Insulating and Venting When There is No Roof Soffit
May 21, 2016
In most residential homes, the soffit (and associated vents) is the structural part of the roof that "hangs over" the side of the home. The principle behind soffits is to allow air to circulate in and around the attic. However, not all homes (especially older homes) have overhangs, and therefore they have no soffits. It could be said that this makes for an easier insulation project in the attic, because there's no worry about inadvertently covering over soffit vents with insulation material. However, these scenarios require another solution to address ventilation. For homes without soffits (or narrow ones), the attic can still be very effectively insulated. This is accomplished by installing insulation to include all of the corners, angles and wedges where the attic slope meets the attic floor. Clearly, the required amount of R-Value must be determined to ensure that appropriate thermal insulation is installed. In terms of product, batt insulation will be different than blown insulation, which will be different than spray polyurethane foam insulation. Aside from the technical aspects of insulating and venting an attic without a soffit, this is a project that requires both experience and expertise. To begin with, the attic must be sealed to make the space airtight, and to ensure that there is no air leakage. For professional installation contractors, sealing is key in assuring peak performance for the insulation that will be installed. And since fiberglass/cellulose insulation itself does not prevent air movement, no installation is complete without the sealing effects of spray foam. For many reasons, a DIY approach to this type of attic insulation isn't recommended. The benefit of an expert install is threefold: the attic is professionally assessed to determine needs; product is selected based on those specific needs; and installation is expedited to assure optimum long-term performance. When it comes to product selection, an expert installer can also be an advantage in selecting the product (or combination of products) that will best suit the project needs. Beyond the insulation, attic air sealing is absolutely critical to the "system". Without adequate air sealing, there is a tendency for conditioned air from the house to escape into the attic space - and that will impact the home's energy efficiency, as well as energy consumption. This is a perfect scenario for wasting heat during the winter and air conditioning during the summer. At the same time, as the HVAC system works to compensate for the energy wastage, seasonal utility bills begin to grow out of control. Properly ventilating an attic, when there is no built-in soffit, can be a challenge. But for experts, a well-designed system will ventilate effectively, while complementing the installed insulation - it all has to work in tandem. Short of suggesting structural changes, or a new soffit, a reputable insulation contractor will make sure to create a "system" that will be well sealed, well ventilated, and well insulated. They key is to do it right the first time, without taking any shortcuts. In southern Ontario, and throughout the province, Great Northern Insulation installs efficient attic systems that incorporate both insulation and ventilation. All products and installations are fully warrantied, and customer satisfaction is assured on every project.