Is your home among the 8 million US homes that have Hardie siding installed? Hardie siding is, without a doubt, an attractive building material.
And guess what? Care and maintenance are the secret to durability. For instance, the gaps ought to be sealed to prevent water, dust, bugs, and other things from getting in. By sealing them, you protect the siding from damage and keep it looking great.
And do you know what you need for that? The best caulk for Hardie siding, definitely.
But when choosing caulk, you ought to be very careful. The right caulk is that which is easy to smooth and bring to a nice, even, and professional finish. Moreover, the caulk must be able to shut out the water, insects, cold air, and all other unwanted elements.
So, are you looking for quality, long-lasting caulk for siding as well as other areas around your home? The guide below is for you. I’ll introduce to you the market’s top products.
Let’s jump in.
Flex Shot Rubber Adhesive Sealant Caulk
5 Out of 5
GE Sealants & Adhesives Advanced Silicone
5 Out of 5
Gorilla Heavy Duty Ultimate Construction Adhesive
5 Out of 5
GE Window & Door Max Shield
4.5 Out of 5
Sashco Big Stretch High Performance Caulking
4.5 Out of 5
james hardie caulk
4 Out of 5
Top Rated 11 Best Caulk for Hardie Siding Reviews
1. Flex Shot Rubber Adhesive Sealant Caulk
Are you wondering how you’re going to stop water from getting in through the cracks in your siding?
The first product in this review may be just what you need. The Flex Shot Rubber Adhesive Sealant Caulk is manufactured by Swift Response, an American firm that specializes in adhesive products. In the sector, Swift Response is a trusted brand that offers excellent quality.
Well, what makes the Flex Shot the ideal product for someone seeking the best caulk for Hardie siding? Let’s see.
The most obvious reason is the effectiveness of the adhesiveness of the caulk. This substance is super strong, joining items firmly.
Perhaps you’ve ever applied Hardie siding caulk that came off sooner than expected. Or that got knocked right off when the rains came.
Guess what? With the Flex Shot, you’ll not experience this issue. The product stays in the cracks for decades.
Caulking the gaps in siding is not easy. Some of the gaps are hard to reach, and often, you have to use a caulking gun.
But you may be thinking, “I don’t have a gun.”
Not a problem! The tube is designed for use with or without a gun. It has an extended tip that reaches the concealed parts very efficiently.
If you’re looking for quality outdoor caulk that you can use for multiple tasks, this is the one. It is a versatile product that works not only for Hardie and cedar siding but also for concrete, wood, cement, ceramics, and so on.
Feel free to use it to fix gaps and cracks on sinks, tiles, windows, pipes, and whatnot.
Ordinarily, when you cut the tube of any caulk, you have to use the entire tube. Otherwise, the caulk will dry and become unusable. But that doesn't apply to the Flex Shot Sealant Caulk. This unit comes with a unique cap that goes over the tube, keeping the caulk fresh and soft for months after the tube is cut. How cool is that!
2. DAP Acrylic Latex Caulk
DAP is, without a doubt, one of the most familiar brands among DIYers in the US. For anyone looking for the most refined sealants, insulating foams, adhesives, or other quick repair solutions, DAP is where to look.
When it comes to caulking for cement board, the DAP Acrylic Latex Caulk is worth considering.
This is an almost perfect formula that works no matter the conditions. Whether you live in a place that receives a lot of rain or plenty of sunshine, the caulk will seal your siding effectively.
The formula is made of acrylic latex combined with silicone. Therefore, it is super sticky. It’s the kind of sealant that will not come off once it is cured.
If you’ve been struggling to keep the water out, this is a substance you can count on. It has excellent water resisting properties.
Moreover, its chemical composition fights bugs, mildew and mold reliably.
Want to keep your siding looking its best for years? The provided water resistance and the protection from mildew and other biological infestations will come in handy.
Have you been facing trouble trying to tolerate the smell of caulks and sealants? No more of that with the DAP Acrylic Latex Caulk. This product’s odor is really faint and easy to withstand.
What’s more, you don’t need to take extra caution when using the caulk. Why? Because it contains low levels of toxicity.
3. GE Sealants & Adhesives Advanced Silicone
Waterproof, practical, and multipurpose are some of the major factors people look for when shopping for the best caulk for Hardiplank siding. Now, concerning these factors, the GE Sealants & Adhesives Advanced Silicone is one product that will not let you down.
Hardie siding is a beautiful yet inexpensive building material. However, exposure to outdoor elements like rain can take a toll on it. For instance, when it rains, the water getting in through the cracks might cause the siding to start rotting from the inside.
Want to prevent that and keep your siding secure for ages?
Then you got to seal the gaps with a product that has excellent waterproofing capacity.
That product is, undoubtedly the GE caulk. Its performance in keeping the water at bay is quite impressive.
Mold is another element that can cause the deterioration of your siding’s quality. However, with this product, you needn't worry about it for the next ten years. The substance has properties to fight mold and mildew unfailingly.
Through time, the gaps in your siding will undergo various changes. Depending on the weather, they may enlarge or shrink. If the caulk you’re using is not able to conform to these structural changes, you may notice cracking or splitting of the caulk.
Luckily for you, here is a caulk that is flexible enough to move with the changes. The GE product expands and contracts to ensure there are constant sealing and protection without cracking or separation.
So, you want a product that you can utilize on a range of surfaces? You will love this unit’s versatility. You can use it on fiber cement, ceramics, wood, plastic, and more.
When you apply this reliable product, you’ll not need to worry about those gaps for the next 40 years.
4. Gorilla Heavy Duty Ultimate Construction Adhesive
For over 20 years now, Gorilla has been a top adhesives and sealants brand in the US. It is practically a household name among a good number of DIYers.
One thing about the Gorilla Heavy Duty Ultimate Construction Adhesive is that it is marketed as an instant-grab product. Is it? Absolutely!
A common reason why lots of people for this caulk is that it holds almost immediately. If you’re an already experienced user and you don’t need to keep tweaking the bead, then speed matters.
The Gorilla caulk is there to support you need to caulk quickly. In the event that the rains are imminent, this benefit will come in helpful. The caulk will not get washed off. Moreover, it will prevent the water from gaining entry.
Apart from being a pretty good caulk for cedar siding, this product works on a wide variety of surfaces. Thanks to its incredible strength, the caulk can be used to join ceramics, concrete, drywall, plaster, metal, even other wood items.
From the kitchen to the garage and patio, the areas where this substance can be used are limitless.
Maybe you're thinking of painting over the gaps after painting them. That's a fantastic idea, but you have to know, not all caulking accepts paints. Thankfully, the Gorilla caulk is paintable.
Also, the caulk comes in various colors to increase your chances of getting a matching shade. The main options include white, clear, and tan.
5. GE Window & Door Max Shield
Are you getting ready for winter? Apart from sealing the siding, you got to take care of the gaps around the doors and windows. That way, you'll be sure that moisture will have a few entry points as possible.
You may be wondering, what is the ideal caulking for doors and windows? One product you definitely want to try is the GE Window & Door Max Shield. I am going to show you why.
Firstly, this is a 100 percent waterproof and weatherproof formula. The product seals the gaps very efficiently, keeping the water from getting into the house. It has tremendous adhesiveness, so it holds the gaps firmly and resists washing off. It’ll stand up to wind, water, and snow.
Did you know gaps stretch or contract with time? Yes, depending on the temperature and other properties like wind, the gaps around your windows and doors have slight size changes.
In case you apply rigid caulk, it can easily crack or separate depending on these movements. That is why flexibility matters. It would help if you got caulking that moves with the changes.
You won’t believe how flexible the GE max shield is. This product can conform to size changes of the gap up to +/- 35%. Hence, it is unlikely that you'll see cracks or separations on the caulk.
Mildew and mold giving you a headache? This is just the solution you need. It is formulated to kill these organisms and prevent water-damage on your doors and windows.
Yes, the Max Shield is ideal for doors and windows, but this is a pretty versatile product. If you need caulking caulk or caulking for cedar siding or Hardie boards, this product will undoubtedly come in handy.
6. Red Devil Lifetime Ultra 230 Caulk
Have you been experiencing the problem where you apply caulk, but then after a while, the caulk starts to crack or shrink? I understand what a pain that can be.
When cracking or shrinking happens, the protection from moisture is cut short. Water gets in and damages your surface. Moreover, aesthetic appeal goes away. The caulked surface no longer looks so good.
What you need to do to avoid caulking that cracks or shrinks is to be very particular about what to buy. My advice is that you get a highly elastomeric product like the Red Devil Lifetime Ultra 230 Caulk.
This product stretches so effectively that it covers gaps that as wide as an inch. If the gap's size increases or reduces, the caulk's elastomeric nature allows it to conform accordingly. That way, there are no cracks and or shrinking.
Having to keep resealing gaps with caulk is not very convenient. And yet, it is what many DIYers have to go through from year to year to keep their homes protected.
Speaking of that, do you know what makes this Red Devil caulk superior? Its unbelievable longevity. Forget the products that offer a guarantee of 30 years. This one offers a lifetime guarantee. You won’t need to do caulking ever again. Once you apply this caulk and paint it for extra protection, the gaps are sealed for life.
Yes, you can paint on the product without any issues.
If you’re seeking a versatile product, you’ll find this one quite suitable. You could use it on brick, metals, concrete, painted and unpainted wood, and more. It's a product you can put on your bathtub, sink, countertop, siding, trim, and so on.
7. White Lightning 3006 All Purpose Adhesive Caulk
Ease of use is definitely a major deciding factor for anyone looking for the best caulk for fiber cement siding. To have a good experience, you want the product to go on smoothly and evenly with the right consistency. It needs to be easy to spread and level with a tool or your fingers.
Are these the aspects you’re seeking? Then you may want to check out the White Lightning 3006. This product comes in a cartridge with an extended nozzle.
Even if you don't have a gun, reaching those hidden areas will be a piece of cake, thanks to the extended tip.
Applying the product is pretty straightforward. The caulk lays down smoothly in a nice bead that levels itself without a hitch. To smooth it, you don't have to use a tool. Your finger will do an excellent job.
Speaking of finger-smoothing, you may ask – does the product damage the skin? Not at all. This is a relatively safe caulk that will not even cause skin irritation to most people.
If you make mistakes, you might want to know how easy it will be to remove the caulk. Thankfully, this is a product that you can easily wash off with water before it dries. The same benefit makes it a breeze to remove the product from your hands in case you touch it.
What about the color? Will it match the surface? Well, this model is brown. However, there are three other choices – white, gray, and transparent. Aside from that, you can paint the seal once it dries, since this is paintable caulk.
8. Sashco Big Stretch High Performance Caulking
The truth about doors, siding, windows, and other parts of your house is that they move. Weather elements such as rain, heat, wind, and so on cause these movements. In turn, the size of the gaps around the doors, siding, and other structures changes.
When these movements happen, most caulks cannot take it. You start to notice cracks and tearing. But if you’re using a high-performance caulk like the Sashco Big Stretch, gap changes are not a concern.
First off, this is a concrete adhesive. Weather elements are definitely not going to loosen its grip.
Secondly, the product is highly elastic. That means it is able to adjust itself according to the size of the gap. It will twist, compress, or stretch based on the gap movements.
Because of the superior properties of this caulk, it is a reliable solution to weather. You can rest assured that the water will not get any space to flow into the house.
Imagine dealing with a caulk that is smelly or that irritates your skin if you touch it. Now imagine using a product like the Sashco Big Stretch, which is low-odor, and which doesn’t affect your skin. That now is user-friendliness.
Handing this product is a piece of cake. It spreads as quickly as mayo, and you can use your fingers.
Big Stretch comes in a cartridge that you can use with a gun or with your bare hands. It's a versatile formula that you can use around vents windows, crown molding, siding, doors, and more.
9. Red Devil 0848 Premium Caulk with EZ Squeeze Tube
Red Devil is a popular name among DIYers. If you ask anyone who likes doing their repairs around the home, they probably have heard of the Red Devil sealants. The thing with this brand is that it offers excellent quality. Notably, its products are designed with ease of use in mind.
Before I proceed, I have to mention that this product is not meant for use with a caulking gun. Instead, it is a caulk that you operate only with your hands.
When using caulk, ease of use is an important aspect. No one wants a product that gives them a headache. Good caulk for cedar siding is that which flows smoothly and consistently.
If there’s one thing I can bet on, it is the effortless operation of the Red Devil. If you look at the tail end of the tube, there’s a rolling feature attached. This innovative feature is placed there to help you get the caulk to the nozzle with minimal effort. You just roll it up, and the caulk comes out of the tip smoothly and evenly.
The beautiful thing about it is that there are no clogs. As such, covering those gaps is a cinch.
How reliable is the caulk? One of the reasons why people tend to prefer this unit over its competitors is the superior effectiveness it packs. Whether you’re using it interiorly or exteriorly, the product provides a secure hold.
It also offers a reasonable degree of flexibility, so it moves with the gap without cracking or separating. For long-lasting repair, this water-based formula is a great pick.
If you want a multipurpose sealant that you can use on windows, trim, doors, ceramic tiles, Hardie siding, and other structures, get the Red Devil 0848 Premium Caulk.
10. OSI Quad Max Caulk
Just installed James Hardie siding? While the material is definitely beautiful, you have to take specific steps to make it last. Crucially, you got to seal the gaps between the sidings. That way, you prevent the water from getting in and thus, you prevent moisture damage.
So, what reliable Hardie siding caulk is there, you ask? The OSI Quad Max Caulk you may want to have a look at, and I’m going to show you why.
James Hardie siding comes in a range of colors. When choosing caulk, you could go for matching colors, so you don't have to paint the caulk afterward.
The beautiful thing about OSI is that it has a matching color for all the Hardie siding colors available. From steel gray and Neptune blue to designer cream and navy blue, you can get any color you like.
A good caulk is one that sticks. Recognizing that fact, Osi presents a product with strong adhesiveness. To apply it, you don’t even need a primer. It sticks firmly in no time.
Moreover, the product is one that you can count on for long-lasting sealing power.
Apart from siding, other areas around the house need sealing—for instance, doors, windows, and trim.
If you’re hoping to seal these areas as well, you’ll find the versatile quality of the Osi caulk pretty useful. This product is compatible with not only wood but also drywall, metal, rubber, and plastic.
11. Red Devil Duraguard Kitchen & Bath Caulk
The last caulking product on this list is the Red Devil Duraguard Kitchen & Bath Caulk.
So, you don't have a caulking gun or don't want to use it? This is a perfect selection for you. It is a product that allows you to caulk gaps and cracks speedily without having to use any tool. You just open the tip and seal those gaps right away.
The reason why many DIYers believe this is the best caulk for Hardie board is quite simple. This product is incredibly easy to use. Firstly, you don’t need a gun. For small touch-ups and quick jobs, it is the ideal sealer.
Secondly, the tube is designed to give you an easy time. Unlike some tubes, which are hard to press and therefore difficult to use, this one is quite soft. Pressing it and getting the caulk flowing is easy-peasy.
What’s more, the caulk flows smoothly and lays down in a perfect bead.
Have you ever used a caulk that was not very consistent? Maybe it had clumps that clogged up the nozzle or that made spreading a nightmare.
Well, what you get with the Red Devil Duraguard is quite different. This product doesn't contain clumps, and it sure doesn't clog the nozzle.
Thanks to the lovely and smooth consistency of the substance, spreading it is a piece of cake. You don’t even need special tools because your finger will do the job efficiently.
If you want high-quality caulk that adheres to multiple surfaces, this one is for you. You can use it on marble, wood, fiberglass, ceramics, metal, vinyl, and whatnot.
The product has a biscuit color, although you can choose white or clear when purchasing. Also, you can paint it to match the color you want.
Comparison Table Of Caulk For Hardie Siding
Flex Shot Rubber
DAP Acrylic Latex Caulk
Siliconized acrylic latex
GE Sealants & Adhesives
Gorilla Heavy Duty Ultimate
GE Window & Door Max Shield
Red Devil Lifetime Ultra 230 Caulk
White Lightning 3006 All Purpose
Siliconized acrylic latex
Sashco Big Stretch High
Red Devil 0848 Premium
Siliconized acrylic latex
OSI Quad Max Caulk
Siliconized acrylic latex
Red Devil Duraguard Kitchen
Siliconized acrylic latex
Caulk for Hardie Siding Buying Guide
Caulking as a home improvement project is a serious matter. Using the right products is essential because it not only adds aesthetic value but also solves issues and boosts your home's durability.
When looking for the best caulking for cement board, you want, first, a product that works. That means it should be able to shut the gaps effectively and keep the weather out. Moreover, it should be durable.
Here are the factors to consider.
1. What it is made of
Caulk is available in a range of material. The main materials include acrylic latex, siliconized acrylic latex, pure silicone, and butyl rubber. Some products are made of one of these materials while some are formulated from a mixture of two or more of the materials.
The reason why you should pay attention to what the product is made of is simple. Different materials have varying properties that make them suitable or unsuitable for certain situations.
For instance, pure silicone caulk is not usually easy to paint on. However, this material is excellently water-resistant, and therefore perfect for areas that are often exposed to moisture, such as the bathroom and kitchen.
On the other hand, acrylic latex is paintable. Therefore, it makes an excellent choice for areas such as the siding and around doors and windows.
Ever seen white siding with a different color in the gaps where the sidings are joined? It's not a good image, is it?
This inconsistency occurs when the caulk that was used to seal the gaps was of a different color from the siding.
How do you prevent this issue?
It is a no-brainer – just be sure to color-match the caulk with the siding.
There are two ways of doing that. The easy route is to make sure the caulk you buy is the same color as the color of your siding. If your siding is white, be sure to get white caulk. That way, the gaps in the siding will not even be noticeable.
The second way is to get a paintable caulk. Most acrylic latex and siliconized acrylic latex caulks are compatible with paint.
After applying the caulk, you will get a paint that matches the color or the siding and apply it over the sealed gaps. Some people prefer to apply paint to the entire siding and gaps for better consistency.
The gaps in siding do not stay the same size. Weather elements like wind, rain, and heat from the sun cause the gaps to move and change in size.
I don’t know if you’ve ever noticed cracks on caulk. Cracking is a result of the caulk being rigid and intolerant to gap movement. Unfortunately, cracking can create quite an eyesore.
That is why you need a flexible caulk. When the caulk is flexible, it conforms to the movements of the gaps.
4. Easy Cleanup
Like with any home improvement process, mistakes are bound to happen. When you misapply the caulk, then you have to remove it and apply properly before the caulk dries.
However, removal may be easy or difficult, depending on the product you're using.
The reason why DIYers prefer water-based caulk is that it is easy to remove with water. Therefore, fixing errors is not difficult.
Ease of cleanup is also crucial for when you’re done applying the caulk, you’ll need to remove it from your hands and tools.
Let me guess. You’re applying caulk to shut the gaps and keep water, bugs, dust, cold breeze, and/or light out.
The right caulk for cedar siding is that which is able to keep these elements out. It should be able to create a watertight seal that totally keeps the water out.
Moreover, it ought to be resistant to UV rays, mold, mildew, bugs, and more. There also should be no gaps left for the cold to get in through.
When you apply caulk to those gaps and cracks, you’re certainly not looking to have to keep caulking them from time to time. You expect that for years, the seal will keep water and other elements out.
In that spirit, you ought to go for a caulk with sufficient adhesive properties. The product should be able to hold for a long time no matter how much wind, water, or heat is hitting it.
My advice is that you get a siliconized acrylic latex caulk as opposed to just acrylic latex. The infusion with silicone helps the product stick better and boosts the waterproofing capacity.
People Also Asked (FAQs)
Q1. Can I Caulk James Hardie Siding?
Ans: It is typically recommended that where the siding meets the trim, a gap should be left of 1/8 inch. Also, between every two sidings, space is typically left that can be an entry point for water.
Caulking these gaps seals them and prevents the entry of water and other elements that can damage the siding.
Q2. What is the Right Caulking for Cement Board?
Ans: Most DIYers and contractors use acrylic latex. That is because the material is easy to use. You can smooth it effortlessly even with your fingers. Also, clean up with water is a cinch.
Acrylic latex is flexible, moving with the changes in the gaps, and thus it doesn't crack or get deformed.
To have it even better, consider getting siliconized acrylic latex. This kind of caulk is stronger and more resistant to weather. Furthermore, silicone boosts flexibility.
Siliconized acrylic latex remains flexible for years, making it ideal for gaps that are susceptible to extension, twisting, and contraction.
The superior binding property of silicone makes siliconized acrylic latex ideal for virtually any substrate, from brick and stone to wood and metal. It’s a product that you can use both indoors and outdoors.
Q3.Can I Apply Siding Caulk to Other Parts of the House?
Ans: That depends on the nature of the caulk. Mostly, acrylic latex caulk applies to other areas inside and outside your house. Most of the pro stretch caulk used for siding can also be used around doors, windows, trim, countertops, bathroom and kitchen sinks, vents, crown molding, and more.
Q4. What is the Purpose of Caulking?
Ans: Caulk is an essential product for building as well as home improvement. Its incredible benefits are undeniable.
For instance, do is water getting in through gaps around the house? You can use caulk to seal the gaps and prevent the water from getting in.
Caulk also comes in helpful from preventing elements like cold air, dust, sunlight, and more from entering the house. If there are cracks around your sinks, countertops, or other areas in the house, you can use caulk to close them up.
Q5. Must I Remove the Old Caulk Before Putting in More?
Ans: New caulk doesn’t stick to old, dried caulk. If you apply fresh caulk to some that is already cured, tiny spaces will be left that will allow the moisture to seep in. That will negate any benefits that you were looking for when caulking.
To help the caulk stick and ensure the created seal is watertight, be sure to remove the old caulk.
Open gaps in Hardie siding can lead to disasters. When it rains, water gets into the gaps and causes damage to the siding and the underlying material. Moreover, the dampness becomes an attraction to infestation by mold, mildew, and insects.
That’s why getting the best caulk for Hardie siding is such an important step.
The product gets in the gaps, sealing them so that elements like water, dust, cold air, heat, and more, don’t get in. By sealing off the gap and keeping elements from getting in, you keep the insides protected from damage.
But when shopping, be sure to get the right product. Good caulking for cement board should be effective, weatherproof, and durable. The review above is meant to make choosing easy for you. With any of the products listed, you can be sure that the gaps will be sealed effectively.