13 Exterior Caulking Tips You Need to Know

Exterior Caulking Tips You Need to Know

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Caulking is not overly difficult to apply, and it is of course a really convenient thing. You can use it to seal windows, door frames, bathtubs, showers, and so much more. Now, interior caulking is a piece of cake, but where things can get hard is when you want to do exterior caulking.

To help make your life easier, we want to provide you with as many related tips as we can muster, 13 to be exact.

#1: Choose the Right Type of Caulk

First and foremost, if you expect your caulking job to last a long time and actually protect your home, you do need to use the right kind of caulk, specifically the kind designed for exterior use. Just some of the types of caulk you have to choose from include acrylic latex, vinyl latex, siliconized latex, pure silicone, and more.

If you want the best results for exterior use, we recommend choosing pure silicone caulking, as it tends to have the best sealing ability, as well as the best resistance to moisture, sunlight, and temperature. Whatever you choose, make sure that it is designed for exterior use, so it can actually withstand Mother Nature.

Exterior Caulk and Caulking Gun

#2: Try to Avoid Working in Direct Sunlight

Although this may not always be possible, if you can, don’t apply caulking in direct sunlight, or where direct sunlight will hit shortly after applying the caulk. Direct sunlight, when it hits caulk that is not yet dry and cured, can cause it to dry too quickly and to shrink. It can also lead to a much weaker bond, and it may cause your caulking to crack.

It’s not always possible to avoid the sun, but it should be done if at all possible, as it won’t do you any favors.

#3: Apply Caulking in Dry and Warm Weather

Caulking can take quite some time to dry and totally cure, sometimes 24 hours or more. In order for caulking to dry properly, the environment must also be dry. Simply put, there is no chance that the caulk will dry properly in excessive humidity or if it is being rained on.

Moreover, caulking dries best when the temperature is moderate, so don’t apply it in extreme cold or heat. A day with a moderate temperature and low humidity is what you need.

#4: Try to Avoid Working on Windy Days

Windy days are also not ideal for doing exterior caulking. The wind can cause dirt, leaves, and other debris to blow onto the still wet caulking, stick to it, and then dry right into the caulking. Nobody wants an exterior wall or window seams covered in dirt and leaves that are essentially impossible to remove.

A calm day is called for.

#5: Caulk Both Sides of Windows and Doors

A big mistake that many newbies make when sealing doors and windows with caulking is to only apply a single bead to the exterior. For the best weatherproofing, you do really need to apply a bead of caulking to both the interior and exterior seams. It’s the second layer of protection that will pay off big time in the long run.

If there are even small imperfections in one of the caulk beads, at least there will be a second bead present.

Applying Caulking to Windows

#6: Don’t Apply Caulk to Moving Parts

Another mistake that many newbies make when attempting to apply caulking to their doors and windows is to apply it to moving parts.

Folks, we really should not have to say this, as it really is nothing more than common sense, yet for some reason, lots of people make this error. If you want your windows to open and close, and to function properly, you cannot run caulk over any parts that need to retain movement.

#7: Pay Close Attention to Gaps, Cracks, and Other Imperfections

Something that you need to pay extra close attention to when doing exterior caulking is any imperfections in your walls, particularly at seams where walls meet each other in the corners, as well as gaps that may occur between siding.

The whole point of caulking is to create a seal that does not allow moisture in. If you have a bunch of cracks and gaps in your walls, and they aren’t all sealed, the existing caulking that you do have will be rendered totally useless. If water can get in, it needs to be caulked.

#8: Stay Away from Weep Holes and Trimmed-Out Windows

Yet another big mistake that many newbies make is to caulk over the weep holes in windows. These weep holes are designed to let windows breathe, so to speak. They allow moisture to get out. If these weep holes are covered, the window frames may rot.

On that same note, you do also want to stay away from caulking trimmed-out windows. It just won’t end well.

#9: Keep the Tube Tip Tight

The next mistake that many newbies make is to cut off way too much off the tip of the caulking tube.

The wider that hole is, the more caulking will come out at once, and the wider the bead will be. In most cases, you want that tube opening to be small, as this allows for much more precision when applying caulk. It will help prevent you from making a mess.

#10: Use Both Hands

Sure, there are plenty of things that you can do with just one hand, but applying caulking is not one of them. For the best accuracy and stability, you do want to stabilize the caulking gun with your second hand.

It just makes the application process much easier and cleaner.

Caulking in the Exterior

#11: Don’t Run One Long and Continuous Bead

Something you need to avoid doing is running one long and continuous bead of caulk, and this applies to both interior and exterior caulking. If you apply one long bead, by the time you get near the end, you will have pressed the trigger as far as it can go, which then means that you need to reset your trigger hand.

The result of this is a much wider bead right where you had to reset. It’s better to run several smaller beads, while regularly resetting your trigger hand.

#12: Always Ride the Smooth Edge

If there are any bumps present at all, always try to work with them as opposed to moving against them. It’s a lot like moving with or against the grain of the wood when sawing. To create an even and flat caulk bead, pull your gun along with the bumps instead of trying to run a bead against them.

#13. Tape Off the Seams

If you haven’t used a caulking gun before, and you want to avoid making a huge mess, use some basic painter’s tape to tape off the seams being caulked.


There you have it, people, the 13 most important tips you need to follow when doing exterior caulking.

If you follow all of these tips as outlined above and the steps in my general guide to using a caulking gun, you shouldn’t have any problems applying caulking, making it look good, and ensuring that it actually does its job.