Ventilation Issues

Old 03-10-06, 06:47 AM
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Ventilation Issues - not sure if this is a roof or attic question

We have a 17 yr old cape cod with cathedral ceiling in one side of house. After installing vinyl and a new roof, we've developed moisture/mold problems in the knee walls roof on the north side of the home and top attic space. We have soffits, but the insulation in knee wall is packed all the way up to the roof sheathing, & insulation in the cathedral part of the ceiling is packing almost right up to the roof sheathing, so there is basically no air flow from the soffits to the newly installed ridge vent. The mold is spotty, not all over. We've been told by an insulation person that there is no working space to put baffles between the rafters. Is there any way to open the airway between the cathedral ceiling insulation and roof, short of pulling down the ceiling drywall down or the tearing the roof off, and, if not, is there a way to vent the kneewall such as with a vent or exhaust vent/fan to provide air flow? Would a gable vent fan help draw the air out of the top portion of the attic?

Last edited by CharlotteAnn; 03-10-06 at 07:24 AM. Reason: Not sure if this is a roof or attic question
Old 03-11-06, 06:06 AM
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The proper way to address the problem is to remove the ceilings to access the rafter cavities, install required rafter venting from the knee walls to the ridge vents or the eaves to the ridge vents....then reinstall the insulation and ceiling.

Any other method will only address portions of the problem and lead to more severe damage over time.
Old 03-11-06, 03:16 PM
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I used to work for a guy who said that you couldn't get too much air into a roofing system. What you need to do is to remove the existing sheetrock and insulation, install rafter vents and new insulation, and re-sheetrock. Also, make sure that you have a ventilated soffit and a ridge vent or the rafter venting won't work. It's a lot of work but you really don't have an alternative. The existing insulation is not doing it's job as it is constantly wet from condensation.

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