The Building Envelope: Energy-Saving Components

As building science improves, the attention paid to the building envelope, the parts of the structure that separates the outside from the inside, is becoming more and more detailed. But what parts make up the building envelope, and what functions do they serve in that capacity? In this post, we'll take a solid look at what a solid building envelope entails.

Bottom Floor and Foundation Wall System

How many times have you heard about problems with leaking basements or drafty sill plates? Sealing your foundation wall system is just as important as having good drainage away from your walls.

  • Sheet Foam. If you have concerns about heaving from ice heaves, insulating your foundation floor with sheet foam can help reduce this problem. It's a common tactic used in northern climates where it's too hard to get to the frost line.
  • Membrane. Worried about damp soil or water infiltration? Modern waterproofing membranes provide long-term, durable protection for your basement.
  • Sealant. For those problem areas where your utilities come through or you have small drafts, caulk or weatherstripping can go a long way to help keep the cold winter air out.
  • Spray Foam. For larger gaps or to provide better insulation, spray foam is an excellent option. It helps seal as well as providing a heat barrier.

Above-Grade Wall System

As an example of poor wall design and retrofit, a small farmhouse dating to the late 1800's had wooden clapboard siding on the outside and stucco on wooden lathing strips on the inside. During one particular renovation, the stucco was removed by being struck until the cement cracked, and it was then removed from the interior of the house and replaced with wood paneling. At the same time, insulation was added by drilling through the upper part of each wall cavity and blowing in cellulose. Unfortunately, the stucco keys from the backside of the lathing fell down to the bottom of the wall cavity, allowing wind to blow through in the winter, creating a terrible draft. Hence the importance of good wall design.

  • Insulation in a AtticInsulation. Whether you're considering blowing cellulose in a retrofit, installing fiberglass batting to a new construction or adding sheet foam to the exterior, insulation is your first line of thermal defense in your walls and roof.
  • Studs. If you get extreme winds or cold, you may want to consider doing an offset design with your studs to prevent thermal transference.
  • Structure Wrap. Whether you're adding house wrap or a more specialized commercial structure wrap, this layer helps prevent air from entering the building envelope anywhere except where you want it to.
  • Tape. Don't forget the joints! To get the best performance, make sure you seal the joints in insulation, sheet foam or house wrap with tape, otherwise these areas become prime areas of air infiltration.

Through-Wall System

Any point air can pass through the structure's walls is a potential point of failure for your building envelope. There are three basic points where a building component passes through the envelope entirely.

  • Windows. There are a variety of new technologies at play in windows, from insulated, multi-pane windows that help create insulative space between panes to special coatings that reflect heat back into a structure.
  • Doors. Exterior doors in our part of the country should always have insulation to help prevent thermal bridging. A properly-fitted storm door that helps keep wind off your exterior door will help keep your home warmer.
  • Weatherstripping and Caulk. Your doors and windows are only as good as the sealant used to keep the wind out around them. A 1/8" gap around a door is the same as a 6" hole in the middle.
  • Utility Inlet or Outlet. Don't forget to seal around these key areas. For exhaust systems, make sure to put baffles in that will restrict airflow when they're not in use.

Roofing Seal System

If your roof won't keep the water out, what's the point? Having your roof well-sealed helps prevent moisture from building up inside, causing significant damage and potential health issues.

    • Sealant. This keeps water from getting behind flashing or around pipes or vents that protrude through the roof.
    • Extra Protection in Problem Areas. If you have valleys, dormers or other areas where water tends to leak, make sure they're sealed up right.
    • Roofing Material. You can have the best roof in the world, but it won't protect your home if it's not wind resistant. Make sure your roof design will hold up to harsh weather.

Where does your building envelope need improving? At Wallboard Supply Company, we have what you need to make your home more comfortable than ever. Contact us for more information.

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Wallboard Supply Company is a third generation, family run business that has been serving New England's building needs since 1970. Bob Filion started the company with a commitment to provide quality drywall and finishing products with unmatched customer service. The company has grown over the years, expanding its' product range, but never wavering from its' core values.