Firestop caulking on the South shore of Montreal.

Unlike residential or commercial caulking that is designed to improve the building and prevent water damages and air infiltration, firestop caulking plays a very important role in protecting the building against fire, and that is its entire purpose.

What is firestop caulking?

Fire caulking, also referred to as firestop sealant, is a sealing product made from fire-resistant materials. It is used for sealing seams, gaps, joints and openings within horizontal and vertical fire resistance walls, floors, ceilings and around fire-rated doors to provide optimal fire safety for buildings and structures.

Fire caulking slows or prevents the spread of flames, smoke and toxic fumes.

The application of fire caulking is mandatory by local building codes of the Regie du batiment du Quebec and in Canada.


What is a firewall?

A firewall is a fire-resistant barrier used to slow or prevent the spread of flames and smoke. Firewalls are installed through or between buildings and different types of structures.

Fire rated door: A fire-rated door also referred to as fire-resistant door is a door designed to impede or prevent the spread of fire and smoke.

How does fire caulk stop the fire?

Did you know that it only takes 30 seconds for a small flame to turn into a full-blown life-threatening fire and only 4-5 minutes to spread within a building?

If fire finds its way to electrical systems and HVAC components, it can grow rapidly, destroying the entire property and becoming fatal to the building’s tenants.

The firestopping system (Fire-rated doors, horizontal and vertical firewalls and fire sealants) aims to stop or delay the fast spread of fire and smoke by locking the fire in compartments within the building. 

Since fire can spread through an opening as small as a pencil nib, the firestop caulk ensures that the openings are sealed and are fire-resistant.

Firestop caulking expands when heated and reaches a temperature of 200 degrees. As it expands, it fills the penetration or joints it is applied to and prevents the fire and smoke from spreading into other areas, preventing damage and potentially saving lives.

A proper firestop system can:

  • Save lives – By allowing enough time for people to evacuate the building.
  • Minimize or prevent loss of property.
  • Provide more time for the fire department to control the situation.
  • Protect people in other parts of the building.

Who Needs Fire Caulk?

Condo buildings, commercial and industrial buildings require an installation of fire systems and fire caulking. Business owners should ensure that they follow the local fire code laws to avoid any issues and protect the employees and clients. Buildings that are vulnerable to a fire or pose a higher risk of a fire breaking out.

Fire caulking is often required around penetrations. Penetration is an opening around a floor or wall. There are two main types of penetrations: Through penetrations and membrane penetrations.

A through penetration has an opening on both sides, whereas a membrane penetration has an opening on one side only. Both types of penetrations require fire caulking. Joints and perimeter barriers also require fire caulking.


Due to its important role in protecting a building against the spread of flames and smoke, the application of firestop caulking is more complex.

Preparing for the installation of firestop sealants:

  • It is essential to perform a short examination of the work area.
  • Professional caulkers must verify that all openings and penetrations are in perfect condition and are prepared to apply the fire rated sealant.
  • All surfaces to which the fire sealant materials will be applied must be cleaned and free of substances (such as dirt, oil, rust, water repellents, etc…) that may prevent proper adhesion.
  • The installation of firestopping materials must be done at the right temperature and humidity level recommended by the manufacturer.

Proper Application of fire caulks and sealants

For proper installation, the installer must verify:

  • Whether mineral wool must be installed as a first step
  • That the firestop caulk is installed at the appropriate depth
  • The rating of the firestopping sealant is matching the rating of the wall or floor assembly. (Standard ratings include 1, 2, 3, or 4-hours. )
  • That the product is tested for the type of penetration in the barrier.
  • The inspection of the fire protection system is crucial during and after installation to ensure that the installation was done correctly according to the Regie du batiment du Quebec’s highest standards.

To learn more about commercial caulking, click here


Firestop products

Calfeutrage Apex is using high performance firestop sealants and caulks by leaders in the fire resistance industry.


Hilti firestop sealants.

Hilti is a worldwide leader in manufacturing of fire resistant sealants and caulks according to firestopping rating codes. Here are some of the Hilti fire caulks and sealants that we use:

  • FS-ONE – Temperature resistance-40°F to +212°F (–40°C to +100°C)

FS- ONE Is a firestopping sealant that expands when exposed to fire. It can be applied to steel, copper and EMT pipes, Cable bundles, plastic pipes, HVAC penetration.

  • CP 601S – Temperature resistance –40°F to +320°F (–40°C to +160°C)

A silicone firestop sealant is applied in fire-rated joint applications and pipe penetrations and provides excellent movement capability. Mineral wool or backer must be installed before the firestop sealant. For a smooth finish, the sealant should be tooled.

  • CP 604 -Temperature resistance –40°F to +320°F (–40°C to +160°C)

A Silicon firestopping sealant for use through penetrations and construction floor joints. This sealant is self-levelling and requires no tooling. It has excellent compression properties and can be used for: sealing cable bundles, metal pipes, expansion joints, and penetrations in small or large openings.

  • CP 606 – –22°F to +176°F (–30°C to +80°C)

This is an acrylic firestopping sealant that is very flexible. The CP 606 is installed in fire-rated joints, expansion joints, HAVC penetrations, Metal pipe Cable bundles, top wall joints.


Tremoco firestop sealants and caulks.

Tremco sealants are fire rated silicone and acrylic.

Who can install firestop caulk?

The installer of a fire caulking has to be an individual that was trained and qualified by the firestopping sealants manufacturer to install fire sealants according to the manufacturer’s requirements.

Calfeutrage Apex Inc has trained team members that install firestopping caulk to all types of structures, on the South Shore of Montreal. For a free quote please call: 438-288-0338 or email us at:  info@calfeutrageapex.com