# Brand New Roof - Heavy Frost and Icicles



## olaf (Feb 24, 2014)

Hi,
We had our asphalt shingles replaced last summer and we are now noticing some water markings on our ceiling. I went into the attic space to see if I could figure out what is happening. My relationship with the roofer I had hired for the shingle replacement ended on a bad note and I do not feel comfortable calling them back to repair. What I am not sure about is if what I discovered in the attic is normal. I see heavy frost in the rafters and I see icicles stemming down from a few roof penetrations, like the bathroom exhaust fan. I would expect some frost as we live in a Northern climate and the ambient temperature at the moment is -27DegC (-17DegF). I assume the icicles seen are do to some leakage around the plumbing boots for the exhaust ducting? We had ridge venting installed during the roof replacement and there are no other roof vents. Was told ridge venting would be more than adequate, but now I wonder if some addition venting might reduce the amount of frost. Any advice would be greatly appreciated. Is it normal to see this much frost? Icicles in the attic are not normal, is it normal to have to reseal around the boots on a new roof?


-olaf (newbie)


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## gregzoll (Dec 25, 2006)

You have some huge air leaks from either the bathroom fan, or other points, which is allowing moisture to get up there.

Post the outside at the eves and also the Ridge line, showing any vents on the roof.


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## joecaption (Nov 30, 2011)

It has nothing to do with the shingles.
It's any or all of these, lack of proper venting, air leaks from the living space into the attic, not enough insulation, blocked soffit vents, bathroom, dryer or range hood not going out through the roof.


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## olaf (Feb 24, 2014)

Thanks for the replies. The frost has not been an issue in the past, prior to roof replacement. Might be caused by exhaust fan relocation and maybe ducting was not seated properly into vent. Since there are icicles around the bathroom exhaust fan duct, might be a good place to start the moisture investigation. We had new insulation blown into the attic space, topped up the insulation to have about 20" of blown insulation in the attic. I have tried to rake the roof after heavy snow falls to help keep the eaves clear. We often get eaves ice blocked due to temperature swings, this year being one of the worst. Ridge venting was installed during the roof replacement and had a ~4" (2" on each side) gap cut @ the peak to serve the ridge venting.


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## IslandGuy (Jan 30, 2014)

Soffit vents most likely blocked by the 20" of blown insulation. Excessive moisture in the form of vapor - either clothes dryer or bathroom or even, god forbid, gas boiler or furnace leaking moisture into attic.


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## Windows on Wash (Aug 30, 2011)

+1

That is a trainwreck in process.

Get the ventilation fixed ASAP.

Get the attic dry and get the floor air sealed along with routing any moisture through the roof or through the side of the home.

Wowsers on the amount of moisture in there.


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## gregzoll (Dec 25, 2006)

Windows on Wash said:


> +1
> 
> That is a trainwreck in process.
> 
> ...


I would say so. Getting some baffles and pulling the insulation away from the eves is a good start. Also sealing any air leaks, fixing any leaky hoses for exhaust fan's, etc..


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## ParagonEx (Sep 14, 2011)

Yes as others mentioned, definitely check to see if a bathroom or even kitchen vent is venting out directly into the attic.


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## Gary in WA (Mar 11, 2009)

Photo 3; http://www.buildingscience.com/documents/insights/bsi-049-confusion-about-diffusion

And be sure the fan duct is insulated/vapor barrier; http://www.energysaversny.com/frost_-_moisture

Gary
PS. Welcome to the forums!


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## olaf (Feb 24, 2014)

*Thanks*

Thanks for the replies to my post. I went back into the attic again today and found a few things. 

1) One bathroom fan (the one in the posted picture) was not insulated and was venting right into the attic. I adjusted the duct to be IN the roof vent as well as wrapped the ducting with duct insulation and spray foamed the duct @ the roof vent. Prior to this work, I had my wife cycle the fan on/off and the air flow from the fan would stir up the blown in insulation. After the insulation and sealing work, I could not see/feel any air movement around the bathroom exhaust fan. I think this duct was the MAJOR culprit to all the frost. I do think some addition roof venting would not hurt. The ridge venting is only cut back an inch or so in several places along the ridge. I'll put in some additional venting to accompany the ridge venting we had put in when we reshingled the roof. 

2) Electrical penetration blowing air. Found 1 electrical penetration, near the attic hatch, in which you could feel the air moving up from the space below. Spray foam sealed around the penetration and could no longer feel any air movement from below.

3) Sealed up a few other small places which I could see daylight. It appears I have good soffit ventilation as when I turned off my head lamp I could see daylight in the joist spaces near the soffits.

I think I am well on my way to getting a dry attic!
Thanks!!


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## Gary in WA (Mar 11, 2009)

Glad we could help! Be sure to poly over the insulation covered ducting or moisture can still condense there.

Gary


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## TedLeger (Feb 24, 2014)

*Roof*

As the others said, there are possible soffit vents that are clogged, or something I didn't see here is that the ridge vent in itself could be clogged up. If it stays cold enough for the ice to stick, then the ridge vent in itself could be clogged. From my experience, a ridge vent that goes all the way across the roofline, and having a gable vent on each side, would still prevent moisture even if the soffit was clogged up. Do you have gable vents? At least from the picture it looks like a gable roof and not a hip.


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## JustinK (Oct 4, 2009)

How about the door going up to attic? Is it pull down stairs? Is it in living area of house? They dont seal good and can let alot of hot moist air into attic. You can get insulation tents for them.


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## olaf (Feb 24, 2014)

Thanks. No at the present time there are no gable vents installed. That is now my plan to add some gable vents to accompany the ridge venting. Currently the ridge venting is soaking wet and I do not think is providing enough venting.

The attic hatch has foam insulation surrounding the lip when the hatch sits. I have tested its 'tightness' with a feather and it does not appear to be leaking. 

Was up in the attic again today to see the drying progress and it is looking a whole bunch better than the other day. Still moist, but limited frost...


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## TedLeger (Feb 24, 2014)

*Ridge Vent*

If you have gable vents, then it would give it better air flow. Even thought the soffit would help, it doesn't give near the amount of air flow as the gable vents. Another option once you add gable vents is to put an attic fan at one of the gable vents and blow the air out of the attic. This will speed up the process of getting moisture out of the attic. Odd that there aren't any gable vents installed though. I guess it depends on the zoning codes of the area. I like seeing them either way.

Just the air moving like that will kill the moisture. Think about in the bathroom, when you take a shower and the mirror fogs up. If you turn on the vent it will clear the mirror up right away because it pulls the moisture out of the room. Same concept with the attic fan at the gable vent.


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## timetravler (Jun 30, 2014)

*Check for Vapor Barrier*

Were in the process of fixing our home, long list of things. We had a similar issue as yours, our home inspector missed the vapor barrier in the attic he said there was one but there was not. Its not an easy fix going to take me a while. So if you have not checked and still have problems this next winter or you may want to check now before winter.

It actually got much worse than the photos as the winter progressed, we ended up running the bathroom fans 24/7 to put house under negative pressure to help stop the migration of warm moist air into the attic will have it fixed before this winter.


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