Stopping Air Leakage in Your Home

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Once you have identified the air leakage points from an assessment of your home, you can proceed with the insulation process.   


You should begin by sealing up small cracks, leakages and penetrations on the inside of the outside walls, floors and ceilings. The interior is usually warmer and applied sealant lasts longer as it is not exposed to harsh weather conditions.

Caulking is handled with an inexpensive caulk gun and a tube of suitable material . You can choose from a myriad of caulking materials available on the market: the staff at building supply stores can make recommendations on the best caulking material for your project. Do not give in to the temptation to buy cheaper, low-quality caulking materials. These are usually difficult to apply and are not very durable. Wood-stove chimney areas or hot water heater flue vents require high-temperature silicone or polysulfide compounds. 

  • Determine which areas require caulking and the most suitable material for each area.
  • Do not caulk when it is cold but when the weather is close to room temperature.
  • First clean out the area that is to be caulked. Holes and cracks bigger than 1/4" must be filled with oakum or foam rope.
  • The caulking compound nozzle should be cut big enough to cover the crack. Use the wire from a coat hanger or a long nail to break the nozzle’s thin metal seal.
  • The caulking gun should be aimed at right angles to the crack. This will push out enough caulking compound to cover both sides of the crack. Since caulking compound shrinks, it is better to use more than required.
  • Your finished caulking result, or "bead", will look smooth and clean if done correctly. You can smooth the bead’s surface with a moist finger (but don’t lick your finger afterwards).
  • There may be compounds that require certain chemicals such as paint thinner to clean up. Read the label before using the compound to determine cleaning methods before you begin.


Electrical Boxes

As air leakage around switches is very common, it is easy to get an off-the-shelf solution to fix the problem. Special pads and fireproof foam gaskets can be placed on the inside of the decorative plate. If you want ensure that you have a lasting seal, apply some indoor latex caulking compound onto the gasket face before putting on the decorative cover. If you are renovating the room as well, put plastic "hats" all around the electrical boxes. These plastic hats are designed with an opening to accommodate supply wires and small flaps to seal the vapor barrier. It is important to make sure that the entrance portion of the supply wire to the hat is sufficiently sealed with some acoustic sealant.


How to stop air leakage around a window frameWooden frames in older homes are normally fitted with single glass panes, but air leakage occurs when the putty has dried out. You should remove the old putty and replace it with a good glazing compound that will offer durability and high flexibility. Do not use old-fashioned putty. Another area that is prone to air leakage is the area between the