[passat]

I have a soffit vent on the west side of my house which is approx. 1' x 2' that is just an opening in the soffit covered with screen. FIY there are 5 soffit vents in total, 3 more like this one, another one on the west, 1 on the east and 1 on the south, as well as a new 11" x 18" (louver and screen) one on the east side and a 30' continuous one on the south; in addition there are 11 roof vents. I live in Ohio and it's colder than !#@ right now.

Here's my problem: Directly inside of the vent first mentioned, moisture formed on the ceiling in a pattern the same size as the vent. This occurred in the winter during cold weather and I assumed it was because of inadequate insulation in that area resulting in cold air on the other side of a warm ceiling. I checked the attic and found that there was only 4" to 5" of old settled insulation in the attic. As the roof is 4/12 pitch with 2' eaves and no flooring I haven't and can't physically check the area in question.

I did contract to have an additiona 10" of insulation blown in the whole attic with air chutes installed for proper ventilation. On 11/22/04 when the installers came they talked me into letting them put bats of insulation around the perimeter of the attic which would retain the blown in insulation and provide vent space rather than installing air chutes. It made sense to me, so I agreed that as long it worked it was OK with me and that's what they did.

A few days after the job was completed it turned cold and the condensition was worse. Not only was it in they same area but it was spread out along both outside walls of that room but it also appeared inside the similar vent on the east side and the other one on the west side.

I called them back out and a different crew checked and advised that the problem occurred because there was little or no insulation under where they had put the bats and the air was blowing in under them and spreading around the ceiling perimeter under the bats where there was insufficient insulation. They said the corrected this by cutting the bats where necessary and putting them between the joists, installing air chutes and blowing additional insulation over them.

Well it's cold again and the condensation is back in the original area and if anything it is worse. Now they tell me that the insulation is not the problem and there is nothing else they can do.

They owner has agreed to come out himself to see if he can make any suggestions as to how I might correct the problem but I would like to here from some of you before he does.

To me it's got to be cold air on warm ceiling. If I'm wrong, give me a clue.

[labman]

It seems to me that builders go out of their way to leave too little space between the ceiling and roof sheathing to allow for enough insulation and air circulation. However, I am sure you house is no worse that many others, and most houses seem to work better. I wonder if poor side wall insulation could be contributing to the problem. If the side walls have blown in insulation, and it has settled, you could be losing heat out the wall near the ceiling too. I am sure your friendly contractor would be happy to blow in some more.

[passat]

There is no condensation on the wall (only what runs down in streaks from the ceiling). It starts at the junction of the wall and ceiling and extends out about 16" to 18" on the ceiling.

I doubt if there is any insulation in the walls at all. They were built in the 50's and are brick over insulation board, with 2 x 4's, with 1/2" drywall which has (yes that's right) 1/2" of plaster over the drywall.

[tommytman]

What kind of roof vents do you have (11 of them)??

[passat]

Just the standard square, low profile, aluminum non powered vents. NOT RIDGE VENTS.

[willywild]

Hi Passat. I have the same problem. I was told a ventilation problem existed or lack of insulation. First winter(2007-2008) in the house no problem. Next year I discovered 3 condensation spots very close to outside wall when weather turned cold. Drips also ran down wall.(master bedroom) After a lot of advice I decided to let the mould guys go up and add baffles and stuff insulation where they could.(2009-2010) Of course it got mild and had to wait for cold weather to return. 1 problem area cleared but 2 smaller spots were created. Eventually problem seemed to go away. Decided to add insulation. Went from approx R-12 to R-50. This year 2 spots are gone but 2 of the same have returned. Even though aluminum soffits have plywood underneath I was told ventilation was great. One last thing to check is to remove soffit and make sure no gap exists between wall and pitch of roof. Remove soffit and look or put your hands up inside the soffit and you will see or feel the header. If you have a gap you can add a piece of foam insulation. I will try this next.
Will