Wildland Urban Interface

Rules & Regulations for Dry, Fire-Prone Areas

by AC Galeon, Southern California territory manager, DaVinci Roofscapes


Wildfire. It’s one word that causes panic for many homeowners, especially those in dry, fire-prone areas. If you live in hot spots throughout the country, then you need to know about Wildland Urban Interface (WUI) products and codes. Having that knowledge will help to ease some of your potential customers’ panic.


What is WUI?

WUI is the transition between undeveloped wildland, or unoccupied land, and human development. This includes houses, retail, schools, and other development. An interface fire can jump from a man-made structure to natural materials. This would include trees and shrubs. The opposite can also occur. A wildfire can jump from a forest to man-made buildings.

The basic requirement of WUI is that the exterior of a structure be ignition-resistant. In addition, it must be able to resist the entry of flying embers and fire radiation during a wildfire. This is especially important for roofs. What does this mean to homeowners and roofing installers? Most importantly, you should check local WUI code requirements and rules. You want to know which approved WUI products are best for a home exterior.

You may be surprised at the number of wildfires happening right now across the country. The National Fire Protection Association (NFPA) tracks those fires and maintains a WUI zone map. In addition, NFPA has a FireWise USA® program, which helps communities reduce wildfire risks and prevent infrastructure losses.


Home Ignition Zones

Communities should be aware of the actions they can take in the immediate zone, intermediate zone, and extended zone to make their homes safer. The immediate zone is the area 5’ or closer to the exterior the home, and is the most important zone. Homeowners and building owners should keep roofs and gutters free of dead leaves, debris, and pine needles. Also, replacing and repairing loose or missing shingles or roof tiles will help mitigate fire danger. Residents should move anything that can burn, such as mulch, plants, leaves, needles, and firewood piles, from exterior walls.

The intermediate zone is the area 5’-30’ from the immediate zone. Landscaping in this zone can influence and decrease fire behavior. Residents should keep lawns and grasses mowed to 4”, remove vegetation under trees, and prune trees 6’-10’ from the ground.

The extended zone is the area 30’-100’ from the intermediate zone. This zone serves to interrupt a fire’s path and keep flames smaller and on the ground. In order to help in these ways, the extended zone should be cleaned of ground litter and debris. Dead plants and trees, as well as plants and trees around storage sheds and out-buildings, should be removed.


Products vs. Systems

You may already know there are code requirements for fire-resistant roofing in some areas of the country. Class A is the highest rating, while Class C is the lowest. Understanding the ratings is important for everyone. Meeting WUI standards is about more than just having a Class A rated roofing product. First, there are the fire-resistant roofing and underlayment materials. These create the total roof system. Second, WUI rules and regulations take into consideration the site where a structure is built. This includes the distance of the building from forests, trees, or even shrubs. In other words, it’s about creating a safe zone around a structure.

In recent years, there has been an increase in restrictions on types of building materials used in many West Coast states. These regulations help builders and roofing professionals create homes that can stand up to flame spread. However, the materials can only help so much. In the big picture, building materials are fragile, and many are also potentially flammable. This is especially true for wood products, which is why real wood products often get the thumbs down for so many roofing, decking, and siding projects.

Even when treated, real wood can burn. That’s one reason why many insurance companies do not want to offer homeowners insurance to people with real shake roofs. In addition, it doesn’t take a wildfire to be right next to a cedar shake roof to make it burn. Flying embers from up to a mile away can land on a cedar roof. When that happens, it can start a fire.


What Do I Need to Know?

If you are installing a new roof, check first with your local building codes. Also, if you’re in an area with WUI code requirements, check on those, too. For those who are replacing their real cedar roof, code requirements may stipulate you install a WUI-compliant roof. A Class A fire-resistant roof may cost more than other roofs. However, in the long run, it’s an investment to keep your home safer.

If you are looking for WUI products for your customer’s roof, consider these tips. Go to the roofing manufacturer’s website. Look for details on product fire ratings and search for WUI products information and flame-resistant details. Explain the entire proposed roofing system to your customers, including the underlayment and its fire rating. Give a complete picture of fire ratings for every part of the roof system.

Remind customers to contact their insurance agencies to ask about restrictions and discounts. Some homeowners can gain a discount on homeowners insurance with a fire-resistant roof. Advise clients to cut back shrubs, trees, and vegetation that can serve as a dangerous fuel source. Remind homeowners to inspect and clean off the roof regularly. It’s important for homeowners, designers, and roofing contractors to all work together to make sure a home is as safe as possible against fire hazards. By understanding the resources available in terms of WUI products, communities can reduce wildfire risks and prevent infrastructure losses.