Best Sealant Between Concrete and Wood: Top 5 in 2024

Sealant Between Concrete and Wood

Sealing the space between concrete and wood protects both surfaces from moisture and weathering. You’re inviting many problems if you don’t seal the space between your concrete and wood.

Water can penetrate the concrete, causing the wood to rot and the concrete to crack. The elements will also take their toll, causing both surfaces to deteriorate over time.

A suitable sealer can prevent unsightly stains and scuffs on concrete surfaces. Using the best sealant between concrete and wood will keep the area clean and neat instead of an unfinished construction project. Here we will share some top sealants that can make a great barrier between your concrete and wood.

Rust-Oleum Water Based Polyurethane Sealant

Key Features:
👍 Gloss finish
👍 Dries in 30 minutes
👍 31.25 sq ft coverage
👍 Low odor
👍 Excellent clarity

Sikaflex Elastomeric Polyurethane Sealant

Key Features:
👍 Urethane-based
👍 High elasticity
👍 Limestone color
👍 Non-staining
👍 Weathering resistance

3m TALC 540 Polyurethane Adhesive Sealant

Key Features:
👍 Multi-purpose bonding
👍 Permanently elastic
👍 UV resistance
👍 60-90 skin time
👍 Moisture-curing sealant

Can You Secure a 2×4 to Concrete with Sealant?

urethane caulks

Polyurethane sealant is a joint product that can be used to adhere a 2×4 to the concrete foundation. It is easily applied with a caulk gun and forms a strong bond that can hold up against weathering and temperature changes.

The sealant is weatherproof and can be used indoors or outdoors. It can prevent mold from growing in cracks and gaps. Since it is clear, you won’t need to worry about it marrying your foundation wall. This clear concrete sealer is flexible, which helps to prevent cracking and crumbling.

Can You Attach Treated Lumber to Concrete with Sealant?

It is possible to adhere treated lumber to concrete with a sealant. The level of adhesion will depend on the type of sealant used, as well as the roughness of the concrete surface. Sealing any concrete cracks or holes before attaching the lumber will also help to create a stronger bond.

You can adhere treated lumber to concrete with screws or nails rather than with adhesive alone. It will provide the strongest possible hold and help prevent the lumber from warping or becoming detached over time.

Can I Use a Sealant to Seal a Large Gap?

polyurethane caulk

Sealing a large gap can be tricky and depends on the gap’s size and the type of sealant you are using. Most sealants will work for small gaps. For larger gaps, you may need to use a stronger sealant or take additional measures to ensure the gap is sealed.

You need to clean the area around the gap with a wire brush or another type of cleaner. It will help the sealant to adhere better to the surfaces. Using a caulk gun, apply the sealant evenly into the gap.

Once the sealant has dried, you should apply a second layer for extra protection. Allow the second layer of sealant to dry completely before using the area.

Top Reviews on the Best Sealant between Concrete and Wood

heat resistant

Sealing the gap between concrete and wood is important to prevent water damage and decay. There are many sealants on the market, and it can be hard to choose the right one for your project.

To help you choose the best concrete sealant for your needs, we’ve compiled a list of top reviews from experts in the field. Whether you’re looking for an affordable option or a high-quality sealant, we’ve got you covered.

1) Rust-Oleum Water Based Polyurethane Sealant

Rust-Oleum brings out this polyurethane sealant as quick drying, water based sealant. This product resists stains and scratches well. It can be used on wood, concrete, or metal and covers up to 31.25 sq ft.

The sealant is also clear, making it a good choice for DIY projects that require a natural look. With soap and water, you can easily clean it.

What Makes This Product Helpful?

Rust-Oleum water based polyurethane sealant is a clear, thin finish that goes on evenly without puddling. It has a calm shine and virtually no smell once it dries. The surface gets a shiny and protective finish.

It is an easy to use sealant that protects polymer clay charms from dirt and moisture. You’ll get a good finish and keep your surface looking new. The product is also suitable for use on reclaimed beams and thirsty wood.


  • Has a nice clear and thin finish
  • Goes on evenly without pondering a calm shine
  • No noticeable smell once it dried
  • Protective and shiny
  • Excellent for glazing polymer clay charms
  • Can be used on exposed reclaimed beams


  • When spread, brush lines appear but disappear quickly

2)  Sikaflex Elastomeric Polyurethane Sealant

This sealant is a urethane-based product that needs a high level of adhesion. The sealant is also resistant to aging and weathering, making it a great choice for outdoor projects. It is non-staining, making it easy to clean up any messes.

Sikaflex is able to move 35% of joints. This means that it can be used in both vertical and horizontal joints and will still maintain its elasticity. It can also be painted with rubber, water, and oil-based paints.

What Makes This Product Helpful?

The sealant is very durable and strong and will hold well for a long time. Due to its flexible consistency, it is ideal for sealing around curved surfaces.

Sikaflex elastomeric polyurethane sealant resists water and moisturizer. It also disappears on darker surfaces, making it appropriate for use on surfaces like wood or concrete.

You can use it indoors and outdoors. It can seal up to ½ gap strongly, making it ideal for residential applications.


  • Extremely durable and holds strong
  • Has flexible consistency
  • Resists water and moist
  • Disappears on darker surfaces
  • Strongly seals gaps up to ½ inch
  • Ideal for indoor and outdoor use


  • Need to push a lot to get the sealant out

3)  3m TALC 540 Polyurethane Adhesive Sealant

Using this sealant, you can bind concrete and wood together with ease. As it is permanently elastic, it will stretch and move with the attached surface.

The sealant is designed to prevent water and moisture from entering the gap between the concrete and wood. It is also UV resistant, meaning it will not be damaged by sunlight. When moisture is exposed, it bonds with the surface and cures.

What Makes This Product Helpful?

When using TALC 540 adhesive sealant, it is important to keep in mind that it is thick and durable. Basically, it will provide a strong bond between surfaces and is resistant to wear and tear.

3m TALC 540 polyurethane adhesive sealant is also sticky and waterproof, making it ideal for use in wet or humid environments. The material is designed to provide a better seal than latex.

 It is also strong enough to support its own weight even when it curves downward and can be applied vertically if necessary. You can also use this sealant to repair plastic water troughs, as it gives them a nice, clean appearance.


  • Thick and durable
  • Sticky and waterproof
  • Seal better than latex
  • Can be applied vertically
  • Gives a nice, clean, tapered look


  • This product is difficult to re-use
  • Difficult to remove from hands and clothes

4) Tremco High Performance Polyurethane Sealant

Tremco offers this sealant for concrete and wood that cures with moisture. It has a gun-grade finish. This product is ideal for both indoor and outdoor uses, as it forms a durable and watertight bond.

Due to its permanent flexibility, this sealant can move with the surface without cracking. Once it is cured and no longer visible, it can be painted over so that it does not stand out.

What Makes This Product Helpful?

The Tremco high performance polyurethane sealant is designed for larger joints. It is durable and can withstand the elements well.

It provides a watertight and durable seal between concrete and wood. The concrete floor sealer will not come off easily, meaning that it can stand up to the rigors of even the most challenging applications.

When finished, it appears textured for a more appealing look. If you want a finished look, you can paint it after it’s cured.  You can use it for siding on the inside and outside of your house.


  • Ideal for larger joints
  • Won’t come off without cutting it
  • Paintable on unpainted concrete once cured
  • Finish with texture for a better look
  • Can be used outside
  • Suitable for siding


  • Can be challenging to control the spread

5) OSI – HENKEL CORPORATION Self Leveling Concrete Sealant

The sealant by OSI – HENKEL CORPORATION features self-leveling characteristics. It is extremely flexible and capable of forming a seal that is highly resistant to abrasion.

Due to its resistance to a variety of weather conditions, it makes an ideal joint filler between concrete and wood. A low VOC formulation makes this sealant safer for the environment and able to withstand extreme temperatures.

What Makes This Product Helpful?

OSI – HENKEL CORPORATION Self Leveling Concrete Sealant is designed to protect concrete from weathering and general deterioration. It remains flexible for expansion and contraction and can be applied in various weather conditions.

The sealant is also good at adhering to pressure-treated wood and untreated concrete. It is designed for horizontal concrete repairs and will dry to a rubbery texture. You can use it as a threshold to secure lumber.


  • Easy to use after prepared properly
  • can be used to secure lumber as a threshold
  • Suitable for horizontal concrete repairs
  • Self-leveling and dries to a rubbery texture


  • Takes days to weeks to cure based on materials 
  • Not easy to use for vertical surfaces

These are just some of the products you may want to consider when finding a concrete sealant that also bonds to the wood. These sealants have been chosen for their effectiveness and ease of use. With so many options available, you’re sure to find the perfect sealant for your project.

Factors to Consider When Buying Sealant Between Concrete and Wood

penetrating sealers

Polyurethane sealant can be used to fill cracks and gaps between concrete and wood. If you’re looking for the best sealant for concrete to wood, there are a few things you need to consider.


The size of the area you’re trying to seal will determine the amount of sealant you need. You need to have the right size of sealant when you are sealing concrete to wood.

If you have a crack that is too big, the sealant will not be able to fill the crack and do its job. In small cracks, the sealant will cover the crack, but it will be ineffective.

It’s always best to avoid caution and buy more sealant than you think you’ll need. This way, you won’t run out in the middle of the project and have to stop to buy more.


Most sealants will shrink as they cure. You’ll want to select a product with little to no shrinkage to avoid gaps and cracks forming in your seal.

Many factors can cause the sealant to shrink. Thermal expansion and contraction are common when the sealant is exposed to extreme changes in temperature. This can be a problem in both hot and cold climates.

Another factor that can cause shrinkage is improper application. If the sealant is not applied correctly, it will not bond properly with the surface and will start to shrink.

UV exposure can also reduce the sealant’s performance. This is because UV light breaks down the chemical bonds in the sealant, causing it to become thinner and less effective.


Most sealants come in a variety of colors to match the surrounding area. The most popular colors are clear, white, and gray. Yet, there are many other colors available as well.

Clear sealants are the most popular because they let the natural color of the wood show through. White sealants are also popular because they provide a clean, finished look. Gray sealants are becoming more popular because they have a modern look.


Sealants can be permanent or temporary. It needs to be effective in repelling water and also needs to be able to withstand the harsh UV rays of the sun. A sealant that is not permanent will soon wear away, becoming vulnerable to damage.

A good sealant will form a permanent bond that will not break down over time. It will also provide an effective barrier against water, dirt, and other debris, ensuring that it looks its best for years to come.

Odor and VOCs Level:

Some sealants can be quite smelly when first applied because they contain volatile organic compounds (VOCs). The level of VOCs in a sealant can vary from product to product.

A low VOC sealant is essential when sealing concrete to wood because it eliminates the chance of toxic fumes. Some sealants contain high levels of VOCs or volatile organic compounds.

When these sealants are used, the VOCs are released into the air and can be inhaled. This can lead to serious health problems, including headaches, dizziness, and respiratory irritation. In some cases, it can also cause cancer.

On the other hand, low VOC sealants do not release harmful fumes into the air. They are much safer for contractors and homeowners. These sealants are also better for the environment.

Ease of Use and Clean:

Some sealants are easier to apply than others. You use a caulking gun, putty knife, or airless sprayer to apply sealant. Using a caulking gun is the easiest and most popular method. For small projects, use a putty knife. An airless sprayer is good for large projects.

Some sealants can be difficult to remove, requiring strong chemicals or hours of scrubbing. Others come off easily with just soap and water. A good sealant should be easy to clean with mineral spirit, denatured alcohol, or white vinegar.

What Do You Use Polyurethane Sealant for?

concrete countertop

Polyurethane sealant is a versatile product that can be used for a variety of home improvement projects. It can be used to seal cracks and gaps in both wood and concrete, and it can also be used to waterproof surfaces.

It will prevent moisture damage and insulate against noise and vibration. Polyurethane sealant can be used to create a variety of finishes, including high-gloss, semi-gloss, and matte.

Everything from pipes and plumbing fixtures to boats and automobiles can be sealed. This sealer can protect metal surfaces from corrosion and coat fabric surfaces to make them resistant to stains.

Can You Use Sealant Between Foundation and Sill Plate?

Applying sealant between the foundation and the sill plate can protect it from the elements. The sill plate is the horizontal board that sits on top of the foundation.

Using the sealer will help keep them separate. In this way, you can prevent water damage to your foundation and discourage pests from entering your home.

To apply sealant properly, you will need to use a caulk gun or airless sprayer and apply a generous amount of sealant around the perimeter of the sill plate. After applying sealant, you can use a putty knife to smooth it out and create a seamless bond between the foundation and sill plate.

Does Concrete Sealer Prevent Mold?

Does Concrete Sealer Prevent Mold

When applied properly, sealers can effectively prevent mold and mildew growth on concrete surfaces. The concrete sealer, made from polyurethane, is a clear or tinted coating applied to protect it from weathering, staining, and wear.

Mold and mildew can cause significant damage to concrete surfaces if left untreated. It not only discolors the surface but can also cause cracks and other structural issues.

Concrete sealers work by creating a barrier between the concrete and the environment. This barrier helps to prevent moisture and other contaminants from penetrating the surface of the concrete, which can lead to mold growth.

Is Polyurethane Sealer Toxic?

Many people are concerned about the safety of polyurethane sealers, especially regarding children and pets. While it is true that polyurethane sealer contains chemicals that can be harmful if inhaled or ingested, the risk is relatively very low.

The exposure is usually quite limited, and the sealer dries quickly and emits very little fumes. Most polyurethane sealers are water-based, which means they are less likely to contain harmful chemicals. 

Always read the label carefully and follow the directions for use. When used properly, polyurethane sealer can provide a safe and effective way to protect your concrete floors.

How long are Polyurethane Fumes Toxic?

How long are Polyurethane Fumes Toxic

The length of time that polyurethane fumes are toxic varies depending on the product used. In general, it takes 5 to 7 days to decrease the toxicity of the fumes. But water-based polyurethanes take about 3 weeks to off-gas completely, while oil-based polyurethanes can take up to 4 weeks.

When polyurethane is drying, ventilate the area well and avoid using strong chemicals or cleaners. Once the sealer has dried, it is safe to resume normal activities.

What to Use to Seal Between House And Concrete?

Many materials can be used to seal the space between your house and concrete. The most common materials are urethane caulks, rubber weatherstripping, and Insulation foam.

Urethane caulk or polyurethane sealant is the best choice for sealing cracks and gaps around windows and doors. It is easy to apply and creates a waterproof barrier lasting many years.

Weatherstripping is another good option for sealing the space between your home and the concrete surface. It is less durable than urethane caulk but can be easily replaced if it wears out.

Foam insulation can be used for sealing large gaps and spaces. The seal is tight, but it can be difficult to remove if you ever need to make repairs. Foam insulation is the most expensive option, but it will last the longest and provide the best insulation.

How Do You Seal a Gap Between Concrete and Wood with Sealant?

How Do You Seal a Gap Between Concrete and Wood with Sealant

Caulking with polyurethane sealant is the best way to fill gaps between concrete and wood. Sealing this gap can help to prevent water damage, insect infestation, and drafts. The following are the steps that you need to follow to seal a gap properly:

Step 01. Clean the Gap:

Start by using a wire brush to remove any loose debris, dirt, or dust from the surface. Use a putty knife to remove any old caulking or sealant from the joint. It adheres properly and creates a lasting seal.

Step 02. Install Backer Rod:

Depending on the gap between your concrete slab and wood size, you may need to apply a foam backing rod first. This will help to fill any large voids and provide a smooth surface for the sealant to adhere to.

If you are working with a large gap, you may need to insert a foam backing rod before applying the sealant. Insert the rod into the gap and use a utility knife to trim it to size. Or use a caulk gun to apply a bead of sealant along the joint.

Step 03. Apply Sealant into the Gap:

Cut the tip of the caulk tube at a 30 or 45-degree angle. The flow of sealant will be smooth and even due to this technique. 

Hold the tube 45° or 30° off the ground and slowly squeeze the trigger as you move along the length of the gap. You can apply it with a putty knife also. Be sure to apply an even layer of sealant approximately 1/4 inch thick.

Step 04: Use a Caulking Tool:

Use a caulking tool or your finger to smooth out the sealant. It creates an invisible and weatherproof seal. Be sure to wipe away any excess sealant immediately with a damp cloth.

Step 05: Allow Sealant to Dry:

Most polyurethane sealants will take 24-48 hours to cure fully before exposing it to water or excessive moisture. Open the windows and turn on the fans to help circulate air and speed up the drying process. 

During this time, avoid walking or driving over the sealed area. This will ensure that the final product has a professional appearance.

When to Apply Sealant between Concrete and Wood?

When to Apply Sealant between Concrete and Wood

The best time to apply sealant is after the concrete driveway or slab has cured for at least 28 days. It will allow the sealant to bond with the concrete and provide waterproof protection

If possible, apply sealant on a day when the weather is warm and sunny. This will help the sealer to cure properly.

Once the sealant has been applied, wait at least 24 hours before walking on the surface or placing any furniture on top. Allowing the glue to cure fully will help ensure that it provides long-lasting protection for your concrete and wood surfaces.

How Long will Polyurethane Sealant Last?

When properly applied, polyurethane sealant can last for 5 to 10 years. The specific lifespan of a sealant may vary depending on the type of surface it is applied to, the amount of traffic it receives, and the climate conditions it is exposed to.

Generally, sealants exposed to harsh weather conditions or heavy traffic will need to be replaced more frequently than those not. Regularly inspect surfaces sealed with polyurethane and repair or replace any damaged or failing sealant.

Now you know everything from applying sealant between concrete and wood to its lifespan, which concludes our article. We hope you can not choose the best sealant between concrete and wood and make a robust waterproof barrier.

Best Sealant Between Concrete and Wood: Top 5 in 2024

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