roof leaking

[Gilbert]

CONFUSED. New roof installed using 2 Venmar vents. Inspected a 4/12 roof and shingles and they are installed correctly. The shingles bonded together but during heavy rains the water makes it way into the attic, runs down the rafter on the opposite side of where the vent is installed. Vent is about 18 inches from the peak. The only thing I can see is the vents are letting in wind-driven rains. I always thought these vents were very good. Unless there is something I'm missing. Any ideas?

[Raymond Wand]

Water could be entering through the ridge shingles or through base of vent due to improper installation and/or bad flashing at base of vent.

[Jerry Peck]

CONFUSED. New roof installed using 2 Venmar vents. Inspected a 4/12 roof and shingles and they are installed correctly. The shingles bonded together but during heavy rains the water makes it way into the attic, runs down the rafter on the opposite side of where the vent is installed. Vent is about 18 inches from the peak. The only thing I can see is the vents are letting in wind-driven rains. I always thought these vents were very good. Unless there is something I'm missing. Any ideas?

I am confused:
- The shingles having bonded together does not affect the water-tightness of the roof. This brings up the question of 'Is there underlayment under the shingles, and, if so, how is it installed?'.
- The shingles are installed correctly, the vents are installed correctly, or both? How do you know?

[Gilbert]

I am confused:
- The shingles having bonded together does not affect the water-tightness of the roof. This brings up the question of 'Is there underlayment under the shingles, and, if so, how is it installed?'.
- The shingles are installed correctly, the vents are installed correctly, or both? How do you know?


Ice & water shield 3 feet only from eaves. No underlay for the rest of the roof.
- roof covering July 2015
- Looked at the roof from the ground all tabs and seams line-up
- I walked the roof and started with the ridge shingles and pulled on the shingles around a 8 foot perimeter to find any gap, loose shingles, nailing heads etc...
- Caulking present.
- Inspected the vents the same way. The vents are silicon in place, they are solid.
Also (looking from inside the attic) the vents are on the south side and the water drips down the north side. If the base of the vents were not properly installed, water would flow down the same side.
That is why I'm puzzled. The only thing I can see is the size and slope (4/12) of the roof contributing to the water being pushed into the attic. Is it possible for the vents to let in that much rain, almost 2 feet away.
I think this is one problem where you would have to see in person. Love this site and I value every ones opinion Thanks.

[Mark Reinmiller]

If you are saying that the leak is at the opposite side of the roof then where the vent is installed, I think the vent is not the issue.

[Garry Sorrells]

Gilbert,
First off Some picts of the interior and exterior might help come up with a theory of condition/problem.

Then after figuring out that you are in Timmins,Ontario, Canada I can not believe that you would have driving rain that could drive through a vent and travel 2 feet horizontally to the opposite side of the roof. Lite dry snow with enough wind maaaaaybe. But then that is a stretch for it to cling and melt on opposite roof side.

I think that trying to focus on vents as the cause is a distraction. You could test your theory with a hose and see if you could recreate the water on the opposite side rafters. But I would put money on not being able to do it.

Looking at the ridge and then working your way down (interior and exterior) is the only logical process. Flooding the roof with a hose and working up to the ridge to find where it starts to leak is the only way to find what you can not see.

Then again have you tried an IR camera ?
How about a contact moisture meter to back track the leak?

[Raymond Wand]

I don't think a hose is going to be much use since the temps in Timmins are in the low to mid teens this last week and for the week to come, not to mention the snow cover.

Timmins, ON - 7 Day Forecast - Environment Canada (http://weather.gc.ca/city/pages/on-127_metric_e.html?unit=imperial)

[Jerry Peck]

Ice & water shield 3 feet only from eaves. No underlay for the rest of the roof.

I think that is the issue - no underlayment to serve as the secondary water barrier. The roof deck is serving as the secondary water barrier and water is going between the joints.

[Bruce Ramsey]

Ice & water shield 3 feet only from eaves. No underlay for the rest of the roof.

- Caulking present.
- Inspected the vents the same way. The vents are silicon in place, they are solid.

I think this is one problem where you would have to see in person. Love this site and I value every ones opinion Thanks.

Caulking and silicon are not needed if the roof and vents are installed correctly.

[Kevin O'Hornett]

I agree with Jerry re: the lack of any underlayment other than the ice and water shield at the eaves. Just a note: Roof coverings on sloped roofs are typically designed to shed water, not to be watertight. Low slope and "flat" roof coverings are designed and intended to be watertight.

[John Kogel]

It may be a condensation issue inside a very cold attic with warm air leaking in from downstairs.

[Kevin O'Hornett]

Based on my on experience in cold, damp climates (Minnesota), attic moisture issues related to attic bypasses (moist air leakage into attics from interior habitable spaces) typically manifest as evidence of condensation in multiple areas of attics rather than in only one area.

[Raymond Wand]

If this is an Venmar vent refer to installation -

See pages 16, 17, 19.

http://www.venmar.ca/DATA/DOCUMENT/151_5_en~v~Installation_Manual.pdf

I would be paying very close attention to the ridge shingles. Even though they may be secure it does not mean they are not leaking. Wind driven rain can also be a culprit at the ridge.

[Ian Page]

I'd be very suspicious of the upper vent flashing, the small roof directly above and the ridge shingles. The fact that the shingles all line up and appear to be installed correctly is not any assurance of their efficacy. Like Jerry, I'd also be concerned about the lack of underlayment.

Is there a framing 'path' or collar tie in the attic in close proximity to the upper side of the vent allowing water to follow to the opposite side of the roof? I don't think it's a wind driven issue. A hairline crack in the fold of the vent flashing could also be the cause. Hard to say without pics or an on-site inspection.

[Gilbert]

Gilbert,
First off Some picts of the interior and exterior might help come up with a theory of condition/problem.

Then after figuring out that you are in Timmins,Ontario, Canada I can not believe that you would have driving rain that could drive through a vent and travel 2 feet horizontally to the opposite side of the roof. Lite dry snow with enough wind maaaaaybe. But then that is a stretch for it to cling and melt on opposite roof side.

I think that trying to focus on vents as the cause is a distraction. You could test your theory with a hose and see if you could recreate the water on the opposite side rafters. But I would put money on not being able to do it.

Looking at the ridge and then working your way down (interior and exterior) is the only logical process. Flooding the roof with a hose and working up to the ridge to find where it starts to leak is the only way to find what you can not see.

Then again have you tried an IR camera ?
How about a contact moisture meter to back track the leak?




I don't have pics anymore. My comp crashed (long story) I can always get the inspection pics I sent the owner. I think Gary has it right. It will boil down to using water. Keep hosing until I find the culprit. If there is a leak, and there is, use water and we'll find it. And Raymond your right using the hose is no longer an option. We had heavy rain last Tuesday (Dec 22). Never been seen this far north. Winter is here now and I will solve this problem in the spring. If I have to sit in the attic during heavy rain I will bring coffee and lights and I will figure it out.
Thanks Guys... I will definitely let you know what the problem was.