I have a 500 sq ft cabin in NC with 2x4 rafters.The ceiling is insulated,unvented and is finished with 1980’s style panelling.The problem is at the ridge,judging by the discoloration of the panelling.I’m open to all options,including dropping the ceiling to 8ft,sheetrocking the existing,etc…I prefer to leave it as a cathedral.I’ve been told that using closed cell foam insulation would solve the problem.It’s expensive,but if it’ll work I’m open to that option.The home is unoccupied 98% of the time and is not climate controlled during that period.There’s no visible signs of mold in the house,what’s under the panelling will soon be discovered.Any help with this issue would be appreciated.
Does the ceiling go up along the rafters or is it otherwise framed?
Yep,ceiling goes along the rafters.I appreciate the advice!
Get some pictures up here.
You could either add a full ventilation system. I.E. soffit vent and ridge vent. IF there is adequate room for the free flowing of air above the insulation.
Or as you mentioned about building a drop ceiling and changing the whole setup. I think you should be able to find a solution that would be cheaper then framing a whole new ceiling. Because you still need to remove the paneling, insulate the new ceiling and still need to add the appropriate vents.
The property is a couple hours away.I should be going over within a week or two and I’ll take some pics.
When I first discovered condensation,I walked into a cool 50 degree house around 7am.By 10 am with the sun shining bright on the roof,the temp warmed to about 75 in the house.I just happed to notice a couple drops of water hit the floor.When I looked up at the ceiling,I noticed the condensation running almost the entire length of the house (30 ft) along the 2x6 partially exposed ridge(about 1/2 inch exposure).The panelling butts up to the ridge.
I’ll post some pics the first chance I get.I just spoke a local company,who suggested a ridge and soffit vents.
That sounds like the easiest way to go. Just make sure you have either soffit venting or go with DCI smartvent if needed.
If the condensation is on the inside, I doubt that venting the ridge would do you any good.
Here’s what I have seen in various similar situations: The ambient temperatures are rising along with relative humidity, and your unconditioned building is cooler than the surrounding air. When the warmer moist air contacts the cooler building, you get water condensing on the cooler surfaces.
The solution was to ventilate or condition the air space.
Any other work being done in the home? Skim coat plaster, gypcrete floors? Seems like an awful lot of condensation.
I see this problem a lot. Most of the time I just see mold up at the ridge in cathederal ceilings, but I have seen condensation a few times.
It’s a seriuos problem with the design, when you have warm moist air up there.
On one metal roof I fixed the condensation problem by taking the ridge cap off and filling the cavity with batt insulation, which removed the air in contact with the back side of the metal roof.
Here are a few ideas that you might try:
You might try adding the ridge vent and soffit vents idea first as that is probably the lest expensive. Can you add a ridge vent with the ridge beam right there and will there be air circulation?
Add more insulation directly under the roofdeck so that no air is in contact with the underside of the roof deck.If you have a metal roof, take the panels off and add 2 or 3" thick vinyl faced batt insulation and put the same metal roof panels back.
Heat the inside air which lowers the dew point.
Lower the inside humidity with a dehumidifier, or find out the sorce of the humidity and work on that.
Install ceiling fans that blow air upward to increase circulation.
I dropped off my dehumidifier to a neighbor working in the local area.He’s going to run it,as well as the ceiling fan in the clockwise motion to circulate the air.The weather will be perfect for condensation to form in the next few days,so we’ll see if that remedies the problem and take it from there…
AaronB and others,here’s a few pics.I went over yesterday,ran the ceiling fan and dehumidifier,with no heating or ac and when I left,no condensation!It’s running 24/7 until they start removing the panelling,which they will hopefully do this week.The last pic is an unisulated section above the bathroom.It gives you an idea of the construction.