specialized ;)

nealtw 09-05-2011 09:46 PM

Oldog; Hold a square up to the second photo and see the slope of the dormer, the rain deverter at the joining point is level. That's my story anyway. This roof is not looking good. I will bet someone put 2" foam under this roof without doing anything about flashing.

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