Are Modular Homes Safe In A Fire?

In case of a fire, modular homes are as safe as most traditionally built constructions. All modular homes are built to comply with the minimum safety requirements established by the building codes. These codes certify a minimum safety of the construction in case of a fire. However, adhering to the building codes isn’t enough to ensure a house is fire resistant, being modular or traditionally built. Therefore, to build a fire-resistant house, we should go beyond the minimum requirements set by the building codes.

Building a modular home that is fire-resistant:

• Choose fire-resistant building materials
• Protect the openings
• Design a fire-stopping landscape
• Detach the garage

The way we build a modular home will define how much resistance the house will show in front of a fire. Choosing the right construction materials and elements, as well as laying out the buildings and surroundings properly is essential to keep the flames away and slow down the time it takes for the house to burn out. Still, even when we have built a fire-resistant modular home, there are some actions that we can take that will help us increase the protection against fire. 

Modular homes are built up to the Building Code’s regulations. Does this make them fire-proof?

Modular homes are built by putting prefabricated modules together, which sometimes raises confusion making modular homes look like moveable constructions. Still, modular homes are always built as permanent houses: once the modules are delivered to the building site, they are permanently attached to their foundations. Therefore, these constructions are treated just like any traditionally built home and are required to adhere to the building codes. 

The building codes are, according to FEMA, “the minimum design and construction requirements to ensure safe and resilient structures” [1]. Every modular home is built according to the building codes, which offer some sort of protection against fires. However, these codes vary from one location to another, being more or less strict depending on where the modular home is built. All the building codes are based on the International Code Council® (ICC) [2], though depending on the needs and even the government these regulations change. 

Some states such as California take wildfires very seriously and have adapted their building codes to ensure fire-resistant constructions. Other states like Oregon or Colorado on the other hand, still have very loose regulations [3] and the houses built in those areas won’t be as fire-resistant when built to accomplish the minimum building code’s requirements. Therefore, even if the building codes offer some sort of protection against fires, this protection will vary from one area to another. 

Building a fire-resistant modular home

When building a modular home, we shouldn’t solely rely on the building codes to ensure fire resistance. Since modular is only a construction process it doesn’t define the materials or design, leaving a wide variety of options to choose from and allowing us to build, if we wish a fire-resistant house. Below we have listed the most important things to consider when building a modular home with the intention of being fire-resistant.

Choose fire-resistant building materials

The most fire-resistant materials are those that can withstand the heat of the fire for a longer period of time without melting, breaking or collapsing. Fire-resistant materials aren’t usually fire-proof, though they grant enough time for the occupants to leave the house safely and, hopefully, for the fire to be put down before great damage occurs. The fire resistance of every material is rated in minutes, representing the amount of time it takes until the material starts melting or breaking. 

• Timber: Timber is one of the most common construction materials, both for traditional and modular construction. It is combustible and wooden houses are believed to burn easily, though dense woods offer quite a good fire resistance. It is possible to build a timber structure with 30, 60, and even 90 minutes of fire resistance [4]. Additionally, timber is usually treated to increase its resistance to fire by impregnating it with fire-retarding chemicals [5].

• Concrete: A popular construction material given its sturdiness that also shows good resistance to fire. The thermal conductivity of concrete is very low, which means that it can sustain the exposure to the flames and heat for a long period of time, being possible for a concrete structure to resist for 60 minutes while exposed at 1,832ºF (1,000ºC) [5]. 

• Steel Frame: Some modular homes are built with a steel frame structure. Steel is non-combustible and therefore won’t catch fire non spread the flames. Though it doesn’t handle high temperatures very well, steel will soften and lose strength when exposed to the high temperatures of a house fire. Therefore, it is essential to protect steel with coatings or materials that are more fire-resistant such as intumescent coating, intumescent boards or cementitious coatings [6]. 

Protect the openings

The openings of the house have to be carefully built and protected to maintain the safety of the building in front of a fire. Any opening allows burning embers to enter inside the house, easing the spread of the fire indoors. Therefore we should pay special attention to windows, doors, chimneys and vents. Windows are delicate elements that consist mainly of glass, if the glass breaks the flames can easily enter the house. Glass can break either from the impact of flying debris or as a result of extreme heat. To avoid this, the windows chosen to build a modular home that is fire-resistant should be dual-paned with tempered glass [7]. 

Similar to windows, doors connecting outdoors with indoor spaces have to be built to be more fire-resistant and reduce the possibility of spreading the fire inside the house. Choose doors that are built of solid timber and no less than 44mm thick. Also, having a self-closing device will help ensure the door is always closed [8]. Chimneys and vents have openings easily inviting burning embers to enter the house. it is essential to cover these apertures with a metallic screen. Avoid covering them with plastic or fiberglass since these materials can easily melt or burn.

Design a fire-stopping landscape

A fire-stopping landscape is especially important to keep wildfires away from the modular home and it should be carefully designed as well as maintained to ensure its efficiency. Try to prioritize hard over vegetal pavements, choosing concrete, stone or gravel. These types of pavements will help maintain a dry-vegetation zone area which is key to avoiding the spread of the flames. 

Not all plants burn easily in front of a fire, some plants are considered to be fire-resistant because they don’t ignite. These plants can still be damaged or die in front of a fire, though they won’t contribute to spreading the fire. There is a great amount of fire-resistant plants from which some of the most commonly known are lavender, sage, daylily, red maple and red oak [9]. However, one of the most important aspects to consider is the placement of the vegetation. In order to protect the house from the flames, it is essential to keep the vegetation away from the windows, vents, decks or sidings [10]. 

Detach the garage

Garages, storage sheds or workshops often contain highly flammable substances or materials such as gasoline or solvents. In case of fire, these substances will easily spread the flames and even increase the temperature of the fire. Keeping these spaces detached from the main house will highly reduce damages in case they catch on fire. 

In case we can not build a separate structure for these activities, it is essential to install fireproof features that help mainly avoid the spreading of the fire from the garage to the main living areas. This means installing fire-rated garage doors and fire-resistant-rated walls (commonly known as firewalls) [11].

Actions you can do that will help protect your modular home in case of a fire

Building a house that is fire-resistant is the most effective way to reduce the damages caused by a fire in a passive way. Before building a modular home we have the opportunity to choose the most optimal materials and design strategies to help maintain a fire-resistant house.  However, to increase the safety in front of a fire, it is very helpful to count on some active protection. 

These are actions that every modular homeowner can integrate:

• Install smoke alarms: Smoke alarms have the sole purpose of notifying us of the presence of smoke. This device won’t stop or avoid a fire, though it will inform us about it, granting us enough time to escape [12]. 

• Get a Fire extinguisher: While a fire extinguisher won’t be of great help in case of a wildfire, it is an amazing tool to stop a small kitchen fire from spreading and burning the whole house.

• Keep rain gutters clean: Rain gutters can easily accumulate dry leaves and debris which are highly combustible. If flames or burning embers reach dirty gutters, the debris will set on fire easily compromising the safety of the overall home [13].

• Remove combustible items around the house: It is common to store combustible materials such as wooden looks very close to the house. Avoid storing it underneath the deck or right by the house sidings to reduce the possibility of flames touching the construction.

• Keep a well-maintained yard: A well-maintained yard can set the difference between a house that burns and a house that stays away from the flames. Keep the yard well-watered, prune regularly and clean up, especially to get rid of dry leaves or branches [10].

References:

1. (2021, September 29) 5 reasons why building codes should matter to you FEMA https://www.fema.gov/blog/5-reasons-building-codes-should-matter-you
2. I-Codes Code Adoption Map The Wagner Companies https://wagnercompanies.com/i-codes-code-adoption-map/
3. (2020, November 25) Rebuilding after a wildfire? most states don’t require fire-resistant materials NPR https://www.npr.org/2020/11/25/936685629/rebuilding-after-a-wildfire-most-states-dont-require-fire-resistant-materials
4. Introduction to timber & fire CTI Firehub https://timberfirehub.co.uk/introduction-to-timber-fire/
5. Mahajan, B. Fire Resistant Materials used in building construction Civiconceptshttps://civiconcepts.com/blog/fire-resistant-building-materials
6. Understanding the fire resistance of structural steel CLM Fireproofing https://clmfireproofing.com/how-does-fire-affect-structural-steel/
7. Fire in California – Windows University of California. Agriculture and Natural Resources https://ucanr.edu/sites/fire/Prepare/Building/Windows/
8. Information Sheet – Fire Resistant Front Doors Wandsworth https://www.wandsworth.gov.uk/media/2963/information_sheet_-_fire_doors.pdf
9. (2006 August) Fire-resistant plants for home landscapes Oregon State University, Washington State University, University of Idahohttps://www.firefree.org/wp-content/uploads/2016/02/Fire-Resistant-Plants.pdf
10. Fire Smart Landscaping Ready for wildfire https://www.readyforwildfire.org/prepare-for-wildfire/get-ready/fire-smart-landscaping/
11. (2021, August 8) 3 ways to fireproof the garage Fleximounts https://www.fleximounts.com/blog/3-ways-to-fireproof-the-garage/#page
12. Smoke Alarms – Why, Where and Which? Consumer Product Safety Commission https://www.cpsc.gov/s3fs-public/SmokeAlarmWhyWhereandWhichCPSCPub559RevisedJuly2016PostReview%282%29.pdf
13. Homeowner’s wildfire mitigation guide – Gutters University of Californiahttps://ucanr.edu/sites/Wildfire/Roof/Edge_of_Roof_Issues/Gutters_785/