Leaking newer 3/12 roof w/min venting
My friends have a roof that is no more than 5 years old and its leaking in several places. Its an asphalt comp shingle, and there are quite a few things, i.e. ceramic chimney with 4 flues, numerous plumbing vents, a swamp cooler, cooktop flue coming through but all look nicely sealed/flashed.
Since it’s approx a 3/12 pitch and in the middle of winter they get a lot of snow (2 to 3 feet), by Utah standards, and they are on the shaded side of the hill/mountain with trees, is the pitch just too flat for what they really need?
My friend said they should tear the whole roof off and cover it with ice/water shield. That seems like an expensive fix.
Oh, in addition, there is only one small gable end vent for the whole roof and I don’t know if insulation is packed-in/covering all the eaves for little or no attic ventilation. I know bad ventiation has to be making the ice damming worse but how much does it really help cure ice damming (good ventilation, that is).
Thx Clark
Replies
Just a few questions.............
Has anyone crawled the attic to determine exactly where the leaks are?
Are they all at the Ice Dam elevation or elswhere?
What is the overhang length at the eaves?
Exactly what is the ventilation set-up?
Does the bath/kitchen exhaust fan vent directly into the attic rather than thru the roof?
Where does the clothes dryer vent?
Is there a ventless fireplace in the house?
Is the range gas or electric?.....and is it heavily used?
Is a humidifier used in the winter?...and at what %humidity is it set to turn off?
Are there leaks when it rains in the other seasons?
Do the windows sweat in the winter?
.......................Iron Helix
I have some answers for you. The leaks are in various parts of the house/roof. The roof is a gable roof with the center of the house being vaulted. The two opposite ends have standard ceilings. Some of the leaks have happened at the ice damming area/eaves. There is only one vent for the whole roof, they need way more venting. As far as I know, all the dryers, stove, bath fans vent outside and not into the attic. The fireplace is open and/or retrofitted with gas logs.
I am going over there soon to see about how far the insulation goes to the eaves and if there is any other ventilation or other problems like a leaking swamp cooler line to/through the roof.
Thanks for all the incitefull questions
Clark
Sounds as if there maybe more than one issue here. Ice daming areas should be obvious as the damage to the plywood will show at the freeze thaw line and down to the gutterline.
If the damage is at the very edge of the eaves then it maybe an installation problem with the drip edge/felt/gutter/fascia/ or other complications....need to have visual information.
The other areas that you have leaks may be from faulty flashing or roofing application. Once again.....need to see the details.
I would really reccomend that you get a professional to look at this situation.
As to the gas logs....if the flue is open then okay, but if it is closed to keep the heat in, then all the water vapor produced while burning is released into the house which will migrate through the ceilings and then condense on the roof sheathing. The gas logs can produce carbon monoxide....be sure to have an upscale metering detector!
Likewise overuse of a humidifer resulting in greter than 30% humidities will cause problems as descibed above. Lots of indoor plants with a heavy watering schedule....ditto. Fish lovers with lots of tanks and lots of water....ditto. An indoor fountains/water garden....ditto.
Low pitch roofs are notorious for short lives and easy leaks!
It would also be helpful to know what your climate is, in order to adress the potential water issues.
..............Iron Helix
If this was a roof of a customer of mine I would do the following
1- add more soffit vents, may be even a few roof vent.(Solar powered?)
2- add heater wires along lower edge of roof or where Ice daming could occurer
3-If the problem still occured I would add a 32" metal flashing to match the house roofing material along lower section of roof to incourage snow and ice melt to slide off the roof, some times if the evestrough is to high it can also hold ice and snow and cause ice daming.
4- If left to contiune you will soon find mold growing on exterior walls in the upper corners and behind the drywall then you re4ally have a problem.
George
A quick answer: yes, ventilation will help prevent ice dams. You want a cold roof in winter and ventilation keeps the roof cold. That way the snow doesn't melt and run down to the cold edge at the overhand where it freezes and makes the dams. I guess it was Iron Helix who relied second and he has very good points you should check out. I jumped in to my reply before I read them all, but does the chimney have a cricket (saddle) so snow, ice and water don't back up upslope from it?
I'd try the things Helx suggested before I'd think about tearing the roof off. 3/12 is pretty low, but still. Oh, the snow isn't so deep it covers the vents and then melts and runs inside them, right? I'll shut up now and read what the other guy replied so I don't repete things he suggested. Hey, it's morning and my fist cuppa hasn't taken hold. :-)
Yep, ice damming is very likely the problem here. When this occurs ventillation is the first suspect.
Another problem, though, is that with lots of large penetrations you can get dams in the shadow areas around the penetrations. A complex roof (valleys or multiple levels) can also result in shadow damming.
And of course the penetrations may be conduits for heat from the house.
First step is to ventillate better, then seal all penetrations into the attic. But if shadow damming is the problem then tearing off those areas and installing ice shield may be the only answer.