Friday, May 19, 2017

Sealing Your Building Envelope


Orlando Insulation Ventilation Home Inspection
The most cost-effective way to cut heating and cooling costs, increase stability, improve comfort levels, and create a healthier interior atmosphere is to reduce the amount of air that flows in and out of your home. Before considering improving insulation or installing a vapor barrier, you should take care of those drafty utility penetrations, windows and doors. Weather stripping and caulking around doors, windows and utility penetrations are two simple and effective techniques for air-sealing that offer quick returns on investment. Weather stripping is used to seal components that move, such as entry and garage doors and operable windows. Weather strips take a lot of abuse and wear out frequently over a home’s lifetime, check them quarterly and replace as needed. Caulking (interior and exterior) is generally used for cracks and openings between stationary house components like; doors, windows, masonry cracks and ledges, utility penetrations any trim or siding joints.

Air Leakage

Air leakage occurs when outside air enters and conditioned air leaves your house uncontrollably through cracks and openings. When it is cold or gusty, an excessive amount of air may enter the house. During summer or warmer weather, conditioned air exits the building envelope, which can result in poor indoor air quality. Air leakage also causes moisture problems that affect the structure’s durability and the occupants’ health. Condensation is a major contributing factor to wood rot in most homes. An added benefit is that sealing cracks and openings decrease drafts, cold spots, and improves comfort. It is important to seal the fire barrier between the home and garage to reduce the chances of carbon monoxide poisoning. Never rely on air leakage for ventilation.

Detecting Air Leaks

The best way to reduce air leakage and controlled ventilation is to have a home energy audit performed on your home. The test, when performed by a licensed professional, will identify air leaks, air quality and if additional ventilation is needed. Before sealing air leaks, assess your ventilation needs for indoor air quality.
If you are planning an extensive renovation of your home, review techniques used for air sealing in new home construction and consider a home energy audit to identify all the ways your home costs you money by wasting energy. To seal air leaks, apply air sealing techniques and materials, including caulk and weather stripping.

How to Seal Air Leaks

Common places air leaks are found:
  • Check the weather stripping on doors and windows.
  • Check caulking on doors and windows. Old, dried and cracked caulking should be removed and replaced. There are many types of caulking for many different applications. You should know what type of caulk you should use before sealing those leaking windows.
  • Check caulking where utility penetrations come thru exterior walls. Check plumbing, ducts, electrical wiring, cable TV and telephone cables comes through the floors, exterior walls, ceilings, and soffits.
  • Install foam gaskets on electrical outlets and switches on perimeter walls.
  • Dirty spots on insulation may be an indication of air leaks and mold. Look for leaks and seal with low-expansion spray foam. Large gaps may require the installation of flashing.
  • Dirty spots on your walls, often around electrical receptacles and switches, or ceilings by vents or light fixtures, may indicate air leaks. Use foam gaskets or spray foam to seal leaks.
  • Single-pane windows allow hot and cold air to transfer. Double-pane low-emissivity windows are more efficient and the cost to upgrade will be recouped in energy saving over a few years.
  • Use foam sealant on larger gaps around windows, baseboards, and other places where air may leak out.
  • Check your kitchen exhaust fan for air leaks. Stop air leaks by upgrading the exhaust fan or cover the vent to stop air leaks when not in use.
  • Check your dryer vent to be sure it is not blocked. Lint will keep the dryer vent door from closing allowing air to leak in and out of your home. This will save energy and may prevent a fire.
  • Check the bottom door sweep and threshold for pliability and damage. Replace damaged seals with energy efficient pliable sealing gaskets.

Fireplace Flues, Dampers and Chimneys

Fireplaces are a major source of air outflow. Keep the fireplace flue damper tightly closed when not in use.
  • Seal air leaks around fireplace chimneys, furnaces, and gas-fired water heater vents with fire-resistant materials such as sheet metal or Sheetrock and furnace cement caulk.
  • Check your makeup air vent damper to ensure it seals properly.
Fireplace flue damper doors are made from metal, constant heating and cooling can cause


the doors to warp, crack or break, creating a passage for air loss.
One way to seal your flue when not in operation is an inflatable chimney balloon. A chimney balloon is made of durable plastic and can be reused many times. It installs easily beneath your fireplace flue and can be removed easily. The balloon will automatically deflate within seconds if it becomes heated, if you forget to remove the balloon before making a fire. Balloons are available in various sizes online and in retail shops.

Sealing air leaks will not eliminate the need for proper insulation or radiant barriers that reduce heat flow through a home’s building envelope.


Frank Carr Home Inspector First Choice Home InspectionsFrank Carr is the Owner / Inspector at First Choice Home Inspections in Deltona, FL serving Volusia, Seminole, Orange and Lake Counties.  Formerly in the building trades, Frank’s focus is a safe home and building FCHI. We believe that consumers have the right to expect the highest standards of thoroughness, fairness and effectiveness from their home inspector and that is exactly what we provide.
First Choice Home Inspections 
(386) 624-3893

Email:  home.inspections@aol.com
Website:  http://1homeinspector.com

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