Sep 30

Ember Showers

How can something so tiny cause so much destruction?

An ember by itself seems so innocent – one tiny glowing speck.

But make no mistake, embers or “firebrands” can ignite your home as easily as direct flame contact. Embers are usually pieces of twigs or branches that have caught fire. Think of a campfire – when you burn the wood, little pieces of glowing fire disappear into the air around you.

In fact, in recent fires around the country as well as Boulder County, many of the homes destroyed ignited through ember showers. Ember showers are similar to a snowstorm, but made of embers instead of snow. The tell-tale sign of a home ignited through embers is a pile of ashes surrounded by green trees. The trees stay green because the fire never reached the area around the house.

But embers can travel several miles ahead of the actual fire due to wind and intensity of the fire. During windy conditions or larger fires, so many embers are produced, that they produce ember “blizzards”. When those embers hit your house, they can set it on fire through various methods. Embers will accumulate in the same spots around your home that pine needles, leaves, snow, and other organic debris naturally collect.

Do you have pine needles in your gutters or on your roof? Those pine needles provide tinder fuel to start a fire.

Do you have gaps in your siding? Embers can enter through gaps as small as ¼ inch. They can also pass through vents you have on the side of your house, like your dryer vent or gable vents. Embers will ignite the siding, framing, dryer lint, and other flammable materials that could be in your attic.

Finally, embers can ignite your house at the base of your walls. If your wood siding comes all the way to the ground, embers will hit the side of your house, fall to the ground and smolder. This problem is exacerbated by pine needles, mulch or other combustible vegetation you might have within the first five feet around your house. This video by the Insurance Institute shows how quickly a house can ignite through ember showers.

So what’s the solution?

By completing the home retrofit work prescribed by our mitigation specialists, you can mitigate the risks posed by ember showers. In fact, performing home retrofit work is as important as doing forestry work when it comes to protecting your home.

If you’ve received your Wildfire Partners assessment report, you’ve probably seen the comments:

“Add metal angle flashing to the junction of your deck and wall to prevent ember ignition.”

“Seal gaps greater than 1/8 inches to prevent embers entering your home.”

“Expose your foundation to prevent embers from igniting your siding.”

By looking at different areas of your house and the area immediately adjacent to your house, you can systematically address these vulnerabilities.

Roofs: Make sure your roof is a Class A rated roof and is in good condition. Replace missing shingles that provide an opportunity for embers to ignite the plywood underneath. Check your roof and gutters regularly to find and remove pine needles and branches.

Siding:  Caulk or patch any gaps or holes greater than 1/8-inch wide in your siding which could allow embers to set your home on fire. Look for and remove bird’s nests or houses which provide an opportunity for ignition. Seal off openings under porches.

Create 4-6 inches of exposed foundation at the base of your walls, so your wood siding doesn’t meet the ground. If that’s not possible, consider adding a noncombustible material at the base of your siding such as metal flashing or fiber cement board.

For extra protection, consider replacing your wood siding with noncombustible siding like fiber cement board or stucco.

Decks: Install metal flashing at the junction of the wall and  your deck surface. Make sure you remove all vegetation and combustible items below your deck. For extra protection, enclose the area below your deck with 1/8-inch metal screening.

Finally, focus on the first five feet around your home. Remove vegetation whenever possible and maintain a noncombustible barrier like gravel, stone or cement, where embers can smolder without igniting your house, garage or shed. Using weed barrier over your soil before laying stone or gravel will save you a lot of maintenance time down the road. Pay special attention to the area under your windows as the radiant heat from fire can break your window glass and allow fire to get inside your home.

Remember that mitigation is an ongoing process and you will need to regularly maintain your home and the areas around your home. The dry climate of Colorado will cause wood siding to dry and crack further. Trees near your home will drop needles on a regular basis. Plants will grow back and need to be pruned.

It’s a good idea to check your home on a regular basis to keep up with home retrofit work. May is Wildfire Awareness Month and is a great time to focus on these repairs before the height of the wildfire season.

By putting in the work now and performing regular maintenance, you can significantly lessen your risk of home ignition from ember showers.

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  1. Robert Beebe
    October 2, 2020 at 11:33 pm · Reply

    Your article is very valuable. I’ll check it all out. But I have a question. You say to “enclose the area below your deck with 1/8-inch metal screening.” Do you mean immediately under the planks of the deck or somewhere lower than that?


    • Leslie Brodhead
      October 3, 2020 at 3:00 pm · Reply

      Robert, the area we are referring to is the area underneath your decking in line with the outside of the deck. If you enclose that area with 1/8-inch metal screening, it will prevent embers from getting accumulating underneath your deck.

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