|Posted on Monday, March 07, 2005 - 05:26 pm: ||
We added a new addition to our 1935 hip roofed house and it has drastically altered the thermal balance of the attic space. The hip roof has slate, the addition has the faux slate. The HVAC sub installed an air handler for the FHA in the new addition attic space and my GC enclosed it to minimize the heating effect. The FHA ductwork is throughout the old and new attic space and is insulated. The old attic used to have rock wool insulation between the rafters. The GC removed this and had cellulose blown into the floor. The old attic has no ventilation. It's clear that since the renovation, the old roof is too warm now and we are having dams and leaking problems. My thought is to insulation the rafters now but should we also do something about ventilation? I'm not looking forward to having someone put soffit vents in (if it's possible). Also, what effect does gutters have on ice dams/leaks? I've heard conflicting opinions. It seems that if the gutters are iced over then the eaves would have been iced over anyway and water that is backing up will leak above that area regardless. My GC is telling me that having spacers behind the gutters will help prevent water from getting behind the fascia board. The gutters are flush against the fascia. Sorry for such a long post.
|Posted on Monday, March 07, 2005 - 05:56 pm: ||
You should have both soffit vents and roof vents for a true airflow.You might want to install passive roof vents since your house is hipped roofed and harder to install ridge and hip venting.You might try poly iso foam cut to cover the rafters to help keep out unwanted heat too.
The fact that your gutters are tight against the fascias isn't a problem-but gutters can lock in snow and ice making it more difficult for the slate roof to shed its snow load after a storm and therefore start the damming process.
Because your roof is hipped it doesn't shed its snow as quickly as a gable roof anyway.
Does the new roof intersect the old roof to form valleys?Did you ever experience damming before?Have you had unusually heavy snowfall this season?