The Best Exterior & Interior Caulk

An Exterior & Indoor Caulk & Sealant Breakdown

Caulk is a wet substance that dries as a flexible material that seals cracks and gaps. It is the most effective material at preventing air and moisture from entering surfaces. General usage includes expansion joints, small gaps, and cracks. Caulk should not be used to fill screws or nail holes.

Our long-term experience and field tests enable us to provide sound recommendations for the best interior and exterior caulk for multiple applications.

The Importance of Choosing the Right Caulk

Caulk provides unparalleled visual improvements when painting interior or exterior surfaces, making cracks between materials that overlap more appealing to the eye. Sealing gaps from one material to another provides a seamless transition between surfaces and materials such as interior walls, baseboards, or exterior siding and trim.

Caulk expands its versatility, offering specific formulations for metal, tile, glass, and various surfaces. However, the common usage is sealing doors and windows.

If you notice gaps and cracks around your home, it’s time to get some caulk and seal those up. Choosing the best caulking is determined by the surface, area, and climate you are applying it in.

Spending a few extra dollars to protect your home from mold and other potential damage is worth the investment. Making doors, windows, and exterior siding airtight will save you money on your energy bill!

Caulking products come in various types and are ideal for different settings. We’ll walk you through the characteristics of the top 10 sealants to help you determine the best caulk based on usage.

The Top 10 Exterior & Interior Caulks & Sealants

Dap Extreme Flex

Dap offers a wide range of caulk, and Extreme Flex is one of the better offerings for general-purpose use.

  • Paintable: Yes
  • Type: Acrylic Urethane
  • Dry Time: 2 Hours Paint Ready, Touch 30 mins
  • Pros: Low Cost, Easy to Find, DYI Friendly Quick-Dry
  • Cons: Loss of Flexibility Over Time, Low Moisture Resistance

GE Silicon Supreme Hybrid

Ge Silicone Supreme is the most durable paintable exterior caulking we have used.

  • Paintable: Yes
  • Type: Silicone
  • Dry Time: Paint & Rain Ready in 30 mins
  • Pros: Paintable Silicone, Strong Seal, Shrink & Crack Resistance
  • Cons: Hard to Tool & Spread, Hard to Apply Over Rough Surfaces, Messy


Lexel is the best solution for hard-to-stick indoor surfaces subject to water or high moisture.

  • Paintable: Yes
  • Type: Silicone
  • Dry Time: Dry Time 1 Day, Cure Time 1 Week
  • Pros: 400% Joint Movement, Stick to Glass, Withstands Extreme Temperatures, High-Quality
  • Cons: Interior Use Only, Not Sold Everywhere, High Price, Limited Colors

Sherwin-Williams Maxflex

This indoor/ outdoor caulking is best for exterior surface, offing thick coverage and outstanding adhesion to multiple surfaces.

  • Paintable: Yes
  • Type: Acrylic Urethane
  • Dry Time: 4 hrs Paintable, Cure Time 12-24 hours
  • Pros: Thick Formulation, Best Overall Exterior Performance
  • Cons: Unused Tubes Have a Short Shelf Life, Hard to Wipe

Sherwin-Williams Sher-Max

SW Sher-Max is the best for indoor painting projects, creating a clean and seamless interphase between walls & trim, making cutting in easier.

  • Paintable: Yes
  • Type: Urethanized Elastomeric
  • Dry Time: 12 hours Paintable, Cure Time (24-48) hours
  • Pros: Wipes Clean, Easy to Use, Limited Shrinkage, Increased Elasticity
  • Cons: Thin Consistency, Longer Cure Time

GE Silicone

This caulk will not react to metal and meets ASTM C-920 Class 25 flexibility test requirements.

  • Paintable: No
  • Type: 100% Silicone
  • Dry Time: 30 min Moisture Resistance, (24-48) hr Drytime
  • Pros: Mold, Crack, Moisture Resistance, Available in Multiple Colors, Fill Large Cracks, Does Not Shrink
  • Cons: Non-Paintable, Hard to Use/ Clean, Heavy Odor

Lucus Sealants

Sealing aluminum and other metal gutters with Lucas will ensure a leakproof seal for the lifetime of the gutter system.

  • Paintable: No
  • Type: Thermoplastic Elastomer
  • Dry Time: Moisture Resistance (1-4) hrs
  • Pros: High Bonding & Sealing, Various Color Options
  • Cons: Professional Usage Recommended

Sakrete Sealant

Sakrete polymer non-sag sealant fills expansion joints and mortar crack up to “1 wide and withstands high car and foot traffic abrasions.

  • Paintable: Not Recommended
  • Type: Polyurethane
  • Dry Time: 1-4 hrs Set Time, 72 hrs Cure Time
  • Pros: UV & Temperature Resistance, 250 lbs Tensile Strenght
  • Cons: Oxidation Over Time, Color Often Does Not Match the Surface

OSI Quad Max

OSI provides professional solutions for siding, window, and door installations and has some of the best construction adhesives.

  • Paintable: Yes
  • Type: Silane Modified Polymer
  • Dry Time: Paintable in One Hour, Cures in 24 hrs
  • Pros: Multipurpose Sealant, Matching HardiePlank Siding Colors, Complete Home Sealant Solutions
  • Cons: Hard to Find, Limited Flexibility


Depending on your roof type, Henry is a well-known leader who provides several roofing sealants and cement and is trusted by roofers nationwide.

  • Paintable: No
  • Type: Butyl, Asphalt & Options
  • Dry Time: 1 hr for Sealants, 24-48 hrs for Butyl
  • Pros: Several Sealant Solutions, Ability to Apply Over Wet Surfaces, Warranty
  • Cons: Mess Application, Stains Hands & Surfaces

Latex Painters Caulk Usage & Durability

Water-based latex caulking is prominent among painting contractors. The main reason is that it’s easier to manage and clean up. Latex caulking enables the most straightforward applications for painters to easily paint over it, making every crack and seal appear even more uniform.

Expect premium versions to last between 4 – 8 years! Latex caulking is adequate for filling in expansion joints outside wood siding and small gaps in window and door frames.

It’s important to understand that the caulking has no actual rubber. Instead, acrylic polymers are the main ingredients. It can be confusing, but latex merely alludes to the pliability of the caulking – misleading, we know! Premium versions of this caulking will contain fewer clay fillers and more good stuff!

Tip: Be cautious if you live in a cold environment. This type of caulk does not stick well in temperatures below 40 degrees Fahrenheit. Because it is water-based, dry weather conditions are also ideal.

Premium Acrylic Latex Caulk Usage & Durability

Acrylic caulk is another versatile, water-based caulk. It is easy to apply and clean. Acrylic-based caulking can be used to fill cracks and gaps narrower than 1/4 inch on wood, HardiePlank, Drywall, and PVC trim surfaces.

Acrylic latex caulk offers similar durability to latex. However, this caulking is more resistant and fortified with better quality acrylic polymers lasting 10 to 15 years. Aside from being easy to paint over, this caulking also comes in various colors, enabling it to match a variety of interior and exterior surfaces.

Like its latex brother, acrylic caulk works best when the outside temperature is above 40 degrees.

Exterior Silicone Caulk Usage & Durability

Silicone caulk is very flexible and is great at adhering to tile, glass, metal, and other smooth materials. Typically, you will find silicone caulk applied to roofs. The product can also be applied to Masonite and vinyl siding, making it a versatile caulk for outdoor use.

Because it is not water-based, it is extremely effective at preventing mildew and mold. However, some outdoor silicone cannot be painted over. Refer to our list above for paintable silicone sealants.

Silicone sealant is not the easiest material to apply, but it is the best exterior caulk in terms of durability, lasting up to 50 years!

Silicone caulking is not water-soluble and requires mineral spirits for cleanup. Silicone sealants can be applied at various temperatures, and there are non-toxic options available.

Exterior Urethanized Caulking Durability

Urethanized caulking is an extremely durable, all-purpose filler and is among the most versatile and longest-lasting. Because urethane-based caulkings increase adhesion properties, they stick to virtually any surface. These sealants are paintable but don’t require paint for moisture resistance or added protection.

There are various formulations of urethane-based caulkings, but none last as long as their silicone counterparts. However, urethane caulking expands after application and works wonderfully to insulate and prevent air from entering.

If you want a durable caulk that mitigates toxins and is easy to work with, urethane-based caulking is the sweet spot for premium exterior caulk. Premium versions last as long as 25 years.

Exterior Butyl Rubber Exterior Caulk Usage

Butyl rubber sealant is a popular pick due to its elasticity. The additional flex is great at sealing exterior joints that expand and contract. Butyl rubber can be applied to masonry, metal, and gutters and is the most resilient waterproofing sealer best for chimney flashing and roofing applications.

Butyl rubber is known to shrink more than other sealants. Therefore, two applications are recommended. You shouldn’t apply it to cracks or holes larger than 0.25 in.

The strength of butyl is its flexibility. However, it is prone to becoming brittle and losing its elasticity, resulting in oxidation and hairline cracks. In areas of extreme weather exposure, expect this caulk to last between 8 and 12 years.

Exterior Modified Silicone Polymers

Chemically modified caulking and sealants combine acrylic, silicone, and urethane and can be painted over with latex/ acrylic paints.

Modified versions of exterior caulking are some of the best exterior caulks for wood, aluminum, vinyl, and fiber cement siding. It is also great at sealing gaps around doors, vents, and windows.

This type of caulk is known for its flexibility, and modified silicone polymers can be applied in wet conditions.

Polyurethane Exterior Caulking

Polyurethane is the most versatile and durable caulking to date. It is formulated for heavy commercial usage and can stick to virtually any surface.

Polyurethane caulking has a high odor, and while some labels may recommend interior usage, we would have to disagree as home improvement specialists. Make no mistake, this is premium caulk, and some may argue it’s one of the best, but it has its place.

Don’t Cheap-Out

No matter the situation, make sure to choose the best exterior or indoor caulking or sealant for your home or commercial project. All of the products listed are excellent performers that we use and rely on daily. The cost of each product is relatively inexpensive and worth the minor cost upgrade compared to other inferior offerings.

Because of the flood of crap caulking, there are a lot of misleading reviews and product claims. All of our recommendations are from real-world usage, and we have been a home service provider for over 20 years.

Contact us if you need painting or home installation services and you live in Raleigh, Cary, Durham, or the Triangle areas.

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