Winter Condensation in Attic

[Sp]

Hi,

We bought a home in June, and came to find substantial mold problems on it's existing roof decking back in June. We have since ripped off all the roofing and decking, bleached all the timbers, and redone it all. A costly problem - but thankfully we were able to prove negligence on the inspector's part.

During the redo, we added many more soffit vents, as well as a very good ridge vent for the roof's duration.

Anyhow, it is now winter where we live and last night I went into the attic, and there is condensation on the decking !!!! The new ventialtion and everything noticeably seems to be working well, but I can not figure out how the condensation has developed. All bath vents are vented outside, and there really is no other access into the attic.

Any thoughts and ideas are very much appreciated. Thanks.

[Hube]

SP; Welcome to the forum. You made the right decision when you added the extra soffits and ridge vents, but is there still a "mathematical" LACK of these vents? Building code suggests a MINIMUM of 1 sq. ft. of free unobstructed ventilating area for each 300 sq. ft of insulated ceiling area. Also this condensation can also be caused by inadequate insulation R value) and/or a lack of a properly sealed Vapor Barrier. Do any of these fit your situation? Hube

[Jimmer]

Sp,

Depending on the humidity outside and how quickly the temperature drops some condensation can be normal. We had a couple of days of rain and warm temps earlier this winter and then overnight the temp dropped from 50 to 10 degrees? I noticed ice in the attic of several houses after that. As the weather has stayed cold and dry it has gotten better.

Jim

'Just a handyman trying to help'

[Sp]

Hi Hube and Jimmer,

Thank you very much for your responses and help

I do believe that our ventilation should be adequate, but I will definately investigate further. Upon examining the R value and insulation, I am thinking maybe it is letting too much heat up through it.

I installed an R 19 6" pink Owens Corning.

http://owenscorning.com/around/insulation/products/pfgi.asp

The spec's are

Application(s):
Additional attic insulation
Crawlspace (Heated)
Finished attic
Basement walls
Exterior walls
Under floors

Length: 93" Width: 15" or 23" Thickness: 6 1/4"
Sq. ft.: 77.5 or 118.8
Product options: Unfaced Kraft faced

It did not have a vapor barrier like I am used to (ie meaning a paper side to it), but on one side it had like a glazing I had guessed was the vapor "seal" on it. I faced that down towards the living space. I am now a little scared that this may have not had a seal on it.

Any other ideas or thoughts are extremely appreciated Thanks again very much !!!