The Best Caulk for Baseboards in 2021

Caulking baseboards fills unsightly gaps, keeps out insects, and adds a smart, professional finish to a room. This guide takes an in-depth look at the best products for the job.

By Bob Beacham | Updated Oct 26, 2021 1:03 PM

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Best Caulk For Baseboards

Photo: amazon.com

Many DIYers are familiar with running caulk around their bathroom fixtures, and a number of products are designed specifically for that purpose. Caulk also can be used with baseboards. An effective gap filler, caulk creates a super-neat, professional finish, and it helps prevent insects from getting into the wall or liquid spills from seeping underneath it.

Several different types of caulk—but not all—are suitable for baseboards, which can make selecting the right product a challenge. This guide offers an in-depth look at key features to consider, useful tips for successful application, and our recommendations for the best caulk for baseboards throughout your home.

  1. BEST OVERALL: Gorilla 8060002 100% Silicone Sealant, 10 oz, White
  2. BEST BANG FOR THE BUCK: DAP INC 18152/11440 White Alex Plus Acrylic Latex
  3. BEST MOLD/MILDEW RESISTANT: GE Sealants & Adhesives Paint Projects Max Shield
  4. BEST GAP FILLING: Sashco 10016 Big Stretch Caulk 10.5-Ounce
  5. MOST VERSATILE: Red Devil 0705 230 Lifetime Ultra Premium Elastomeric

What to Consider When Choosing the Best Caulk for Baseboards

No such thing as a “general purpose” caulk exists. While the best exterior caulk also might be suitable for use on interior baseboards, it’s important to understand its properties. The following section explains the key features of different types of caulk, so you can confidently choose the correct product for each location.

Types of Caulk

Many types of caulk are on the market, but not all are suitable for baseboards. Masonry caulk, for example, has a polyurethane base and often contains sand to add texture. Refractory caulk is heat resistant and frequently used around fireplaces. Butyl rubber caulk is highly flexible and works well to seal guttering. However, none of these combine the ease of application and smooth finish required for caulking baseboards.

The best caulks for baseboards fall into three categories: latex (also called polymer acrylic or acrylic latex), pure silicon, and latex with silicone, which seeks to combine the best of both worlds. Though caulk is fairly inexpensive, generally speaking, silicone costs a bit more.

Many caulks are also referred to as “elastomeric.” This is not a type, but rather an indication of the caulk’s elasticity. Caulking must remain flexible so it doesn’t get brittle or crack when dry. Pure silicone is naturally elastomeric, and although latex may be, it’s not always.

Quality and Durability

Caulking baseboards is not the type of job that must be redone regularly. Although a chance always occurs that accidental damage could require a repair, if a quality product is applied correctly, regular maintenance shouldn’t be necessary.

Cheap types of caulk from unknown brands are frequently available in discount stores. Since its quality cannot be trusted, it’s best to avoid it. Caulk from a reputable manufacturer should last a minimum of 25 years. While 40 years or more is not uncommon, some—often the pure silicone products—come with a lifetime guarantee. Whether it actually lasts that long depends on how well it’s applied, the type of baseboard material, and any movement of the walls. However, this type of guarantee demonstrates the manufacturer’s confidence in its product.

Pro Tip: If using white caulk on baseboards that won’t be painted, always check whether it’s resistant to yellowing. This is particularly important for pure silicone caulks, which cannot be painted.

Curing Time and Paintability

The length of time that caulk takes to dry varies considerably among the different types. Latex dries fastest; some can cure in as little as 30 minutes. Fast drying time can be particularly useful if a few substantial gaps require a second application or if the baseboard and caulk will be painted. If the area needs to be used as quickly as possible, latex caulk is the optimal choice.

Pure silicone generally takes longer to cure. While sometimes these caulks are described as water resistant after curing for a relatively short time, a full cure frequently takes 24 hours. Appearances can be deceptive, as caulk can seem dry to the touch fairly quickly because a skin forms on the outside. Pure silicone caulk typically takes longer to dry all the way through.

Latex caulk is often called “painters caulk,” which refers to the ease with which it can be colored. Pure silicone is not paintable. Any silicon-based product that is paintable is a combination of silicone and latex.

Gap Size and Adhesion

New walls should be straight and flat, so caulking the baseboard is the final finishing touch. In many older residences, the walls are almost never completely straight or flat, and even the floors may be slightly uneven. So always consider the gap-filling properties of a particular caulk and whether an area needs one or two applications. This is when the caulk’s elastomeric ability becomes important. Some caulks can fill gaps of up to 2 inches wide but still remain durable.

Baseboards can be made of natural wood, wood composite, PVC, or other man-made substances, so also check how well a particular caulk adheres to the chosen material. Pure silicone and latex silicone products usually offer the most versatility.

Mold and Mildew Resistance

If the baseboards are in potentially damp or humid environments, such as bathrooms, kitchens, conservatories, and so on, ensure that the caulk is also waterproof. If it isn’t, the changing humidity conditions can cause the caulk to break down quickly. Pure silicone is 100 percent waterproof, and many latex-silicone hybrids are as well. Latex products vary, so more care is needed when checking their properties.

Mold and mildew resistance is also important when choosing a baseboard caulk for a humid environment. Although pure silicone is likely to give the greatest protection, don’t take it for granted.

Tips on How to Caulk Baseboards

The following tips for how to caulk trim and baseboards outline good general guidance. The type of caulk chosen may also impact application, so always follow the instructions on the tube. These instructions may differ slightly from what’s provided here.

  • Invest in a good caulking gun. A smooth trigger action provides better control over the flow of caulk, making the job quicker as well as neater and ensuring less cleanup.
  • Vacuum or sweep the area to ensure it’s clean and dry. It especially should be free of dust or grit, which can prevent the caulk from adhering properly.
  • Although not essential, most experts usually recommend taping the wall or floor to prevent the caulk from going beyond where it’s intended. Use a low-tack painter’s tape rather than masking tape.
  • Cut the nozzle at 45 degrees, leaving an opening the appropriate size for the bead of chalk. Cut small at first and enlarge if necessary.
  • Run a test bead on a piece of paper or card to get the feel of how the product flows.
  • Apply a smooth, continuous bead, controlling the speed to create a consistent thickness.
  • Stopping and starting can produce lumps of excess caulk, so clear any obstacles before starting to provide as much space to work as possible.
  • After the caulk has been applied, it must be smoothed, and while tools exist specifically for this purpose, using a wet finger is usually best. Keep a small bowl of warm water and a cloth handy to wipe any excess caulk off your fingers. As with the original caulking, try to maintain steady speed and pressure.
  • Once satisfied with the finish, remove the painter’s tape slowly. It’s best to do this before the caulk dries to minimize the risk of lifting the caulk.
Best Caulk For Baseboard

Photo: amazon.com

Our Top Picks

Now that we’ve discussed the key features of caulks suitable for baseboards, it’s time to look at some of the products currently available. The following recommendations provide an in-depth reference for the best caulk for baseboards in their respective categories.

Best Overall

Best Caulk For Baseboards Option: Gorilla 8060002 100% Silicone Sealant, 10 oz, White
Photo: amazon.com

This high-quality, 100 percent silicone sealant from Gorilla works well for a wide variety of jobs, and its combination of ease of use, flexibility, and durability make it the optimal choice for caulking baseboards. It requires minimal pressure of the caulking gun to apply and glides smoothly across the baseboard’s surface. Its initial cure is relatively rapid, and a skin forms in around 30 minutes. While the manufacturer claims it’s waterproof at this stage, it’s still quite soft and takes 24 hours to cure fully.

Gorilla silicone sealant remains flexible during its entire life, so it won’t crack or split during the normal movement that buildings generally experience. The silicone surface is resistant to mold and mildew, and it keeps its clean, white finish (but remember that 100 percent silicone cannot be painted). While the product has poor adhesion on brick, masonry, and cement, these surfaces typically don’t have baseboards.

Product Specs

  • Type: 100 percent silicone
  • Curing time: 24 hours
  • Durability: Lifetime

Pros

  • Good flexibility
  • 100 percent waterproof
  • Does not yellow with age

Cons

  • Not paintable
  • Not for brick or masonry

Best Bang For The Buck

Best Caulk For Baseboards Option: DAP INC 18152_11440 White Alex Plus Acrylic Latex
Photo: amazon.com

DAP brand’s Alex Plus acrylic latex includes silicone for superior flexibility and waterproofing. It has excellent adhesion and, unlike 100 percent silicone, it’s suitable for highly porous surfaces like masonry or brick in addition to the usual wood or PVC. DAP’s Alex Plus is also mold and mildew resistant.

Its gap-filling capability of ⅜ inch is more than enough for most applications (other products are advised to fill bigger holes). The water-based formula has low odor for workability. It starts to dry quickly, providing a surface that can be painted in as little as 30 minutes. It can take acrylic or oil-based paints, though the latter will require around 24 hours to dry fully. Rapid drying is usually a benefit, but quick action is necessary in the event of a mistake. Alex Plus can be wiped off with a damp cloth within 2 or 3 minutes after application; after that, it must be scraped away.

Product Specs

  • Type: Acrylic latex with silicone
  • Curing time: Paintable in 30 minutes; 24 hours for full cure
  • Durability: 40 years

Pros

  • Very good multisurface adhesion
  • Good flexibility
  • Paintable

Cons

  • Maximum ⅜-inch gap
  • Rapid drying time that’s less forgiving than other products

Best Mold/Mildew Resistant

Best Caulk For Baseboards Option: GE Sealants & Adhesives Paint Projects Max Shield
Photo: amazon.com

GE Sealants’ Paint Projects Max Shield acrylic latex uses what the manufacturer calls an “advanced polymer formula.” This gives it some impressive benefits, but it’s not all good news. On the plus side, GE’s baseboard caulk flows smoothly for easy application. In fact, it behaves much like a silicone although it contains none. For example, unlike some latex caulks, it’s 100 percent waterproof once cured. With excellent flexibility, it’s an effective gap filler. It dries quickly and can accept water- or oil-based paint in approximately 30 minutes. It’s particularly notable for its 7-year resistance to mold and mildew. While many caulks claim these properties, no other manufacturer guarantees how long the protection lasts.

But GE’s Paint Projects Max Shield caulk has an unusually unpleasant odor, which can irritate the skin, eyes, and respiratory system. The work area should be well ventilated, and wearing eye protection as well as a mask and gloves is recommended.

Product Specs

  • Type: Acrylic latex
  • Curing time: 30 minutes
  • Durability: 60 years

Pros

  • 7-year mold and mildew resistance
  • Paintable
  • Affordable

Cons

  • Irritant to skin, eyes, and respiratory system
  • Unpleasant odor

Best Gap Filling

Best Caulk For Baseboards Option: Sashco 10016 Big Stretch Caulk 10.5-Ounce
Photo: amazon.com

Most new homes are built with great precision, and while every house moves or settles over time, almost any baseboard caulk is suitable for new construction. Older homes, or those in areas in which ground movement is frequent, present a different challenge. Thanks to its excellent gap-filling ability, Sashco’s Big Stretch acrylic latex caulk becomes invaluable in these situations. Plus, once dry, its flexibility is exceptional: It can stretch to 500 percent of its original size without splitting or cracking.

Big Stretch is easy to apply, comes in a choice of 13 different colors, and is paintable. It also adheres well to almost any surface, including porous material that can cause problems. Unfortunately, it’s not waterproof and has minimal resistance to mold or mildew, so it should not be used in kitchens or bathrooms. In fact, any humidity impacts its drying time, which can be anywhere from 4 to 48 hours.

Product Specs

  • Type: Acrylic latex
  • Curing time: 4 to 48 hours
  • Durability: Lifetime

Pros

  • Tremendous elasticity with no slump
  • Water-based, low-odor formula
  • Paintable

Cons

  • Negligible anti-mold or mildew properties
  • Not for kitchens or bathrooms

Best Versatile

Best Caulk For Baseboard Option: Red Devil 0705 230 Lifetime Ultra Premium Elastomeric
Photo: amazon.com

Red Devil’s acrylic comes closer than most products to an all-purpose caulk, and it’s a good choice for baseboards. The low-odor formula is water based and thus environmentally friendly. It flows freely, so it’s easy to apply. It adheres well to almost any material and can be used both indoors and out, though the drying period requires special attention for exteriors. It has good gap-filling capabilities, and it won’t split or crack under normal conditions. Red Devil Lifetime is also mold and mildew resistant.

While it’s 100 percent waterproof once fully cured, the manufacturer warns that curing can take 3 days, and the caulk should not be exposed directly to water during that time frame. Red Devil’s elastomeric acrylic is available in six paintable colors; just wait 3 days before painting, or drying time will be delayed further.

Product Specs

  • Type: Acrylic latex
  • Curing time: 72 hours
  • Durability: Lifetime

Pros

  • Remarkably versatile
  • Waterproof, all-weather protection
  • Paintable

Cons

  • Relatively slow drying

Our Verdict

Gorilla 100% Silicone Sealant is a high-quality solution that will prove effective for most baseboard caulking tasks. Quick and easy to use, it has excellent durability. However, it isn’t paintable and is available only in white or clear. DAP Alex Plus Acrylic Latex combines the elasticity of silicone with the paintability of acrylic, making it good value for the money.

How We Chose the Best Caulk for Baseboards

As a DIYer who has undertaken major renovations of two homes, I have ample hands-on experience using caulk products for baseboards. I used the following criteria when choosing these top picks:

  • Quality: Lots of different caulks are available, and it’s common to find budget products at local hardware and home improvement stores. However, although the prices may be attractive, there’s no way to assess their long-term performance. For that reason, we selected caulk only from brands with a well-established reputation. Durability is another key issue, and each of our choices offers a long-lasting solution.
  • Flexibility: Flexibility is important in terms of both ease of application and suitability for a variety of baseboard materials. Each of the products chosen also offers good gap-filling properties.
  • Value: Although none of the products selected are particularly expensive, we nevertheless chose baseboard caulks from across the price spectrum.

The Advantages of Caulking Baseboards 

It’s not difficult to learn how to caulk baseboards, but the process does take time and patience. Most DIYers who make the effort reap big benefits.

  • Caulked baseboards typically don’t show any unsightly gaps. They supply a professional finishing touch to a room.
  • Caulk prevents insects from invading the gap between the baseboard and wall or floor. Once insects establish themselves, it can be very difficult and expensive to banish them. Removal typically involves toxic chemicals.
  • Caulk prevents dirt buildup between the baseboard and wall. It also keeps water from creeping in underneath the baseboard, which helps stop mold, mildew, and, eventually, rot from taking hold.

FAQs

The information supplied here should have provided a thorough understanding of how various different types of caulks work and how to apply them effectively. We’ve also highlighted some of the best caulks for baseboards currently available. In researching the topic, a few questions cropped up regularly, so we’ve provided answers below.

Q. Can I make a better product by mixing two kinds of caulk?

No. Each type of caulk is specifically formulated for the properties described, and each has been factory mixed for optimum performance. Attempting to mix products will not only be messy and make them difficult to apply, but it will also likely reduce effectiveness, not improve it.

Q. How do I caulk baseboards to a tile floor?

The process of caulking tile is the same as for other floors, which is described above in “Tips on How to Caulk Baseboards.” If the tile is in an area that frequently gets damp or wet, a waterproof silicone or acrylic-and-silicone caulk with mold and mildew resistance should be used.

Q. Should I caulk the bottom of baseboards?

Yes, it’s a quick and efficient way to conceal unsightly gaps, and it prevents insects from infiltrating under baseboards and into the wall.