condensation on inside of roof

meepscat · Sat Aug 01, 2009 1:35 pm

I have a 1976 Glenwood 14-54 mobile home. I live in northern MN. In the winter months I have condensation building up on the inside of the metal roof. It freezes to the roof until a warm day and then melts and leaks through the ceiling. There are 4 vents on the top of the roof but none on either end. I have no overhang on the sides of the roof so no vents there. There is very little room in the attic so installing vents on the ends wont work. There are no leaks in the roof, this only happens in the winter months. I am 100% positive this is condensation, I tore out the living room ceiling and seen all the frozen droplets all over. I re insulated the ceiling and put up 2 layers of 4 mil plastic taped and sealed the plastic, installed tung and groove and it is still coming through.
Please advise on a fix for this I am real desperate. I have been approved for a loan through the county but they have a lot of restrictions and they are not sure how to fix this.
help. thank you

Greg · Sat Aug 01, 2009 5:35 pm

Hi & welcome. In the situation you describe, there are two things you can do to help. More ventilation, by adding extra vents. And more insulation can never hurt, just remember that you should not totally fill the space.

I'm sure JD, and others will add their thoughts as well. Greg

meepscat · Sat Aug 01, 2009 6:36 pm

Thanks for the reply Greg. I am hopeing that the county guy will come up with some kind of answer soon. In the mean time I am trying to find ways of fixing this or at least explain to the county guy that in some way I need a new roof that has some overhang for ventalation. The top already has 4 vents but there is no air flow coming in. also there is no insulation where the 1"x2" trusses run [with the exeption of where I have replaced the insulation] From the ceiling to the roof it is open those 2 inches every truss. To reinsulate, either the roof or the ceiling has to come off and cost is a big factor here. I am on a fixed low income from SSDI. This loan is regulated and they don't seem to want to do much. Thanks again, I hope this can be resolved.

JD · Sun Aug 02, 2009 1:01 am

I am going to have to pass on this one because I have no practical experience with freezing weather. I know....poor me. But there are a lot of "lucky" members here that have dealt with this.

JD

{Post edited to say NO practical experience. duh}

Greg S · Sun Aug 02, 2009 7:55 am

More ventilation is only part of the solution. You must also stop the warm moist air from passing from inside your home into the attic space in winter. Unless you do that you will always have some condensation forming on the cold roof surface.
The only way to accomplish that is to remove your entire ceiling and install a sealed plastic vapour barrier.
You should also have a vapour barrier on all of your walls to prevent moist air from saturating your insulation inside the walls.

Financially installation of a vapour barrier may not be practical but it is the only solution to completely resolve the problem.

meepscat · Sun Aug 02, 2009 12:20 pm

Thank you Greg S, that is the type of info I need to explain to the county. If I can convince them its a heating prob I have a better chance at getting it fixed.

Brenda OH reregister · Mon Aug 03, 2009 9:15 am

would an exhaust fan like an attic fan, help, by moving the moist air out, or would the incoming outside air be wet too?

Brenda

mobilemo · Mon Aug 31, 2009 11:37 am

meepscat wrote:I have a 1976 Glenwood 14-54 mobile home. I live in northern MN. In the winter months I have condensation building up on the inside of the metal roof. It freezes to the roof until a warm day and then melts and leaks through the ceiling. There are 4 vents on the top of the roof but none on either end. I have no overhang on the sides of the roof so no vents there. There is very little room in the attic so installing vents on the ends wont work. There are no leaks in the roof, this only happens in the winter months. I am 100% positive this is condensation, I tore out the living room ceiling and seen all the frozen droplets all over. I re insulated the ceiling and put up 2 layers of 4 mil plastic taped and sealed the plastic, installed tung and groove and it is still coming through.
Please advise on a fix for this I am real desperate. I have been approved for a loan through the county but they have a lot of restrictions and they are not sure how to fix this.
help. thank you

We had the same problem. After installing extra venting, and building another secondary roof with a 60'long roof vent and 2' overhangs on the sides we still had the problem. We've torn out the ceiling, vap barrier and insulation and discovered the cardboard like stuff from the factory just over the original mobile home trusses and under the metal roof had either fallen down or deteriorated to the point where it fell down. Tough fix considering it was on top of the trusses. What we did was install roofing felt in the the places where it had deteriorated, and just shimmed up the areas where it had fallen down, then re insulated and vapour barriored it. It seems to have fixed the problem.