How to Winterize Basement and Attic Areas

Wooden stairs in an unfinished basement.
  • 2-8 hours
  • Beginner
  • 25-75
What You'll Need
Weatherproof caulk
Foam insulation
Pipe insulation
Plastic window film
Aluminum tape

Cold, ice and winter weather have a way of creeping into basement and attic areas of the home first. They find the chinks, the cracks, the weak areas, and draw valuable heat away from the house. Protect the vulnerable parts of the home, and the entire house will feel warmer. Winterizing basement and attic areas will reduce energy costs and protect against damaging, potentially costly, weather problems.

Step 1 - Look for Leaks

Start in the attic and check thoroughly for leaks. Wait for a rainy or very breezy day to search for wet spots and drips or piercing drafts in the attic ceiling. Use weatherproof caulk to block any leaks if and when they’re discovered. Use your hands to feel for drafts around windows, doors and along the walls. Put caulk in all these gaps, but not just on the inside of the home. Caulk the gaps inside and out for more effective winterizing.

Step 2 - Insulate

Climb into the attic and look down. If the ceiling joists in the attic are visible, you need more insulation up there. Experts advise at least 12 inches of insulation in attic areas; ceiling joists are no bigger than 11 inches. Foam is easy to work with and affordable, but fiberfill is also a popular insulating choice. In the basement, cover any exposed pipe with foam insulation. Simply wrap the foam around the pipes and keep it in place with duct tape. Plastic PEX pipes do not need insulation, but metal pipes can freeze and burst in cold weather.

Step 3 - Reverse the Fan

If you have an attic fan, turn it to the reverse position so it will be drawing warm air upward, instead of sending cool air down. Remember to flip it back the other way once the weather grows warmer!

Step 4 - Cover the Windows

Basement and attic windows generally do not have curtains to block the cold air. Cover them with plastic film instead. Plastic film window kits are very affordable, and because basement windows are small the kits go a long way.

Step 5 - Cover the Attic Stairs

The hole in the ceiling where the attic stairs live could be pulling warm air from your rooms up into the attic, where it isn’t doing anybody any good. The stairs can be covered with a wooden box, which may be purchased at home improvement stores. Build your own out of plywood to save money. In a pinch, cover the hole with a tarp or plastic instead.

Step 6 - Seal Ducts

Basements and attics often have exposed duct work. Wipe all of it down to clear off the dust and cover all grooves and joints with aluminum tape. Despite it's name, this is not what duct tape was actually made to do. Don't use it here!

Step 7 - Replace the Filter

Take out the old filter in the furnace and replace it with a fresh one. When the furnace operates more efficiently, it heats the entire home more effectively.

Winterize the basement and attic areas thoroughly to save on heating costs and keep the whole house warmer throughout the cold season.

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