VENTILATION BLOCKED
Did you know that you can defeat any thermal advantage that could be gained when you add insulation to your attic if you don’t have the attic properly ventilated?
Insulation and ventilation go hand in hand when looking to the thermal comfort of your structure. Thermal comfort involves not only the temperature of the interior, but also the humidity level. That is where ventilation plays a key role. In order for your attic space to function properly insulation and ventilation must work in harmony.
Ventilation
During summer months hot air can build up in an unventilated attic space. Your attic becomes a hot box, like an oven, as the sun’s rays bake your roof’s surface. Once the sun sets the super-heated air that has accumulated over the day in your attic will radiate into the structure below, increasing the energy needed by an air conditioning system to keep your home comfortable.
In the winter months heat rising from your building’s interior will radiate through the the ceiling in to the attic space and warm the roof deck. This will begin to melt any accumulated snow on the roof. As that melted snow runs down the roof, reaching the colder surfaces along the eave it will refreeze, creating ice dams. In turn ice dams will cause water to back up under your roofing materials and creating leaks into your structure. Also, as the melted snow runs down the roof slope, the moisture of your building’s interior air can condense on the support beams and roof’s wooden sheathing inside your attic, creating the potential for rotting and mold.
If the average family of four generates two to four gallons of moisture in their homes with their daily activities of living every day, imagine how much moisture is generated in more populated structures. Ventilation allows air and moisture to move out of the interior of your dwelling creating healthier living conditions.
So while it may seem odd to provide a blanket of insulation in your building to preserve the interior warmth while at the same time allowing cold winter air to flow over that insulation, when done correctly, it is the key to a durable, healthy and energy-efficient structure.
Seal Any Bypass
In relationship to a building, a bypass is an open area within its walls or ceiling that allow the passage of air from a conditioned area to the attic. Bypasses are commonly found around ceiling light fixtures, chimneys, heat ducts, exhaust fans, plumbing, wiring outlets, and soffits.
When air is able to flow from one part of a building to another the moisture within it travels through your structure as well. When this warm moist air reaches the attic it can contribute to the formation of ice dams, rotted wood framing and roof decking, and reduce the effectiveness of your insulation.
BEI Exterior Maintenance will first seal these bypasses when updating your building’s insulation and ventilation needs in order to keep everyone comfortable and healthy. Contact BEI Exterior Maintenance and talk to one of our consultants about your insulation and ventilation needs.
Insulation
Having the amount of insulation your structure needs at the right R-value is a primary component in maintaining your home’s thermal comfort. The “R” in R-value is the resistance to heat flow from conditioned space to un-conditioned space, the very thing that insulation is put in place to do. Having too little insulation, insulation that is inconsistently placed, or compacted insulation can create problems for your attic. Too much insulation in wrong areas of your attic can also create problems by restricting ventilation.
If too much insulation is in the wrong area of your attic it will make your attic colder or warmer, but will not restrict moist air from leaking into the attic. During winter months as warm air rises from your building’s interior and mixes with the cold air in your attic the moisture in that air can condense on the underside of your roof deck before being vented out. This condensation, when it melts, can cause damage to the wood framing members and saturate your insulation greatly reducing its functionality.
