A Guide to Window Caulking
Whether it’s hiding unsightly cracks, keeping the winter chill at bay, or sealing around the tub, caulking plays a crucial and often overlooked role in your house. We use it to bridge gaps where different building materials meet, and it performs the vital function of keeping outside air and water away. Proper window caulking can save you money on energy bills and prevent rot and mold from forming on your walls and windows.
Also, caulking can make your paint jobs last longer and your house look magnificent. Because of advanced technology, today’s caulk is very durable. However, it won’t last forever. So when it falls apart, repair the joints as quickly as possible to prevent extensive damage to your home.
Considerations for Caulking
When selecting caulk for a particular job, you need to consider:
- Location: When caulking outdoors, choose caulk that’s flexible enough to withstand joint movement, and that can hold up to the elements.
- Moisture: In areas that remain wet such as around a sink or tub, use a caulk that’s highly resistant to both mildew and water.
- Material: Some caulks stick better to certain materials than others.
- Application: Some caulks are easy to apply and you can clean them up with water while others are chaotic and need solvents to clean up. Some caulks have a strong smell while curing and some even release toxic gases.
- Watch the weather: Weather affects:
- The size of the joint at the time of caulking—joints swell in higher temperatures
- The ability of the caulk to perfectly cure and develop its unique physical properties—caulk can’t cure well in hot temperatures, or freezing temperatures
- The ability of the caulk to adhere to the surfaces flawlessly
- The contaminants on the joint surface (such as dust, dew, pollen,)
Whenever possible, caulk in ideal weather. That is, at temperatures between 40°F and 90°F. This also applies to the temperature of the surface; it should be between this range as well.
If it just snowed or rained and you’re using water-based products, allow these surfaces to dry completely before applying the caulk. Wet surfaces make it nearly impossible for proper adhesion and will prevent the caulk from curing properly. So avoid applying caulk if you expect snow or rain within 24 hours. If you have to caulk, cover it with a tarp to prevent dampness from getting onto the caulk and making it wash out.
Types of Caulk
A lot of caulking compounds are available on the market today, and it’s vital to select the right one for the job.
Silicone: This is among the most durable caulking substances available. It is water-resistant and therefore has a wide number of uses. However, the characteristics of silicon encourage metal corrosion and it does not adhere very well to wood.
Siliconized latex: Don’t confuse this with silicone caulking. Siliconized latex has better adhesion than silicone. It is water-resistant, meaning, it can be used in bathrooms and can also be painted over.
Polyurethane: These are by far the highest quality outdoor sealants. They are so universal because they can seal surfaces of different materials such as glass and wood, or metal and wood. Polyurethane are easy to work with, but they are vulnerable to the ultraviolet light present in sunlight so it’s recommended to paint over them. They are also more expensive than the other caulking compounds so consider the number of windows you need to caulk before starting.
Acrylic latex: This caulking is inert to temperature changes and does not expand or flex. One of its major disadvantages is that acrylic latex doesn’t last long in moist environments. Although you can paint over it, it isn’t recommended for sealing window frames.
Prepare the Surface
Good surface and joint preparation is the most crucial prerequisite for a long-lasting and professional job. This separates the pros from the amateurs.
Remove Old Caulk
Use a putty knife or a painter’s 5-in-1 tool to remove all the old caulk in the joint. You can use a heat gun to loosen paint and soften the old caulk to make removal easier. A caulk remover can also work well to remove all types of old caulk.
Clean the Surface
Ensure the surface is free from peeling paint, rust, mold, mildew, oil, grease, wood fibers, old caulk, soap scum, etc. A wire wheel that is mounted on a drill is usually the best solution for cleaning dirty concrete, and a wire brush is perfect for removing contaminants. To remove grease or oil, use a grease-cutting cleaner.
After cleaning, thoroughly rinse and vacuum everything out. Remember, chemicals are good for cleaning, but they also prevent proper adhesion. Thoroughly rinse off any chemical cleaners from the surface.
Primers Are a Good Idea
Although they’re not required, they’ll help, particularly in joints that are subjected to regular pressure and stress such as a home in extreme weather. A primer also promotes better adhesion for a longer-lasting seal. Any normal primer will work fine.
Buy a Caulk Gun
Caulk is not like toothpaste. You can’t dispense it easily by just squeezing. Instead, you need a caulk gun to seal your windows properly. Window professionals recommend buying a quick-release caulk gun; one that releases pressure when you release the trigger. It will save you much hustle compared to the cheaper guns that continue to release caulk even when you don’t need it.
Apply the Caulk Properly
You first have to load the caulk into the caulk gun. Chop off the tip of the caulk at a 45-degree angle. This is the angle at which you will release the caulk. A majority of caulk guns have a pin to help you further puncture the hole. Pull the trigger back and place the caulk in the chamber starting with the back end first. Push the trigger forward to hold the caulk firmly in place.
Do some practice caulking on a piece of cardboard or newspaper to get a feel of how the work is done and to help avoid weird bumps after pulling the trigger over and over. Now you are ready to go.
For best results, start your first caulk line from an inconspicuous area just in case your practice wasn’t good enough. Hold the nozzle parallel to the joint and apply a 3-foot bead. Don’t apply more than this because you also must smooth it out before it dries. By the time you get to the more noticeable areas, your skill will have produced better results. And if you mess up, just scrape out the bead immediately, wipe the surface and start over.
Tool the Bead
Tooling is gliding over the caulk bead to make it smooth, neat and establish good adhesion. It’s not mandatory; however, if you want your caulking to last long so you won’t have to redo it, you need to do it. You can do it with your finger or with several tools such as a beading tool, trowel, or the back of a spoon.
During tooling, avoid scraping off too much of the caulk because you might withhold the joint of sufficient caulk to stretch and seal well. Use plain water when tooling water-based caulking and use mineral spirits or soapy water for solvent-based caulks.
Clean Up the Mess Immediately
It’s difficult to remove dried caulk, so keep rugs handy for the cleanup task. If you use masking or blue painter’s tape along the sides of the joint, ensure you remove the tape immediately after you finish tooling so it can come off cleanly, leaving a smooth, even line.
Caulking your windows is one of the most straightforward and easier ways to enhance energy efficiency in your home. As much as it will shield you from losing lots of money, it is also an easy DIY project to take on. However, if you meet unforeseen complications, consult a window expert near you.