How to Caulk Rain Gutters

Co-authored by Ryaan Tuttle

Last Updated: August 9, 2021 References

Caulk is a necessary part of gutter maintenance. The seams of your rain gutters can rust if left unprotected and fungi can begin to grow in the seams if rotted leaves or other organic matter gets caught in the cracks. Professionally installed gutters should have been caulked already, but caulk will need to be replaced every decade or so.

Method 1

Method 1 of 2:

Remove Old Caulk

1
Apply a caulk remover. Caulk removers are special chemical products designed to moisten and soften the caulk, making it easier to remove so that you do not need to chip and chisel it away.^{[1]
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2
Slice the caulk with a blade. Use a clean blade on a utility knife to slice down the center of the softened caulk. Most of the caulk should be freed.^{[2]
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3
Pull away the caulk. You might be able to pull it away by hand, but since gutter caulk can be thick, you may need to grip onto it using needle-nose pliers. Either way, most of the old caulk should come up.
4
Chip away remaining caulk. Use small chisel or the hook end of a painter's five-in-one tool to rake away any leftover chunks until the area is completely clean.^{[3]
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United States Environmental Protection Agency
Independent U.S. government agency responsible for promoting safe environmental practices
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5
Clean the area. Scrub it with a toothbrush or abrasive sponge dipped into a non-ammonia cleaner. Follow by scrubbing the area with a solution made with 1/3 cup (80 ml) bleach and 1 gallon (4 liters) of water. Cleaning the area will remove any fungi or decayed leaves that may have worked their way into the cracking caulk.
6
Let the area dry. Before applying new caulk, the area should be completely dry. Allowing the area to air dry is best, but if rain, other precipitation, or humidity threatens to create a problem, dry it out by hand using a clean, dry towel.^{[4]
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Method 2

Method 2 of 2:

Apply New Caulk

1
Use a silicone caulk. Silicone caulk maintains its integrity in sunlight and extreme temperatures better than latex caulk and it also lasts longer under most circumstances.^{[5]
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Expert Source

Ryaan Tuttle
Home Improvement Specialist
Expert Interview. 30 July 2021.} Moreover, silicone caulk also works better in gaps that expand and contract, which gutters often do in response to changes in temperature. If you have white gutters, use a white caulk. If your gutters are painted in another color, choose a clear caulk.^{[6]
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- If possible, go with a caulk that is specifically formulated for gutters. Gutter caulks are designed to work in the conditions gutters face, and as such, they last much longer than non-gutter caulks.
- Don't use caulk that's labeled for interior use, like your kitchen or bathroom.^{[7]
  X
  Expert Source
  
  Ryaan Tuttle
  Home Improvement Specialist
  Expert Interview. 30 July 2021.}
2
Roughen the surface. Rub the edge of the seam with sandpaper or a wire brush using steady, even pressure. Caulk, especially silicone caulk, adheres better to a surface that is slightly rough and uneven than it does to a perfectly smooth surface. The gutters do not need to be jagged, but it helps if the metal is a little coarse.
3
Cut the tip of the caulk tube at an angle. Do not cut the tip off straight across. Cutting the tip at an angle makes it easier to fit the tube into the seam.^{[8]
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4
Fix the caulk tube into a caulk gun. The tube should be fitted securely at both ends of the gun.
5
Apply the caulk in a straight, small bead across the seam. Start at the front of the seam and gradually pull the trigger of the caulking gun. As you squeeze, a small dot of caulk should emerge from the nozzle. Drag the nozzle down the length of the seam, applying even pressure on the trigger to maintain the same size dot along the entire seam.^{[9]
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- Apply the caulk along the gap between the gutter and facia board. This way, when water runs onto the facia board from the roof, it won't drip behind the gutter.^{[10]
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  Expert Source
  
  Ryaan Tuttle
  Home Improvement Specialist
  Expert Interview. 30 July 2021.}
6
Push the caulk into the joint with a screwdriver. After you have applied the caulk, work it under the joint with the tip of a screwdriver. By working it into the joint, you ensure a stronger seal.
7
Apply another line of caulk. Draw a second line of caulk above the first using the same method and amount of pressure as you used to create the first. Do not push this line under the joint.^{[11]
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8
Smooth the caulk with your finger. Use your finger to smooth the beaded line into a smooth strip of caulk. The width should be even throughout the entire line.
9
Allow the caulk to dry. After it has dried, check your work to verify that the caulk is secured.^{[12]
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Official site for the U.S. Department of Energy, which provides resources related to energy safety, conservation, and efficiency
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Expert Q&A

Question

What is the best caulk for gutters?

Ryaan Tuttle
Home Improvement Specialist
Ryaan Tuttle is a Home Improvement Specialist and the CEO of Best Handyman, Inc. in Boston, Massachusetts. With over 17 years of experience, he specializes in building home service businesses, focusing on creating scalable and efficient brands. With the help of his global team, the companies have achieved over 10+ million in sales and received recognition through magazine features, and enjoy partnerships with wikiHow and Jobber field service software. Boston Magazine and LocalBest.com have named Best Handyman Boston the Best Handyman in Boston. Ryaan holds Construction Supervisor and Home Improvement Contractor Licenses.

Ryaan Tuttle

Home Improvement Specialist

Expert Answer

Exterior-rated, 100% silicone caulk is definitely the best caulk for your gutters. Try not to use kitchen or bathroom caulk outside, since it's not designed for outdoor use.
Question

Why should I caulk between gutter and fascia?

Ryaan Tuttle
Home Improvement Specialist
Ryaan Tuttle is a Home Improvement Specialist and the CEO of Best Handyman, Inc. in Boston, Massachusetts. With over 17 years of experience, he specializes in building home service businesses, focusing on creating scalable and efficient brands. With the help of his global team, the companies have achieved over 10+ million in sales and received recognition through magazine features, and enjoy partnerships with wikiHow and Jobber field service software. Boston Magazine and LocalBest.com have named Best Handyman Boston the Best Handyman in Boston. Ryaan holds Construction Supervisor and Home Improvement Contractor Licenses.

Ryaan Tuttle

Home Improvement Specialist

Expert Answer

When water runs onto the fascia from the roof, a line of caulk prevents it from going behind the gutter.
Question

Does temperature affect caulking?

Donagan

Top Answerer

Modern outdoor caulking is theoretically unaffected by temperature. Well-known brands are pretty reliable.