If you use electric heating, caulking will allow you to reduce your home's energy consumption and lower your electricity bill.
In addition to effectively reducing air leaks, it prevents moisture from penetrating the insulation or the building envelope.
Key concepts to remember...
- Purchase a high-quality caulking compound suitable for the task—cheap materials are often difficult to apply and less durable.
- Follow the instructions on the cartridge and take note of the recommended cleaning product (water or specific solvent).
- While caulking your doors and windows, take the opportunity to install or replace weatherstripping and seals as needed to minimize air leaks.
- Remember that a building needs a certain amount of fresh air—if you suspect your home has ventilation issues, speak with a heating system specialist.
- Preferably caulk during dry weather and avoid doing so when the temperature is below 5°C (41°F), as the compound will harden and become difficult to apply.
- Plan for an adequate number of cartridges—a standard cartridge produces a bead 6 mm (1/4 in) wide by 7.6 m (25 ft) long.
1. Identify the area to be caulked
- Visually inspect the most common sources of air leaks (e.g., electrical outlets, baseboards, windows, fireplaces, chimneys, access hatches).
- Look for signs of poor sealing (tears, water traces, etc.)—if necessary, take a photo of suspicious areas.
- Slowly move a candle or a thin sheet of paper around windows and at the joints of walls, floors, and ceilings. If the flame or paper moves, there is likely an air leak.
- The presence of spider webs is also a good indicator of air leaks, as spiders tend to weave their webs where air circulates to catch food.
2. Clean the area to be caulked
- Ensure the area is free of dust, paint chips, and old caulking residue.
- If necessary, remove cracked and dried-out compound using a utility knife and clean the area thoroughly with a brush.
- Replace damaged wood and re-nail boards where applicable.
- For very wide cracks (over 6 mm or 1/4 in), insert a filler material such as oakum or a foam backer rod.
3. Prepare the caulking cartridge
- Cut the tip of the cartridge at an angle using a utility knife.
- Break the inner protective seal by inserting a wire or a long nail into the cartridge.
4. Apply the caulking compound
- Hold the gun at a right angle and follow the crack or joint, applying steady, light pressure on the trigger.
- If necessary, use a small disposable stick to push the compound into the crack to fill it completely.
- Ensure the compound covers both sides of the crack; add more if needed using the gun.
- Once finished, do not release the trigger abruptly to avoid making a mess.
5. Smooth the joint
If you are using a water-based or silicone-based compound, dip your fingers in a bowl of soapy water and run them over the bead to smooth the joint; the soap will prevent the compound from sticking to your fingers.
Source: Hydro-Québec