Why the material of your roof can mean life or death for your home.
Roofs are something we don’t think about a lot. They’re up and away, out of sight, out of mind. But, our roofs basically are the most vulnerable parts of our house. Think about it: when it rains, snows, or hails, your roof is the one of the only things keeping the elements outside.
Not to mention, so many crucial parts of a home are linked to the roof. Chances are you have vents for your plumbing penetrating your roof that helps push air in so it drains quickly. You may also have your HVAC, bathroom fans, and other vital breathing ventilation up there.
So, what does that mean in a high risk wildfire zone? It means that not having the proper roof materials can literally rain fire from above.
Let’s think about fire and the different ways it can spread. One of the ways that we’re concerned about is through something called ‘firebrands’ or embers. These are tiny, hot, flammable particles from a fire that can travel up to a mile away. The closer the wildfire gets to you, the more embers are landing on your property.
Now, if a firebrand hits the siding of your house, it will most likely fall down into the perimeter area of your home (which is why defensible space guidelines state you shouldn’t have anything flammable within 5 feet of your exterior walls). But, if the wind carries firebrands UP, it’s going to land on your roof where it can ignite and burn your house down from the top.
If your roof is made out of cedar shake or other unrated wooden materials, that’s a very high risk of ignition, and a nice little pile of firewood for wildfire to feast on.
Roofing materials can be broken up into ‘classes’. Class A ignition resistant is considered the cream of the crop, and the safest kind of roof you can have. Class C roofs are the lowest rating for any kind of ignition resistant roofing. Unrated roofs are considered to be the most dangerous, and are illegal to have in some high risk wildfire areas.
Let’s break down what these classes mean:
-
Class A
The most effective against ignition, lasting the longest before any other class. This group includes materials such as clay, concrete, slate, synthetic (tiles that mimic the look of wood or stone), metal, and certain asphalt shingles (not all of them).
Class B
This class puts up a fair fight, but ignites sooner than its Class A counterparts. To get a Class B rating, roofing materials need to last a least an hour before ignition (which may sound like a lot, but isn’t ideal if your house will be getting pelted by firebrands for hours or days at a time). Some of these materials are some categories of shingles, and some pressure treated wood shake.
Class C
This category is similar to asking your cousin to come pick you up from an airport during rush hour: it might seem safe on the surface, but it’s probably not up for the task. Class C is the lightest fire resistance of all, and it only lasts 20 minutes before sparking a blaze. Some class c roofing is really common on cabins, which is a huge issue if they’re deep in the woods. Class C materials include wood shake, plywood, and particle board roofing.
Unrated
If you have an unrated roof in a high risk wildfire area, you have no classification of any fire protection. Most insurance companies will have you upgrade this before even covering you. Nevertheless, unrated means that it has not been tested for fire safety prior to installation.
Unrated roofs are probably older, and in need of replacement or repair anyways. There is no guarantee of any fire resistance with unrated roofs: that’s why they’re unrated!
-
Because your roof is one of the biggest surfaces your home has, (and has a bunch of nooks and crannies where dry vegetation can turn into fire fuel), it’s probably one of the most important steps you can take when preparing your home for wildfire. Replacing your roof is incredibly expensive, but so is losing your entire house, or being denied insurance at all.
It’s important to know that not all is lost: wood shake roofs CAN be upgraded to Class A with pressure-impregnated flame retardant. There’s also additional roofing underlayment and other gutter-guarding products you can buy to protect your roof without needing to fully gut and redo the whole thing, but sometimes there is no true workaround for a Class A roof.
Some high-wildfire risk counties also have programs that give grants to home owners to upgrade their building materials. Ask your local fire department, or Firewise USA group to see if they have any leads on grants, contractors, or wildfire mitigation experts who can help you get the work done.
Roofs are some of the most exposed and brutalized parts of our homes. Try your best to invest into materials that will give your home a fighting chance. If you’re thinking about ways your home can be affected by wildfire and you want to be really thorough, you can take our free wildfire assessment to see how your home stacks up (and how you can keep it safe) at assessment.faura.us.
