first of all, i live in new york state. i have water leaking into our 1 year old home with a metal roof(vertical panel). the front roof is 10/12 pitch with an 8' covered porch,open, non heated.The roof is rafter stlye 2x12 with 2x4 perlins and the metal attached to the perlins. inside the ceilings are vaulted with rafter mates for ventilation and 12" of insulation, and t&g ceiling. The rafter mates run from the peek to the front wall of the house. The ceiling over the porch has no insulation and plenty of ventilation to go to the peek and out. over the porch the metal is staying cold and no condensation occurs, but over the house i'm loosing heat and getting insulation. I can only see up about 10' and i can see the moisture on the back side of the metal. I am going to extend the rafter mates further out over the porch and add more insulation at the front of the house. any other suggestions on this complex problem would be greatly appreciated.
Guest User
2004-11-14 21:12:04.000000
Darin,
Most quality manufacturers of this type of metal roofing would not recommend its installation over purlins for residential applications. I am sorry to have to tell you that.
I am assuming that the rafter mates are in place between all trusses and also that they are leading from soffit vents (intake) up to a ridge vent (exhaust).
I am also assuming that the roof has been checked to make sure that there are no leaks present.
Are there any sources of excessive moisture inside the home which could be controlled -- lots of house plants, ventless gas stove, humidifier, damp or wet basement or crawl, etc. Are all plumbing and exhaust fan and dryer vents vented to the outside?
Was there a vapor / air barrier placed behind the T & G celings?
Guest User
2004-11-15 13:28:38.000000
Thanks for the fast response. The insulation is in between the rafters and then the perlins are on top of the rafters. Everything there was done right. I do however have to extend the rafter mates all the way to the intake(vents) even though they are into the covered porch, with lots of cool air. After reading all your posts and your comments " condensation occurs when warm air meets cold metal" the light bulb came on! Last night i did descover i'm loosing heat fron the front wall where the ceiling ties in, lack or inproper insulation. Thanks for the help, Darin
Guest User
2004-11-15 19:58:13.000000
I have recently purchased land with a building that has a metal room (vertical slat). Inside there is a dropped ceiling in part of the building. There is no heat or air installed as yet. I recently went into the building one early morning and saw condensation collected on the inside metal roof and it was dripping down onto the floor. I am concerned this may be happening up out of sight in the finished roof part. I am needing advice as to what to install to correct this problem. I plan to use the building for storage and a resale shop. Please respond.
Guest User
2004-11-27 20:30:51.000000
I have an old metal roof with several different pitches. The almost flat roof over the bathroom has interior mold in the ceiling. The bathroom does not have an exhust fan. Would adding an exhust fan to the bathroom correct this problem or is there another way to get air circulating on an almost flat roof. I am considering replacing the entire roof with metal roof, but I want to make sure I have solved all the ventation problems first.
Thanks - Woody
Guest User
2004-11-29 11:43:10.000000
Mold in this case appears to be the result of recurring condensation. Condensation basically occurs when warm moist air hits a cool surface.
Yes, an exhaust fan vented to the outside will help. If this does not resolve the issue entirely, though, you will need to look at having some insulation added above the ceiling and, at that time, I would suggest an air barrier between the ceiling and the insulation.
Guest User
2004-11-29 21:52:54.000000
It sounds like you have a basic building as if you can see the underside of the metal roofing, then there is no insulation or air barrier installed. If it is happenig on the exposed shop side it may as well be happening over the suspended ceiling portion as well. There are specific requirements in the building code regarding this and I would suggest engaging the services of an engineer to review and advise on what improvements need to me made befor you significantly change the way the building is used.
