Insulating and Ventilating a Cape Cod House
Insulating and ventilating "Cape Cod" or 1-story houses can be very challenging. Anyone who has lived in one of these types of houses knows how uncomfortable they can be in both the summer and winter months. The problems associated with these homes are a result of poor architectural design and not improper installation of the roofing or insulation.
Contractor's and Homeowners have two options when addressing the insulation and ventilation deficiencies of a Cape Cod. They can adequately ventilate or insulate the house, but not both. The illustration below shows the scenario when proper ventilation is achieved. In order for air to flow unobstructed from the eaves to ridge, a void in the thermal boundary is created. This will cause heat to escape in the winter and hot air from the roof surface to enter the living space in the summer.
The next illustration is an example of the airflow problem that arises when the maximum insulation is installed. This creates three unconnected areas of attic space that cannot be ventilated in a conventional manner. It is worth noting that roof exhaust vents are not designed to be installed on lower levels of the roof. As water travels from higher to lower roof levels the volume and velocity of the water increases. Ridge vents can only be installed at the peak and louvers are designed to be installed within three feet from the ridge to ensure they will remain water tight.
The Cool-Vent by Hunter Panels is a product that is usually installed on commercial steep- sloped roofing systems such as schools or churches. This product is also the best solution for effectively insulating the Cape Cod style house.
Cool-Vent, a rigid insulation panel composed of polyisocyanurate foam core from Hunter Panels, is manufactured as a ventilated nailbase roof insulation panel. This quality steep-slope insulation board offers sustainable thermal insulating characteristics while also allowing air circulation within the roof assembly. A standard 1-inch air space permits airflow in all directions to give improved cooling and ventilation; this ventilation space helps reduce moisture vapor and heat build-up.
Cool-Vent extends the life of your roofing system by the nature of its design: Its polyisocyanurate insulation base provides the highest R-value per inch of any insulation panel.
The Cool-Vent is a 4 Ft by 8 Ft composite insulation panel consisting of three parts - wood spacers are secured to Polyiso Foam Insulation and a Wood Substrate. The gap between the insulation and wood substrate allows air to ventilate the roof deck while the insulation provides the house with a uniform thermal boundary.
The Cool-Vent nailbase system is installed over the old roof deck after the shingles are removed. 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.
The Cool-Vent installation increases the height of the roof deck by several inches. In most cases, the fascia and trim boards need to be re-installed due to the change in the roof deck.
For more information on Cool-Vent roof system installation by Deer Park Roofing click here.