Voice of Best Things

Reviewing the Best Fire Blocking Sealants of 2017

Everyone wants a protected environment to live in. To ensure that their families and properties are safe against the dangers of fire, people spend so much on firestop drywall, and other insulating methods.

Firestop Drywall

What they tend to fail is the tiny gaps which makes the spreading of fire easy and all the money that they have invested on making the house fireproof goes down the drains. To avoid such a thing, fire blocking is important.

There are different types of fire blockings which are being used in different applications. While drywall or structured panels are ideal for filling up the large and visible gaps in the panels, there are many tiny gaps which tend to get overlooked.

When it comes to matters of fire and its rapid spreading, it really does not matter whether the gap is big or small. As long as the fire gets a passage, it would extend forward and take the walls and ceilings under its grasp.

To seal the small gaps, the best option that is available in the market are fire blocking sealants , which seals the gaps in a way that fire fails to find any passage forward, get s a gradual cut in its oxygen supply and eventually get extinguished naturally.

Even if it does not get extinguished naturally, it certainly cannot spread to a wide area rapidly, which helps in controlling reducing damages as well as giving people the time to evacuate the floor or the building.

Quick Links to Our Picks of Fire Blocking

1. 3M CP-25WB+/10.1 10.1 Oz. Fire Barrier Sealant
2. Handi-Foam FireBlock Polyurethane Foam Sealant

*The above links lead to current prices and customer reviews on Amazon.

1. Quick Links to Our Picks of Fire Blocking
2. How to Choose the Best Fire Blocking Sealant
3. Reviews of the Best Fire Blocking Sealants

3.1 3M Fire Barrier Sealant CP 25WB+
3.2 Handi-Foam FireBlock Polyurethane Foam Sealant

4. Frequently Asked Questions
5. Conclusion

How to Choose the Best Fire Blocking Sealant

While choosing fire blocking material, one has to consider a couple of things. The first of these things include the size of the gap that needs to be sealed. If the size is big enough, you may need to use solid fire proof blocks to keep the fire from spreading out rapidly. One can also use mineral wool firestopping material without violating the fire break wall regulations as that is also allowed by the code.

Fire Blocking Material

Fire Proof Blocks

The factors that are important while choosing the best fire blocking material or sealant are as follows.

  • It should be able to give protection against fire for the maximum duration of time.
  • It should comply with the codes like ASTM E84 or ICC-ES evaluations
  • It should be easy to apply
  • It should have excellent adhesive properties so that it bonds with different surfaces easily. Examples of different surfaces would include concrete, wood, plastic, metal, and cable jackets etc.
  • It should be visible so that the framing inspectors do not find it difficult to identify them during the inspection process
  • Should be intumescent in nature so that it seals the gap properly with limited quantity
  • It should have excellent caulk rate

Reviews of the Best Fire Blocking Sealants

There are many different types of fire blocking sealants available in the market. However, not all of them do a commendable job in restricting the fire from spreading through the penetrations. Basis the points mentioned above, I have reviewed the most popular sealants and found the following ones really good. I recommend the usage of these sealants to get 100% protection against rapid spreading of fire.

3M Fire Barrier Sealant

3M CP-25WB+/10.1 10.1 Oz. Fire Barrier Sealant (Pack of 1)
Price: --
32 new from $8.370 used

The 3M Fire Barrier Sealant CP 25WB+ is a latex-based, gun grade, intumescent fire sealant that not only blocks fire but stops transmission of airborne sound waves as well. This fire sealant is prepared basis the formula that lets it form a monolithic layer once it dries up.

It is highly effective in controlling the spread of flames, smoke and other noxious gases before, during or after a fire event. It needs to be applied with standard caulking equipment.

The sealant can be used for a number of applications which include but are not limited to blank openings, metallic and non-metallic pipes, single and bundled cables, HVAC ducts and vents, static construction joints, insulated pipes and floor and floor-ceiling assemblies.


  • Provides fire protection for up to 4 hours
  • Highly effective and easy to install
  • Water-based and paintable formula makes it easy to apply and clean up
  • Acts as a barrier to airborne sound transmission as well
  • Manufactured in USA


  • Come users have complained about the caulk being very dry which makes it difficult to be applied by the conventional caulking gun

This sealant is free of halogen which lets it expand to a minimum of 3 times its dried volume. With impressive caulk rate, this is definitely one of the best fire sealant products that I would recommend for domestic or even commercial fireblocking projects.

Check Price & Availability The 3M Fire Barrier Sealant

Handi Foam FireBlock Polyurethane Foam Sealant

When it comes to finding a convenient, effective and economical way to install fire blocking in wooden frame residential constructions that would also comply with the mandated building code, the Handi Foam FireBlock Polyurethane Foam Sealant is the only name that I could think of. The sealant is formulated to delay or prevent the spread of fire flames and fire smoke through concealed penetrations from room to room or floor to floor.

The product can be used effectively to fill in gaps in and around vents, ducts and pipes which make it provide a complete fireblocking solution for different applications.


  • Highly economical sealant option
  • R-Value of 4.5 per inch cured
  • Great for stopping air leaks and drafts
  • Can be sprayed overhead as well
  • Cans designed for quick and easy dispensing when used with gun foam tools
  • The product passes ICC-ES evaluation for Type V residential product for fire blocking


  • Cannot be used as a firestop in commercial fire rated walls

The orange color coded foam makes it easily visible which is particularly useful during jobsite inspections. The foam is expandable, which makes one 24 oz. foam can equal the product volume of 30 tubes of caulk.

Handi Foam FireBlock Polyurethane Foam Sealant Recommended By Us

Frequently Asked Questions

What is fire blocking?

Fire blocking is the method of sealing the joints and openings in the fire rated walls and floor assemblies. The blocking of fire is done by means of fire blocking material or sealants which are categorically formulated to cease the spread of flames and smokes in case of a fire breakout.

What if I do not opt for installing Fire blocking?

You can certainly do that. However, not opting for fire blocking basement walls can lead to a couple of things. Firstly, you would be exposed to the threat of a rapid fire breakout without getting the time to call the firemen or evacuate the building quickly. Secondly, you would also fail the framing inspection.

Fire Blocking Basement Walls

What materials can I use as a fire block?

As per fire blocking code, the approved materials for a fire block include structured panels, drywall, unfaced fiber glass, and mineral fiber batts. However, for the mineral wool fire blocking material, it is important that the batts should be able to fill the entire cavity or gap on the wall to a minimum height of 16 inches. It is also important that they are installed in a secure way so that they would not move.

Fire Blocking Code

Mineral Wool Fire Blocking

How do I install Fire block?

Installing fire blocks is quite simple. All you have to do is identify the gaps and apply fire block insulation material there. If the gap is too big, you need to cut out strips of the fire blocking material and fix there by means of glue.
If the gap is small enough, you can simply apply some fire blocking sealants that will fill the gap and make the fire rated wood blocking safe from any sort of rapid spread of fire flames.

Fire Block Insulation

Fire Rated Wood Blocking

Why is fire blocking important?

Fire blocking is important as it restricts the spreading of fie flames in case of a fire breakout. This stops the fire from getting spread and cause extensive damage. This gives enough time to the occupants of the building to evacuate the premises so that the firefighters can start working on extinguishing the fire. This also reduces the damage of properties in case of a fire.


It is definitely true that no one can change the future but when it comes to the safety of our lives, people try to take every possible measure to protect themselves against hazards. That is why I recommend the use of fire block wall and sealants to ensure that the property and lives of family members are safe against the dreadful consequences of a fire breakout.

Fire Block Wall

Being thoughtful pays big time and that is why I think it is time that you become thoughtful and get the best firestopping sealant for your basement and house without any further delay.

Home Voice

Leave a Reply