The necessity of sealing your attic, before adding fresh attic insulation:
Would you re-paint your car, without first washing the dirt off of it? Would you buy a sleeping bag, knowing that the zipper didn’t work? Of course not!
Uncontrolled air movement through the shell of your home is THE major source of energy inefficiency. Uncontrolled air infiltration is the proper term for this problem, and it’s a BIG DEAL that has to be addressed if you want your home truly comfortable, and if you want your indoor air quality truly healthy.
So, what is the shell of your home? Simply put, the shell (or also called the envelope) of your home is the surface that separates the conditioned air (living environment) from the unconditioned air (atmosphere).
For a one-level ranch home, the shell consists of the four perimeter walls, the floor, and the ceiling. For multi-floor structures, the shell is basically the same: the perimeter walls, the uppermost ceiling, and the lowermost floor, that contain the conditioned space.
For a home on an unconditioned, unfinished basement, the shell does not include the basement.
Revolving Doors
Every house has pressure inside of the shell. Think of this pressure as horsepower. This pressure is called “the Stack Effect”. The taller the structure, the stronger the stack effect. The stack effect also increases as temperatures grow in contrast from the space inside the structure with that outside the structure. Stack effect is why they invented revolving doors for tall buildings; the pressure was so strong, you could not open the doors on the lower level!
The Solution
As uncontrolled air infiltration enters your home, fueled from the stack effect, it brings humidity, dust, allergens, and outside temperatures (creating drafts). You may ask yourself, ‘So I need new windows and doors, right?’
Not necessarily! In fact, rarely are windows and doors the real problem. The horizontal surfaces of your shell experience far greater pressures than do the vertical (wall) surfaces.
When we seal a home (sometimes called ‘air sealing’), we focus on the uppermost and lowest horizontal planes of the shell. And we get BIG results! And our clients become very happy!
Think about every hole in your floor and ceiling: HVAC vents, ceiling lights & fans, holes for wires, pipes, vents, and hot flues. Chases (or channels) are framed into your house to allow services to pass through the levels of your home. And don’t forget the pulldown attic stair unit. Add all of these areas up, and the negative effect from this uncontrolled air infiltration is equivalent to having the front and back door jarred open year around!
The Secret for Success
Your wise investment for “more attic insulation” most definitely should include air-sealing your attic first! And, for a little more wise investment, air-seal the subfloor above your crawlspace or basement.
Sealing the two horizontal planes in your home’s shell will dramatically improve the benefits of adding attic insulation.
Because here are the top three secrets to a comfortable home with healthy indoor air quality: air infiltration, air infiltration, and air infiltration!
Bird Family Insulation is here to help you achieve your goals for a comfortable and healthy home. Call us today for your free evaluation! (404) 666-8160
