Need some help here. All this winter we've had a lot of condensation and even ice on the inside of our windows. Tonight i went up into our attic after my wife mentioned she was in there yesterday and saw a lot of water on the roof and on tops of the boxes we have stored up there.

When i went up tonight what I saw was a very thin layer of ice all across the north side of the attic and some on west, south side was fine.

We also have on the first floor north west corner baseboard signs of water damage, very slight.

I can tell you my wife runs a humidifier (one on wheels) in addition to our humidifier set w/ the furnace. We have one 55 gal fish tank, a 20 gal fish tank, and a small frog tank w/ some water in it as well. Thinking this is a humidity issue but not sure how to verify / proceed.

Attaching pictures i took.

1st picture is North facing
2nd N by NW
3rd Straight Up
4th Straigh Up
5ht South (though this also had water yesterday)
6th N by NE

 

I'm guessing since you've walked around up there, you are sure no plumbing stack, dryer venting, bathroom venting, etc is exhausting into the attic right? I guess that's probably the first thing you made sure of.

 

Assuming you don't have the major issues already mentioned regarding air leakage paths I would suspect that a high vapor drive can be somewhat responsible for the moisture issues you see.

I noticed you have blown-in fiberglass insulation probably without a vapor diffusion retarder other than the interior paint film. You also have a hip roof that limits the roofline available for ridge vent application.

What is your heat system? Assuming hot air, is there any duct work in the attic? Is there sufficient clearance for ventilation at the point where the insulation is over the top plate of your exterior walls? Does your furnace humidifier have automatic controls to coordinate with outdoor temperatures? Do you know what the indoor relative humidity is? How high is the ridge of your attic from the ceiling plane? What have night time temperatures been in the last few weeks? Would you classify your basement as damp?

There are a long list of considerations.

 

Any soffit vents?
Are they blocked with insulation?
How much insulation is up there?
You area called for around R50 which would be about 12".

 

Turn off the humidifiers. Air seal between the house and the attic. And get the attiv ventilation working.

All previous questions will help determine how best to get these repairs done.

The photo of the ridge where the sheathing has a gap, is there a ridge vent on the outside? It looks like it may have not been opened to the inside.

Bud

 

Gonna answer what i can now. Check the other stuff and post on that when i know.


1) Nothing exhausting into the attic, everything vents outside.
2) Heating system is hot air - 2 year old Bryant HVAC
3) I don't believe there is duct work in attic but I will double check
4) How do i check to see if there is sufficient clearance for ventilation at the point where the insulation is over the top plate of my exterior walls? - I do know that there are these plastic rectangle plate like things inbetween each wood 2x4 where the roof meets the floor and i can see light there when it's dark.
5)The furnace humidifier does not have automatic controls. There are two manual dials
6) No idea on indoor relative humidity. How can i check?
7) Stumped on how high the ridge of the attic is from ceiling plane... how do i check that?
8) I live in the NW suburbs of Chicago. It's been a very cold winter to say the least.
9) I would not classify our basement as damp. Though there are a few slight cracks in the foundation that show some leakage but no standing water at all on the floor (other than when the humidifier box on the HVAC drips)

Oh also I think someone asked about insulation in the attic. There is blown insulation over top of 'regular' insulation.

 

Humidifiers were turned off yesterday. Hoping that helps a bit but how soon would i see the difference?

 

If your attic ventilation is working, the cold outside air is very dry and will remove most of what you see for frost in a day or two. Best if it evaporates (sublimes) as opposed to melting and dripping.

There are relatively inexpensive humidity meters, may not be terribly accurate, but will still tell you when the RH is going up or down. RH is a good number to understand as it relates to comfort. Where too much is not good you need to find out how low you can tolerate it.
Here is a RH calculator to play with. Calculate Temperature, Dewpoint, or Relative Humidity

I'll let Joe and Calvert respond to the other answers provided.

Bud

 

Sorry for the slow delay in getting answers to the outstanding questions. We recently took in a 2 year old foster girl (on top of the 2 kids we have and the other 9 month old foster son - did i fail to mention we have a puppy too ). Needless to say it's been crazy around here.. but fun!

So all i have for now is that 99% of the window condensation is gone. Poof, gone. I went up into the attic yesterday and the frost is still there, but the temps around here have not gone up (if anything they've gone down) since my post. So keeping an eye on that.

Trying to get my hands on a relative humidity gauge. If i can break away today I'll try and hit up Menards or HomeDepot and pick one up.

 

The missing condensation on the windows tells you the RH has gone way down. As for the frost in the attic, you need to identify where and how much ventilation is up there. Being that the frost is still there I would assume there is very little air exchange.

Bud