Q. We built a custom home for a client in west Michigan a couple of years ago, and the home has had problems with ice ever since. It's a 1,450-square-foot ranch with cathedral ceilings and many can lights throughout. We used blown fiberglass insulation in the ceiling assemblies. From the beginning, the can lights (IC-rated) overheated and tripped their thermal-protection breakers. We finally resorted to pulling the insulation away from the housing of the can lights so they TAs a result, the heat from these lights now warms up the roof and has created a horrible ice problem instead. Last fall we even added four pot vents to the back of the roof in addition to the soffit-to-ridge venting. The homeowner called to report that the pot vents have improved the situation but not completely. I drive by this home frequently and see ice buildup there while other homes in the area are ice free. More
Q: I have been asked to determine the cause of black shadow marks on a cathedral ceiling in a new home. The black marks correspond to the bottom sections of the rafters, near where the rafters meet the wall. The black shadows do not resemble stains from water leaks. There is a gas fireplace on one of the outside walls; the fireplace has been tested for leakage, and it checked out fine. The owner burns a large candle, which sits on the fireplace mantle. Could the ceiling shadows be caused by soot from the candle? More
Does a shed roof addition need collar ties to restrain the outward thrust of the... More
It’s difficult to achieve a high R-value in a cathedral ceiling while preserving... More
Unvented roofs in northern climates are prone to ice buildup, but how do you ventilate a valley or hip rafter in a cathedral ceiling? And what do you do at a skylight, where the headers block the vent chutes? A snow-country builder describes the venting methods that have worked for him at these and other tricky spots. More
Q: After my electrician finished rough wiring the last house I built, I noticed that the Romex (NM) wire he used seemed to have a thinner profile, and the individual wires seemed smaller in diameter than what I was used to. Is the copper wire (or the insulation) getting smaller, or is it just my imagination? More
Q: The house I’m building has a cathedral ceiling framed with wood I-joists, continuous ventilation at the soffit, and a continuous ridge vent. The ceiling inside will be T&G pine. I plan to use R-38 Kraft-faced fiberglass batts (which will allow a 1 1/2-inch air space between the roof sheathing and the batts), and would like to apply Tyvek housewrap over the Kraft-faced batts. However, I’m concerned that moisture will accumulate between the batts and the Tyvek. If moisture accumulation isn’t a problem, does it matter which face of the Tyvek is exposed to the room? More
Airtight, well-ventilated cathedral ceiling More
