Cape Cod House Attic Ventilation

Special venting or packed hot roof problems for cape cod roofs.

Cape cod house attic ventilation.

Cape cod roofs present a special problem in that in the usual cape design there is a lower attic knee wall enclosing what amounts to a low attic followed by the equivalent of a cathedral ceiling over the middle section of the roof often penetrated by dormers when the second floor of the cape cod is designed to be occupied followed again by an attic design for the upper third of the roof. It s good that you have an air barrier on the attic side of the knee walls over the insulation. Roofers use a circular saw to cut a long slot along the roof ridge if there isn t one then cover it with a plastic flap as shown or a flexible vinyl matrix. The slopes are vented by the air gap between insulation and roof sheathing.

Old school roof vents which look like rectangles on the roof work pretty well too. In an ideal world we install soffit vents as intakes make sure the slopes can breathe with ventilation baffles and exhaust through a ridge vent. The cool vent nailbase system is installed over the old roof deck after the shingles are removed. Usually the issue with cape cod style homes lies in the fact that warm air gets caught in the corners of low ceilings.

When you allow the air from the outside to enter your attic you need to make sure that the cold or hot air which gets generated by your house exits the attic. Openings along the sides allow air out of the attic cooling the space and lowering your air conditioning bill. Check our ventilation page for more info. Account for codes and safety photo by casey dunn.

Intake vents located at the lowest part of the roof under the eaves allow cool. Yes behind kneewalls there is vented attic spaces. Venting prolongs the life of the roof. Ventilating knee wall attics is challenging.

How to heat cool a cape cod style house 1. What we do we create 1 opening on both sides of the ridge cutting the roof boards plywood on the very peak. The existing attic insulation is left in place when a cool vent roofing system is installed. The thickness of the polyiso foam is customized on each project and can increase the existing r value from anywhere between r 6 to r 25.

Outside air needs to be able to come in through the soffit vents and travel along the underside of the roof sheathing so there can t be blockages up to and out the ridge vent. While the house should be tight the attic should breathe to allow excess heat and moisture out of the house. They are vented by small vents down low used as intake vents 2 on east end of house and 2 on west end of house and a couple of rectangle vents up close to the peak used as exhaust vents. The upstairs area is very close to the roof and has little or no attic barrier meaning the sun s heat easily enters the interior.

Every attic is different but a few established norms and practices will guide your renovation.