Did You Know?
Poor caulking is one of the most common exterior complaints among new home owners. Water penetration can turn your dream home into a nightmare. For the builder, it can be a recurring one, because water not only damges the house cosmetically, but can do serious structural damage.
The Proper Caulking Bead
I like to cut the nozzle squarely with a cross section producing the appropriate bead size. I hold the gun at about 45º to the work surface and PUSH the caulking ahead, forcing it into the joint. The joint bead should has a flat to slightly concave surface, and when I use quality caulking I have better, longer-lasting results. Finger-tool the bead with a moistened finger only if you absolutely have to, but NEVER wet your finger in the mouth or on the tongue, as you may ingest hazardous materials. Read product labels carefully - some caulkings are hazardous, even through skin contact.
Package instructions recommend cutting the nozzle at about 45º and PULLING the caulking gun. Either way is fine, as long as you ensure the caulking is pressing into the joint to be filled. Avoid pulling the caulk into a "spagetti string" because then you stick your fingers into it, and make a mess!
Cleanliness is job #1.
Clean the surfaces to be caulked with dilute acetone or a solvent. Even the oils on your fingers can cause caulking, especially silicone caulking, to not adhere properly.
Air infiltration through the outside walls of the homecauses a great deal of heat loss. This can be corrected by the addition of caulking. The caulking should be applied wherever two different materials or parts of the house meet.
There are certain tools that you will need to caulk your home. You will need a ladder, a caulking gun, caulking cartridges or compound, backer rod or some other materials for stuffing large openings, and a putty knife or large flat-head screwdriver.
There are several types of caulking some of which will last longer than others. Most caulks are composed of latex or silicone. Many companies now make caulks that are combinations of latex and silicone. They are often marketed as "siliconized latex" or "latex plus silicone." These products offer the ease of use of latex with the added durability of silicone.
Caulk comes in two forms: a cartridge or a squeeze tube. A cartridge and caulk gun give a more continuous bead than a squeeze tube, which is better for small projects. Cartridges typically have 9-11 ounces of caulk versus a squeeze tube, which has 3-6 ounces.
Quality caulking products have much greater resilience and durability, and although they are more expensive to purchase, their life expectancy is far greater and worth the investment. Caulking is very time consuming. Therefore if you use the most durable products, it will be years before you have to caulk again.
See Lowe's caulk buying guide
Before applying the caulking compound, clean the area of paint buildup, dirt, or deteriorated caulk with solvent and a putty knife or large screwdriver. Look around the edges of a window or door. There should be filler in all of these cracks. If it is old, brittle, or broken, or if it's missing altogether, you should reseal it with a new application of caulking.
Drawing a good bead of caulk will take a little practice. Your first attempts may be a bit messy. Make sure the bead overlaps both sides for a tight seal. A wide bead may be necessary to make sure that the caulking adheres to both sides.
Caulking compound also comes in rope form. Unwind it and force it into cracks with your fingers. You can fill extra wide cracks this way. Caulk around pipes and other holes that show from the outside. Fill extra wide cracks like those at the sills (where the house meets the foundation) with backer rod. In places where you can't quite fill the gaps, finish the job with caulking.
Caulk This Way - Fine Homebuilding
Click on illustrations to zoom
Gil Strachan is a professional home inspector, representing Electrospec Home Inspection Services in east-central Ontario since 1994.