California homeowners are working to integrate fireproof building into their construction and remodeling projects.
Increased risk of wildfires is especially concerning to suburban homeowners in and near the Wildland Urban Interface (WUI), the transition zone in between unoccupied land and human development. Increased vegetation in these areas catches fire easily, which may spread to nearby homes. New construction or exterior improvements in these areas may require WUI compliant materials.
Check this map from CalFire to see if your home is in a Fire Hazard Safety Zone. There are three wildfire risk zones, very high, high, and moderate.
Roofing and Siding for Fireproof Building
Start fireproofing from the top. During a wildfire, embers and ash are airborne, and may land on the roof. If the roof ignites, the fire could spread quickly down the siding to the rest of the house.
Roofing Types for Fireproof Building
Class A fire resistant roofing is required for any home in a very high risk FHSZ. However, if your home is located in any FHSZ, Class A roofing is recommended. In addition to fireproof roofing materials, look for a roof design with a steep pitch, so that embers roll off easily. Keep gutters clear of flammable materials.
The following materials meet the flammability standards for Class A fire resistant roofing:
- Fiber Cement. These shingles are made from a combination of cement, wood, and sand, and are Class A fire resistant for up to four hours.
- Tile. Traditional clay tile is also durable, and fire resistant. Openings around the edges and eaves need to be blocked with fireproof screening.
- Slate. Not only is slate classic and elegant, it is also noncombustible. It is heavy, so make sure that your home can support a slate roof before installation.
- Fiberglass-Based Asphalt Shingles. This economical roofing option covers approximately 80% of the country’s roofs. Coupled with fire-code-compliant underlayments, asphalt shingles are extremely fire resistant.
- Recycled Rubber Tire. For a lightweight, eco-friendly roof that is also fireproof, check out shingles made from recycled rubber tires.
- Metal. Metal, or metal tiles with a fire resistant underlayment are lightweight and low maintenance.
Siding Types for Fireproof Building
Class A Fire Resistant siding, as described by CalFire, is required in any high risk FHSZ. Generally, wood siding is not recommended in any FHSZ, particularly those areas that are considered a very high fire risk. However, if the home is located in a low or moderate risk FHSZ, treated wood siding may be an option, though it needs to be retreated every five years.
The following siding materials are fireproof or fire resistant:
- Fiber-cement siding. This type of siding doesn’t require extra finishing or hefty installation costs. It comes in different colors and finishes to customize the exterior look of your home.
- Cultured Stone.
- Masonry. Masonry, such as brick or stucco, is a classic home exterior choice that is naturally fire resistant, and also has insulating properties. Unfortunately, these options are also the most expensive. Also, masonry transfers heat to the siding underneath, so you will need a layer of heat and fire resistant material between the masonry and siding.
- Stone Veneer. Stone creates a beautiful, natural look that is also fireproof. Make sure to use a fire-rated mortar.
- Exterior Insulation Finish Systems (EIFS). This finish may look like stucco, but it is actually acrylic-impregnated cement over fiberglass, with a foam insulation layer in between. It is both heat and fire resistant.
Decking and Framing for Fireproof Building
Wood is traditionally used for decking and framing materials. There are fire resistant options to keep the structure of your home solid even during a fire.
Wood decks can bring the fire right to your doorstep. In a low or moderate FHSZ, treated lumber decks may be an option, as long as the wood is retreated regularly.
In any FHSZ, it’s best to choose a fire resistant decking material, such as:
- Composite Decking Material. A fire-resistant synthetic material comes in many finishes and colors.
- Structural Insulated Panels (SIP’s). These panels are made of engineered laminate with a solid foam core and OSB or plywood sheathing. In addition to being non-combustible, these sturdy panels are also resistant to mold and water damage.
- Autoclaved Aerated Concrete Blocks. These blocks are made of aluminum and concrete. They are half the weight of concrete, and can be cut with a saw.
- Insulated Concrete Forms. These polystyrene blocks fit together, and can be used as a fire resistant decking material.
The framework of your house can be sturdy and fireproof with the use of these materials:
- Autoclaved Aerated Concrete Blocks. These multi-purpose blocks offer one hour of fire protection per square inch.
- Insulated Concrete Forms. These polystyrene blocks fit together to form a solid, lightweight, fire resistant framework.
Windows and Doors for Fireproof Building
No matter how fireproof the home’s exterior, wildfires can breach the fortress if the doors and windows aren’t sufficiently fire resistant.
Skip single pane windows. They are not fire, or heat resistant and will offer little protection from a wildfire. Also avoid acrylic skylights, as they melt in high temperatures.
Instead, opt for double or triple pane windows. Fire resistant window glazing is also available. For even more fire protection, install windows with a pyrostop window filling. Generally, small window panes offer better fire protection than large panes.
Instead of wood garage or exterior doors, use steel doors with a fire resistant core and a protective resin coating. A sweep on the bottom of the door will help keep smoke out, and be energy efficient. For the interior, choose steel or treated wood doors with fire resistant cores.
Insulation and Systems for Fireproof Building
What’s inside the walls may be just as important as what’s on the outside. Careful planning includes hidden elements, like insulation and sprinklers.
Cellulose, chemically treated with borate to make it fireproof, is an excellent alternative to fiberglass or cotton insulation. Cellulose is made of recycled paper, chemically treated, then sprayed into the walls. Once it is placed, it acts as an excellent insulator.
Water and Power
Programmable sprinklers on the roof are useful to extinguish fires. Assume that you may lose electricity, so have a generator on standby.
Other Exterior Strategies for Fireproof Building
There are other ways to protect and fortify your home from the threat of wildfires. Take fire risk into consideration as you plan landscaping. Keep brush and debris away from the home. Consider lining the perimeter with crushed rock to create a fire barrier.
At Drafting Cafe Architects, your safety is our primary concern. Our award winning team of architects, contractors, project managers, and designers work with clients to come up with code compliant, lifestyle friendly construction to keep you and your home safe from wildfires. Please contact us today for an estimate on your remodel or addition.