Caulking is filling gaps, cracks, or joints with a sealant that adheres to surfaces and prevents the penetration of air, water, sound, light, smoke, insects, or drafts. It is usually done in areas where two surfaces meet, such as windowsills, door frames, and baseboards.
Caulking is essential in windows because they are the most vulnerable areas in your home that can lead to air leakage. By caulking your windows, you can create an airtight seal that will prevent heat loss in winter and cool air from escaping in summer. This will help you save on energy.
Are you in search of relevant guidance in this regard, right? Then, read this article to seal your windows in the best possible way. This article will enlighten you about the dos and don’ts of caulking windows, which you shouldn’t ignore. So, let’s begin.
Dos of Caulking Windows
- Do remove the old caulk first.
- Before caulking your windows, removing the old caulk first is important. Doing so will help you to prevent any moisture or water from entering the area to cause any damage. To remove the old caulk, follow these simple tips:
- Use a putty knife or any other sharp tool to remove the old caulk.
- Afterward, clean the area with rubbing alcohol.
- If you find any difficulty during this process, contact a caulking contractor. The caulking contractors provide professional services to remove the old caulk before applying the new sealant.
- Do clean the area before applying the new caulk.
When the old caulk is removed, do not forget to clean the area appropriately. Make sure that the area is free of any dirt or debris material. Moreover, it is important to dry the area completely before applying the new caulk. Remember that if any grease is left in the area;
It will prevent the new caulk from sticking properly. Therefore, ensure the area is clean and free of any harmful material that might ruin the new caulk. A few tips to consider in this regard are listed below:
- Use a rag and wipe the area with rubbing alcohol.
- You can also use a disinfecting spray to clean the area of any harmful substances.
- Rinse the area with water and use a hair dryer to dry the area.
Don’ts of Caulking Windows
Do not caulk over the old caulk at any cost.
Never caulk over the old caulk because the old caulk will pull away from the new caulk. And you will see a thick or messy caulk line from the window that will disrupt the window look. So, why not be careful and not caulk over the old caulk? A few tips in this regard must be considered. For instance:
- Scrape off the old caulk with the help of a putty knife made of steel.
- Slice through the caulk with a knife and peel it away.
- For multiple caulk layers, use needle-nosed pliers to do the best work.
- You can also use caulk-removing specialized tools to remove the old caulk adequately.
How To Caulk Windows (Methods)
Choose The Right Caulk

A crucial step in caulking windows is to choose the right caulk. The caulk usually comes in 4 basic types. These are:
- Silicone caulk
- Polyurethane
- Acrylic latex caulk
- Siliconized latex
Choose the given types as per your requirement. If you are looking for the best interior application caulk, go for acrylic latex caulk. The acrylic latex caulk is good for complementing the existing color schemes and has few chemicals. If you require the best caulk for exterior windows, then siliconized caulk is recommended.
This caulk has durable bonds and great resistance to weather. Polyurethane caulks are not water-based but are solvent-based. This property makes them powerful caulks for structural applications or areas with larger gaps. For tubes and sinks, silicone caulk is the best. It is highly resilient against mildew and temperature, making it suitable for bathtubs, kitchens, and HVAC applications.
Use a Caulking Gun Having a Thumb Release
Avoid cheap caulking guns because these guns will release excess caulk on the windows. Instead, use a caulking gun that has a thumb release button. With this thumb release, you can release pressure on the caulk when you are done running a bead.
Hold Gun Properly

There is no doubt that the caulking gun matters but more than that, holding the gun properly also matters. Pick an angle and consistently hold the gun to that angle so you can caulk your windows appropriately. A few tips in this regard are listed below:
- Start from one end. Then, hold the trigger down.
- Make a continuous and straight line from one end to the other.
- Do not hesitate to talk to an expert before doing this activity. Remember that the right caulking will benefit your home for about five years. So, pay considerable heed to the said points.
Use Both Hands for Running a Bead

Both hands must be used to control the caulking gun properly. It is recommended to use your dominant hand to hold the gun. Afterward, pull the trigger and support the gun barrel with your other hand.
Another thing to remember is that you must keep your wrists straight and move your body and elbows specifically while running the bead. If you bend your wrists, it will alter the gun’s angle, eventually altering the bead’s appearance. A few more tips in this regard are listed below:
- Do ride a smooth edge when you caulk a seam.
- While you run the bead, keep the tip from riding the textured siding. Doing so will help you to have a better-looking bead, and the caulk will seal the seam.
- If you can’t run a smooth bead, tape off your seams. This tip is good to consider, especially if your hands are shaky or you cannot move the gun smoothly.
Choose The Right Sealant

A wrong sealant will not give appropriate protection to your windows. Therefore, always choose the right sealant to provide long-lasting protection. Always consider choosing high-quality and appropriate caulk material. Follow the following tips in this regard:
- Choose an exterior caulk for exterior windows. The chosen caulk should resist weather or temperature to prevent leakage or moisture.
- For interior windows, choose an interior caulk. Your chosen caulk should be non-toxic and holds paint well.
- If the windows for which the caulk is needed are located in a humid area, choose an interior caulk that is mold-resistant and water-proof.
Don’t forget to Select The Right Applicator
The right applicator is necessary for caulking the windows in a befitting manner. Do not forget to select the right applicator, i.e., the caulking gun. Always choose a good quality caulking gun. Please do not use inexpensive caulking guns because they will look messy over your windows. A few tips must be considered in this regard:
- Look for a caulking gun that has a comfortable grip.
- Choose a gun that has a smooth plunger rod.
- Hold the gun at a 45-degree angle to seal the cracks.
- Always hold the gun consistently to get your desired results.
Don’t Apply Too Much of The Caulk
Though it may be tempting to apply more quantities of the caulk, especially over bigger gaps; however, this can lead to serious issues.
If you apply too much caulk, then the caulk will spread to the adjoining areas. Instead, never over-apply the sealant and focus on the following tips:
- If the crack you are sealing is more than 1cm deep or 1cm wide, do not apply any further sealant.
- Fill the space with a backing foam before caulking to get better results.
- Remember that applying more caulk is not always better. It will lead to unattractive windows.
Don’t Apply Caulking To Inappropriate Areas

Remember that you do not need to apply caulking to problematic areas of the window. These areas include:
- A part of the window that moves. Otherwise, you won’t be able to open the windows.
- The areas above the window frame.
- The areas above the weep hole should be avoided to the maximum.
- The components mentioned above will stop moisture from getting trapped. Moreover, they will lead to water damage; therefore, they shouldn’t be blocked.
Don’t Run a Continuous Bead Horizontally or Vertically
It is recommended not to run a continuous bead from right to left or from top to bottom. When you reach the end of the bead, you need to change your grip on the caulking gun. This will lead to a change in the uniformity of the bead. Rather, do the following steps:
- Caulk from one end to the middle of the seam and then stop for a while.
- Then, start at the other end to meet the first bead.
- Doing these steps will help you maintain a steady position, eventually turning into a uniform bead.
- Also, do not cut the end of the caulk tube tip too far down. Otherwise, there will be no way to make the bead thinner.
Don’t Apply Caulk On Poorly Trimmed-out Windows
The caulk generally works on relatively narrow seams. Ideally, they should be around ¼ inch tighter or wider. If the caulk is applied to larger gaps, it can create an unattractive mess, and it will sag out of the gap.
So, why not get rid of this issue and not apply the caulk on poorly trimmed-out windows? It would help if you also considered the following tips in this regard:
- If you have gaps more than ¼ inch wider
- C.R. Laurence Closed Cell Backer Rod is a good product to consider for this activity.
- When you fill with a foam backer rod; then, run your bead off the caulk.
Shape the sealant After Applying

Another great tip for caulking your windows is to shape the sealant once you apply it. After you place your sealant, ensure that you have given an appropriate shape to it for a neat and professional appearance. For this, you need to do the following activity:
- Run your finger across the sealant to ensure that it fills the opening. You can also do this with a wooden stick if you do not want to use your finger.
- Following these tips and tricks will help you caulk your windows efficiently. Moreover, they will ensure you caulk the windows neatly and cleanly without messing.
FAQs
Do you caulk windows inside or outside?
Yes, it is best practice to caulk the window from the interior and exterior while installing new windows. This will block unwanted air leaks and, using a caulk gun, will make sure to fill up the gaps to have a clean line.
Is it good to caulk windows?
Caulking a window is important to keep your home energy efficient and comfortable.
What parts of windows should you caulk?
The window areas that should be caulked are the trim around the top and sides where your window meets.
Bottom Line
When mold or mildew indicates water leakage or the caulk of your home is at least five years older, it’s high time to caulk your windows. If you do not caulk your windows, it will severely damage your home’s energy efficiency.
However, properly caulking your windows is also important to ensure no leakages occur in your home. To attain the best results, do not forget to heed the points above.
Happy window caulking.