How to Apply Caulk in Cold Weather

You've been meaning to get around to redoing the caulking on your windows all fall, but now the cold weather has arrived and the caulking isn't done. Luckily, cold weather doesn't mean you can't recaulk your windows. There are actually caulks that can be applied in cold weather (all the way down to -20 degrees F). So, using the right caulking and a few simple techniques, you still have time to seal up your windows and save yourself some money on your winter heating bill. Here's how to apply caulk in cold weather.

Things You'll Need

• Silicon caulking
• Hair dryer
• Acetone or methyl ethyl ketone
• Cloths
• Gloves
• Hot water
• Picnic cooler

Instructions

1. Choose the proper type of caulk. You want to be sure to choose a caulk with a rubber or silicon base. Be sure to read the label on the tube or talk to an employee at your home or hardware store. Latex caulk will just freeze before it can set up, so don't use latex caulk.

2. Ensure the substrate is clean and dry before you apply your caulking. A thin layer of ice can form in cold weather and you need to get rid of that before you apply your caulking, otherwise the water will be under the caulk and prevent it from bonding.

3. Use a hair dryer to melt the ice and warm the substrate or clean the area with acetone or methyl ethyl ketone (both available at home stores) and a clean cloth. Cleaning will not only remove the ice, but also ensure the substrate is clean.

4. Store your caulking inside before you want to use it. On the job you can keep it warm enough to flow by putting a jar of hot tap water in a picnic cooler and storing your tubes of caulking inside.

5. Wait for the sun to warm your walls. All wall and window materials will shrink in cold and expand in warm weather. Wait to start caulking until at least mid-morning when the sun has had time to warm the walls and windows. This will allow time for natural movement to take place and make it easier for the caulking to fill the gap.

Tips & Warnings

• Choose a caulk that has a high joint movement capability. Tubes of caulking are usually labeled with one of two sets of plus/minus numbers (either plus/minus 12.5 percent or plus/minus 25 percent). The plus/minus 25 percent has a higher joint movement capability and can withstand more movement without cracking or splitting.

• In terms of material movement, wood is relatively stable, so it doesn't expand or shrink nearly as much as vinyl or metal.

• Silicon caulking won't take paint well, so choose a color that complements your house colors.