Air leaks in your home can be costly. So it's important that you seal all openings in and outside of your home for energy efficiency. Below are some guidelines to follow when caulking your home.

A house needs to be caulked:

• Between window drip caps (tops of windows) and siding
• Between door drip caps and siding
• At joints between window frames and siding
• At joints between door frames and siding.
• Between window sills and siding
• At corners formed by siding
• At sills where wood structure meets the foundation
• Around outside water faucets or other special breaks in the outside house surface
• Around pipes and wires that penetrate the ceiling below an unheated attic
• Between porches and main body of the house
• Where chimney or masonry meets siding
• Where storm windows meet the window frames, except for drain holes at the window sills
• Where the wall meets the eaves at the gable ends, if you have a heated attic.

Tools needed for installation

• Ladder
• Caulking gun
• Caulking compound cartridges
• Oakum, caulking cotton, glass fiber strips or sponge
• Putty knife or large screwdriver

Safety
You will need to use a ladder to reach some of the areas that need to be caulked. Be sure to use it safely.

• Level and block the ladder in place. Have a helper hold it if possible.
• Don't try to reach that extra little bit to the right or left—get down and move the ladder.
• Carry your caulking gun with a sling, so you can use both hands climbing the ladder.

Materials
Caulking compound is available in these basic types:

• Oil or resin based caulk - readily available and will bond to most surfaces—wood, masonry and metal; not very durable but lowest in cost for this type of application
• Latex, butyl or polyvinyl based caulk - readily available and will bond to most surfaces, more durable, but more expensive than oil or resin based caulk
• Elastomeric caulks - most durable and most expensive; includes silicones, ploysulfides and polyurethanes; the instructions provided on the labels should be followed
• Filler - includes oakum, caulking cotton, sponge rubber, and glass fiber types; used to fill extra wide cracks or as a backup for elastomeric caulks.

Q: How much caulking compound is necessary?
A: Estimating the number of cartridges of caulking compound required is difficult since the number of cartridges needed will vary greatly depending upon the size of cracks to be filled. Rough estimates are:

• 1/2 cartridge per window or door
• 4 cartridges for the foundation sill
• 2 cartridges for a two story chimney

It's best to start the job with a half-dozen cartridges then purchase more as you need them.

Caulking and filler installation

1. Before applying caulking compound, clean areas of paint build-up, dirt or deteriorated caulk with solvent and a putty knife or a large screwdriver.
2. Draw a good bead of caulk and make sure the bead overlaps both sides for a tight seal. This will take a little practice. First attempts may be a bit messy.
   Note: A wide bead may be necessary to make sure caulk adheres to both sides.
3. Fill extra wide cracks (like those at the sills where the house meets the foundation) with oakum, glass fiber insulation strips, etc.
4. Finish the job with caulk in places where you cannot quite fill the gaps.
   Note: Caulking compound also comes in rope form, so you can fill extra long cracks easily this way. Unwind it and force it into cracks with your fingers.