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How to use a smoke odour sealer for fire damage restoration

What if your house catches fire and now you have fire damage and smoke and other odours? What do you do to begin the restoration process and minimize the exposure to harmful pathogens that may be harmful to your health?

What does Barefoot Concrete have to do with Australian Fire Protection Services? We have a product called Y863 Smoke Odour Sealer which can be used in fire restoration projects.

Fire damage can be devastating. It can wreak havoc on a home and significant work and cost will be required to restore it.

Fire damage restoration is where you reverse the destruction of a fire and return the home to its former state. applying coatings to walls and surfaces is a crucial part of that process.

Smoke damage sealers are a special kind of coating that adhere to damaged surfaces, block stains and prevent detrimental odours from lingering smoke after a fire, protecting a home from the after-effects of the fire.

You may not realize how important sealers are to doing a successful fire restoration project. However, smoke sealing after a fire is an integral part of preparing the property for reuse. Also, you will need to cover damage after cleaning and also do contaminant removal and ensure deodorization and the absence of additional harm.

It’s more complicated than it looks. From picking the right primer and differentiating between sealers to the process of painting over fire-damaged walls, there is a lot you need to know about smoke odour sealers.

When to use a sealer

Let’s start with a question: How useful can sealers be and when is the right time for fire restoration professionals to use them?

There are specialist companies that exist to remediate the damage from fire and other disasters and they can use smoke sealers in a variety of ways.

What are smoke sealers? Smoke sealers are intended for use only after all cleaning and contamination removal has been completed to the satisfaction of all involved parties. They are not intended to cover up poor restoration work.

The point at which a smoke sealer should be applied – and even if one should be applied at all – will depend on the individual situation. Factors like the type of fire that occurred and the extent of the damage will dramatically affect the choice.

Australian fire protection services have responded to many fires, many of which were structural fires. With home structure fires occurring, and other structure fires occurring, the scale of national fire damage is significant, and the need for restoration is crucial.

Now we get to the meat and potatoes of it, fires occur for different reasons, and the type of chemical and physical damage differs from structure to structure:

  • Cooking equipment causes approximately 47% of home fires
  • Heating equipment is responsible for 15%
  • Electrical equipment accounts for 9%
  • Smoking materials account for 5%

In addition to the presence of chemicals responsible for beginning the fire, the fire itself produces a variety of toxins that contaminate the building – these may also affect the choice of when and if to use a sealer.

The question arises, why use a smoke odour sealer or smoke and odour encapsulant at all?

The heat, flames and uncontrolled combustion of fires lead to the production of a mix of harmful chemicals, including gases, liquids, aerosols and partially oxidized particles, some of which adhere to surfaces and corrode materials.

Even after the fire is extinguished, toxic odours and volatile emissions can continue to damage the structure and make the area hazardous.

In combination with effective cleaning and contaminant removal practices, sealers can be an effective way to prevent the return of smoke odours or stains and serve as a primer by adhering to difficult surfaces so that a final paint coat can be applied.

It is important to note that sealers are not cleaning agents in themselves, and they should never be used in an attempt to cover odours or contaminants that should have been treated and removed.

Sealers serve to bind surfaces, block pores and prevent the return of odours, stains and additional damage. They should only be used after proper, thorough cleanup and contaminant removal.

Ok, now that we understand the basics, what’s the difference between sealers and encapsulants?

Even in the professional restoration industry, people sometimes use the terms “sealer” and “encapsulant” interchangeably, but they should not. The two types of coatings have very different purposes, and confusing their uses could lead to problems.

What is the difference?

Encapsulation describes the process of enclosing or repressing something, so it makes sense as a term used to designate wall coatings and primers.

Technically, sealers encapsulate porous surfaces, stopping odours and damage from returning. 

Encapsulants perform a similar task by being applied to walls to permanently manage and abate the presence of asbestos and lead-based paint in older buildings.

While on the surface, these two types of coating appear to serve the same purpose by preventing further damage through the release of odours and chemicals, they are fundamentally different in terms of process, which is where the danger lies in confusing them.

  • Encapsulant: A coating that is used to manage exposure to the underlying materials or contaminants. This term is commonly used when referring to managing exposure to asbestos or lead-based paint.
  • Sealer: A coating that is applied after all contaminants have been removed and surfaces thoroughly cleaned in order to prevent the reoccurrence of damage such as stains or odour.

You can only apply sealers to surfaces after a thorough cleaning and removal of contaminants, and they bar the return of damage.

Encapsulants, on the other hand, are put directly over the undesirable substance, covering it rather than removing it.

During restoration, contaminant removal always comes before coating with a sealer, so encapsulants and sealers should not be confused or used interchangeably in the fire damage restoration industry.

Now that you have been informed and are familiar with the basic purpose and usage of sealers, how can you figure out what is the best primer for smoke damage?

Each kind of sealer comes with its own specific features and limitations, so it is important to select the type that best meets your needs based on your specific project. 

Here are some questions to consider when evaluating the features, functions and benefits of a sealer for restoration.

Does it stick?

The first step to evaluating the benefits of a particular sealer is observing whether it adequately adheres to the surface you coat.

If the sealer does not stick well, it is not particularly suited to the surface, and it will not make a good choice for aiding restoration.

Will it suppress fire-related odours?

Half of a sealer’s job is to suppress the return of unpleasant or harmful odours from smoke and fire-related chemicals.

When selecting the right sealer, make sure it is effective in suppressing existing odours and inhibiting those scents from returning through the pores of the surface. If not, the coating will be just for show – and that is not useful to your purpose.

Can it seal stains and residues reliably?

The other half of a sealer’s functionality rests in blocking the spread of stains and residue.

The goal is to keep the decontaminated surface clean and presentable, restoring it to its former state, so the risk of bleeding smoke stains should be reduced as much as possible.

An effective sealer must prevent unsightly and unwanted stains from spreading if there is potential for this to occur.

Is it breathable?

If the structure you restore experiences internal moisture of any kind in keeping with its function, make sure the sealer you select will allow for some release of water vapour.

If you use an incompatible coating in an area that will see moisture buildup, it could lead to other problems with your restoration job in the future, including water damage and warping of the walls.

Will it simplify cleanup complications?

During your restorative process, consider where the use of sealer fits in. If you have been able to clean, decontaminate and deodorize without many remaining issues, sealing is one of the final steps to ensure restoration, so make sure it simplifies the process rather than adding unnecessary steps.

Sealers should be suited to the environment in order to streamline the process of returning the structure to its pre-damage state. If adding the sealer makes cleanup more difficult, it is not the right kind or it may not be needed at all.

Is the sealant sustainable for the future?

Finally, a smoke damage sealer is a step intended to ensure the sustainability of the restored area.

Make sure you select a coating that will continue to perform its purpose and hold up over time, protecting the structure from stains, odours and chemicals well into the future and giving the building a long second life.

Types of fires and smoke damage sealers

Now that you know the critical considerations involved in choosing a well-suited sealer, you should become familiar with the different categories of sealers, along with their attributes, capabilities and limitations.

Selecting the appropriate sealer for application in a particular job is a matter of balancing the capabilities and limitations with the project’s most pressing needs and considering the criteria based on preferences including price, performance, personal protective equipment (PPE) requirements and sustainability.

Available sealers are mainly differentiated based on chemical formulation, and they fit into four categories:

  • Water-based
  • Shellac
  • Alkyd
  • Fixatives

Water-based fire and smoke damage sealers

This type of sealer is made up of acrylic polymer systems sometimes blended with speciality resins in a water-based vehicle. Y863 Smoke Odour Sealer is a good example.

Some water-based solutions are specifically intended for fire damage restoration and formulated to fit its needs. Professionals typically use this category of sealer for sealing stains.

Water-based sealers are useful because they have the capability to seal smoke odour while still offering water vapour permeability, meaning they will not develop condensation layers.

They are also highly flexible and have a minimal odour and a low volatile organic content (VOC) level.

As opposed to other types of sealer, this category is relatively inoffensive to environments or occupants with high chemical sensitivities, and it does not need any special handling for excess waste disposal. It also has no extra PPE requirements.

Water-based sealers are versatile and relatively low-cost. It is also extremely safe, posing no threats in terms of flammability and combustibility.

For all their excellent qualities, water-based sealers do possess a few limitations, including:

  • A greater preparation period requirement
  • A softness to their cured film
  • A variability in drying time
  • A changeability in stain-blocking performance – while some sealers are effective with only one coat, others may need two applications or more

They are also sensitive to material types, meaning high-solvent topcoats can deteriorate them, and they can be repelled by high-silicone content on surfaces.

You cannot use this type of sealer at a surface and air temperatures below 10 degrees Celcius, and not all water-based solutions are applicable in the same way, meaning some require brushes or rollers, while others come as airless sprays.

Shellac fire and smoke damage sealers

Composed primarily of processed lac resin, which is secreted by insects native to Indonesia and India, this sealer is created through suspension in alcohol.

In the past, shellac has been the most commonly used sealer in fire damage restoration because of its prime ability to control fire odour. In fact, it boasts a decades-long history of successfully sealing smoke odour in treated surfaces.

This type of sealer is available through DIY supply stores or retail paint stores, and it is the most expensive type.

Shellac possesses multiple useful characteristics, including its ability to be cured and applied at much lower temperatures than other sealer formulations – down to -12 degrees Celcius. It can also:

  • Adhere to tough or difficult surface conditions
  • Accept almost any type of topcoat as a primer
  • Dry in less than 30 minutes for maximum restorative efficiency

When dry, the cured finish is especially hard in comparison to other sealers and is ideal for stopping stains.

In addition to its commendable qualities, shellac possesses some limitations, so make sure its characteristics fit with your project.

This particular sealer is impermeable to water vapour transmission, meaning it can trap moisture and form a barrier of condensation.

It can also be brittle when exposed to direct impact, making it an unsuitable choice for outdoor use. Be mindful that shellac requires extra attention to detail with denatured alcohol cleanup, and exposing its vapours to ignition can be a hazard.

Shellac also needs special handling – in the form of solvent recycling – for the disposal of excess material.

While it serves to bar smoke odours, it also leaves behind an unpleasant lacquer odour for up to a week, which can require carbon filtration to eliminate completely.

It also requires PPE for application, such as protective respiratory equipment to make inhalation safe, and you should pay attention to regulations regarding maximum VOCs, which can make it unavailable in certain areas.

Alkyd-based fire and smoke damage sealers

Alkyd primers are oil-based and typically used more frequently for sealing stains from water damage.

These are technically designated for fire restoration use, but they can fulfil these kinds of applications.

Water-based alkyds and other hybrid coatings are currently emerging within this category. Alkyds are typically available in DIY Supply Stores and retail paint stores, and they are one of the least expensive formulations of sealers.

Alkyds have a number of positive attributes, including their toleration of difficult or imperfect surface conditions, excellent stain-blocking abilities and quick-drying capabilities.

This sealer is also easy to sand, and after thorough curing, it accepts almost any oil- or water-based topcoat as a primer.

Some of the alkyd-based sealers’ limitations include:

  • Uncertain permeability or lack of permeability
  • Expected VOC restrictions
  • PPE requirements
  • Flammability and combustibility
  • Persistently lingering odour
  • Specialized waste handling requirements

Alkyds also need extensive mixing before application, and they involve a lengthy cleanup process with mineral spirits, which can increase exposure to solvents and cost more in labour and productivity.

Fixative fire and smoke damage sealers

Fixative sealer formulations are especially low in solids, and they help residual particulates adhere to surfaces, keeping them from contaminating the air and becoming respirable.

This can be useful in isolating and eliminating toxins to stop further circulation after fire damage cleaning, but it is not particularly suited to avoiding further surface damage or keeping smoke stains from seeping, because it forms no tangible film.

The do’s and don’ts of smoke damage sealers

Now that you are armed with the details of sealer uses, categories and considerations, you are almost ready to incorporate them properly into your fire damage restoration projects.

Just make sure you follow these crucial dos and don’ts with any smoke damage sealer application process.


  • Consider the needs of the particular project. These may include environment, exposure, level of damage and future function of the structure. Being careless with choosing your sealer can mean the site will not reach its full restoration potential in the future, and it can lead to later problems down the line.
  • Use a product intended for fire or smoke damage. Be especially careful to select a sealer you know addresses smoke damage and odour, especially in a structure with extensive damage or a sensitive environment. Note, that some sealers – like alkyds – are intended for other purposes, so approach them with caution and always choose the product specifically designed to do the right job.
  • Pay attention to the preparation of your sealer. Some sealers require extensive mixing or safety preparation before use, and failing to follow these requirements or using them incorrectly can lead to damage or dangerous conditions. Even before selecting your sealer, make sure you know exactly what is involved in its preparation and application.
  • Perform proper cleanup and waste disposal. Some sealers are safer, while others are flammable, hazardous, high in VOC and specific about PPE and toxic waste requirements. To ensure health, safety and effectiveness, make sure you are aware of how to properly handle and dispose of all materials you use.

Do not:

  • Use sealers to cover up poor work. It is imperative that a structure is fully cleaned, deodorized and decontaminated before the application of any smoke-damage sealer. Sealers cannot cover remaining contaminants or incomplete cleanup work – they can only serve to prevent additional stain spreading and odour escape.
  • Use just any paint primer. Sealers are specially formulated for damage treatment and are the only coatings you can use to cover smoke damage and block smoke odours. Using an ordinary paint primer on smoke and fire-damaged surfaces creates an incompatible situation and will only lead to further damage to the surface.
  • Use sealers interchangeably. Every sealer has a unique set of characteristics, properties and limitations that make it more suitable to certain environments and situations. Never assume two different types of sealer will have the same effect or that you do not need to research their use in relation to the particular project. Pick the best-suited sealer and do not combine types.
  • Be careless with application and cleanup. Just like every sealer is different in properties, the procedures for preparing, applying and disposing of the coating vary with the type of formulation. Pay close attention to the directions for handling your particular sealer to ensure the coating is effective, the procedure is safe and the chemical cleanup is properly performed.

Lastly, use smoke damage sealers with care and consideration at all times, contact Barefoot Concrete to determine if Y863 Smoke Odour Sealer is the right product for your fire damage project.