Frozen condensation in attic now that it's really cold

[iamwiz82]

Background: New roof this August, ridge vent running the entire length of the house, also lots of soffit vents.

I went up in the attic this morning this morning because I noticed a spot of water on a vaulted wall. It turns out that the entire attic is covered in a very thin layer of frozen condensation. The humidity in the house has been about 35-40% consistently as of late, though I did just get a humidifier because my throat was not dealing well with the dryness. We had it running all night and it filled the bedroom with approximately 1.5 gallons of water.

Think that was enough to cause all the frozen condensation there? That is where a majority of it sits in the attic. The wall that I noticed was sweating is the bedroom wall, as well.

 

[olds]

Mold

 

[funboy6942]

Thats a sign of poor insulation and can start all kinds of future problems such as mold, rotting wood, etc. Shouldnt be ANY condensation at all inside your home, I would think.

 

[Thorny]

How well is your attic insulated?

 

[Minerva]

Do you have any unvented gas heaters running?

They will add a LOT of moisture to the air. How accurate is your hygrometer? Get a sling psychrometer and a psychrometric chart to determine relative humidiy and dewpoint correctly. Install a turbo ventilator.

 

[iamwiz82]

Originally posted by: Thorny
How well is your attic insulated?

12" of blown and 12" of pink on top of that

 

[olds]

Originally posted by: iamwiz82

Originally posted by: Thorny
How well is your attic insulated?

12" of blown and 12" of pink on top of that

:laugh:

 

[iamwiz82]

Originally posted by: Minerva
Do you have any unvented gas heaters running?

They will add a LOT of moisture to the air. How accurate is your hygrometer? Get a sling psychrometer and a psychrometric chart to determine relative humidiy and dewpoint correctly. Install a turbo ventilator.

We already have a power vent, two actually. The house definately has enough flow up there. There's never been any sign of inadequate, actually.

Could it be so cold (It's around 0F, right now) that the vents don't have time to work?

I think the hydrometer is pretty acurate, I'd say within a couple of percent. Up there it's around 45%.

EDIT: We had been using a kerosene heater when power was lost a few weeks ago.

 

[iamwiz82]

Originally posted by: oldsmoboat

Originally posted by: iamwiz82

Originally posted by: Thorny
How well is your attic insulated?

12" of blown and 12" of pink on top of that

:laugh:

Woah, I didn't mean for it to come out like that!

 

[funboy6942]

Maybe you have too much insulation?

 

[Minerva]

Good lord turn back the humidifier! At 0F you have WAY too much moisture in the air.

Hydrometer? What's the specific gravity of the pink stuff? :laugh:

Sorry, could not resist!

 

[iamwiz82]

Originally posted by: Minerva
Good lord turn back the humidifier! At 0F you have WAY too much moisture in the air.

Hydrometer? What's the specific gravity of the pink stuff? :laugh:

Sorry, could not resist!

Type-o, but I do have one of each

 

[funboy6942]

Article on Attic Condensation and causes.

 

[iamwiz82]

I'm thinking that it's because of the sudden really cold weather. It's been in the upper 20s until yesterday.

 

[drum]

do you live in International Falls, MN where it's 45 below? :shocked:

 

[FoBoT]

when the outside temperature drops, you have to lower your inside humidity

 

[Jawo]

Originally posted by: iamwiz82
I'm thinking that it's because of the sudden really cold weather. It's been in the upper 20s until yesterday.

That could be the problem, with the drastic drop in temperature the dewpoint will drop as well.

Dewpoint Calculator

At 20F with 45% humidity, the dewpoint is 8F degrees, so the condensation probably froze

 

[iamwiz82]

Originally posted by: FoBoT
when the outside temperature drops, you have to lower your inside humidity

Blame Lola, I was not home :laugh:

 

[MX2]

I have the same problem

 

[DrPizza]

I wouldn't worry a ton about it, unless the frost was really thick... the temperature dropped like a rock. If it remains that way throughout much of the winter, then, I'd worry.


edit: I'd also check that article someone posted somewhere above... I was thinking about your power vents... How are they set? Only to come on when it's 140 degrees in the attic? Perhaps the insulation is installed incorrectly (facing on the wrong side)? There are a few things that would cause it.

 

[iamwiz82]

Originally posted by: DrPizza
I wouldn't worry a ton about it, unless the frost was really thick... the temperature dropped like a rock. If it remains that way throughout much of the winter, then, I'd worry.


edit: I'd also check that article someone posted somewhere above... I was thinking about your power vents... How are they set? Only to come on when it's 140 degrees in the attic? Perhaps the insulation is installed incorrectly (facing on the wrong side)? There are a few things that would cause it.

The vents don't have humidistats. I was looking online to buy a couple that are both temperature and humidity dependant.

The front itself it thin, except on the nails from the roof, which have more frost on them.

I've turned off the humidifier and the humidity up there has dropped to 40% already.

 

[MikeyIs4Dcats]

is the condensation on the underside of the roof sheathing or on the insulation?

 

[iamwiz82]

Underside of the sheathing.

 

[MikeyIs4Dcats]

Originally posted by: iamwiz82
Underside of the sheathing.

then the attic is staying warmer than outside, which is fairly common. Are you certain the ridge vent is properly installed? Are trhe soffit vents free to circulate, trhat is, did they use vent liner to maintain air routes from the eaves past the attic insulation?

 

[Strk]

Originally posted by: iamwiz82
Underside of the sheathing.

Going by your profile, I'm assuming there's a bit of snow. My guess would be ice is building up and the roof isn't venting properly -- causing the ice to melt and go under the shingles (what was used as underlayment?)