The area of Prescott Arizona has been devastated these past 4 weeks with two major wildfires, the latest one took the lives of 19 firefighters. Tens of thousands of acres have burned to the ground, including hundreds of homes. I know the areas that have burned quite well and I viewed the burn sites of the Granite Mtn fire. I can tell you that very few people employed "defensible space" out in the Yarnell area. The homes and structures literally had brush & timber within an arms length of the structures. I would say that about 95% of the homes were wood framed with exposed wood siding. Some had vinyl siding while only a handful few had a brick facade. Most roofs were asphalt shingle over OSB and wood truss with exposed attic vents.

These firefighters were defending property, as the residents had evacuated long before the fire even came close to their homes. What irks me is that the people didn't do their part in creating defensible space around their homes. The firefighters have to come in and do that for them but they are under the gun with the fire encroaching.

These homes will be rebuilt and 99% of them will go right back and rebuild using the same exposed wood building methods. Roof, attic and soffit vents exposed to embers, wood siding, etc. There are better methods to rebuild in high fire danger areas and one can use concrete, stone and steel, materials that are fire resistant.

It's seems as though lessons are never learned and people go right back building as if there were no alternative building method. It's a shame.

An aerial shot showed that a single home survived while all the surrounding homes burned to the ground. The home definitely had a metal roof and it was either concrete walls or steel walls, it was hard to see the walls from the aerial shot. One thing is certain, everything around it was burned to the ground but that home was still standing.

It's the same discussion as building tornado proof homes. It's very hard to build a structure that can withstand a forest fire. Although there was a house still standing, is it structurally sound still? I agree that there should always be a an open buffer between a house and the brush or forest. We are building in the middle of the woods, but will have a decent space around the house, as well as fiber cement siding and a metal roof. We would survive a minor fire, but a really big one would probably destroy at least part of the structure. For most people, it comes down to economics. Building for that one-in-a-million scenario is just out of reach financially. I would guess that far more houses are destroyed by fires inside the home, rather than outside.

Maybe they need to re-think putting so many lives at risk to save homes built in potentially dangerous areas. Get the people out and then try to control the fire from a safe vantage point.

If a forest fire sweeps through the area and your well built home survives, do you want to live there anyway? I assume that the area doesn't look very good. But perhaps the chances of another fire are also quite low.

> These firefighters were defending property

Would they really not have been there if the homes were better built/maintained?

Posted By jonr on 03 Jul 2013 12:08 PM
If a forest fire sweeps through the area and your well built home survives, do you want to live there anyway? I assume that the area doesn't look very good. But perhaps the chances of another fire are also quite low.

> These firefighters were defending property

Would they really not have been there if the homes were better built/maintained?

The land where the homes stood will be scorched but that is where the building lot remains. People will rebuild in that same area.

Most of the fire can be fought from the sky and when the firefighters are on the ground they are usually trying to stop the fire from taking out structures that are in immediate danger. Many times they have to clear private property owners lots to make defensible space for that home.

There is no doubt that a better built structure & defensible space goes a long way as it doesn't contribute to fuel for the fire and can prevent a fire from spreading. There are many homes that have proven to survive a wildfire by simply using defensible space and fire resistant building materials.

Posted By jdebree on 03 Jul 2013 07:06 AM
It's the same discussion as building tornado proof homes. It's very hard to build a structure that can withstand a forest fire. Although there was a house still standing, is it structurally sound still? I agree that there should always be a an open buffer between a house and the brush or forest. We are building in the middle of the woods, but will have a decent space around the house, as well as fiber cement siding and a metal roof. We would survive a minor fire, but a really big one would probably destroy at least part of the structure. For most people, it comes down to economics. Building for that one-in-a-million scenario is just out of reach financially. I would guess that far more houses are destroyed by fires inside the home, rather than outside.

Maybe they need to re-think putting so many lives at risk to save homes built in potentially dangerous areas. Get the people out and then try to control the fire from a safe vantage point.

It's not difficult to build a structure to resist a wildfire and there is no reason why it would not be structurally sound after a fire nearby. Heat from a fire is due to the fuel it is consuming. If that fuel is 60+ feet away from your home. The heat around your home would not cause any issues. So with no fuel around your home to burn, the home itself is only vulnerable to embers. A concrete or steel home with a steel roof, no attic vents or at a minimum ember resistant vents. The home stands a very good chance of being unaffected by the fire.

In 2011 over 8.7 million acres of US land where burnt during wildfires. The fire last month (June 2013) in Colorado destroyed over 500 homes.

Even products like this can be applied during a forest fire to protect the home:
Thermo-Gel

Once again, it's about building smart, energy efficient and fire resistant structures. It's not difficult to build such a structure with the modern innovations that we have available. It's also not that much more money to build such a structure. People dump how many thousands into granite and other interior upgrades, what good are those things if your house burns to the ground?

HOME A:

Defensible Space
Fire Resistant Building Materials
No Exposed Attic or Soffit Vents
Metal Roofs
Available Fire Gel Foam

VS.

HOME B:

Highly combustible trees and brush sitting against home
Wood siding and exposed wood eveywhere on the exterior of the home
Exposed attic and soffit vents that allow burning embers inside the home and attic
Wood roofs
No gel foam


Home "A" can be built with very little difficulty and on the same budget as Home "B" if it is planned properly. Home "A" can give you an energy efficient and fire resistant structure that can quite easily survive a forest fire.

One of the subdivisions near these fires mandates that any new homes built must have a "rustic exterior" and it mandates a certain amount of exposed wood on the outside. Talk about lunacy. So in a high forest fire area the HOA mandates that any new homes built must have exposed wood on the exterior. Some of these HOA's are run by complete idiots, there is no other way to put it.

But the idiots think they have good taste.  So they put it in writing and then enforce it.

Posted By Alton on 06 Jul 2013 09:51 PM
But the idiots think they have good taste.  So they put it in writing and then enforce it.

The other issue is that some believe building a fire resistant home is impossible and expensive. Both of these are falsehoods that are unfortunately reinforced by misinformation. It's like the builders who think homes cannot be built air tight as homes must breathe. So they build leaky walls and roof assemblies because that's the way it's always be done.

Part of building green is designing a home that can stand for many years. Building homes that will only burn to the ground and then rebuilding them again is a waste of resources and how much "embodied energy" does that use up?

These YouTube videos from the IBHS & the National Wildlife Urban Interface Fire Protection clearly show that assemblies can be designed as fire resistant and survive forest fires if some design parameters are followed. As the videos state, making a fire resistant structure is a proven method that has the scientific data to back it but it takes a fundamental change in our thinking:


IBHS Ember Test


Firewise.Org Video

When researching I also found out that fiberglass window frames only get a Class C fire rating which is not good. That is why fiberglass windows are not used on commercial projects, as they require at least a Class B fire rating for flame spread and smoke density. Inline supposedly formulated a new resin with a fire retardant but it's pretty costly and not offered in residential applications. Steel windows are best but are pretty horrid when it comes to thermal bridging.

Posted By Lbear on 07 Jul 2013 06:02 AM
When researching I also found out that fiberglass window frames only get a Class C fire rating which is not good. That is why fiberglass windows are not used on commercial projects, as they require at least a Class B fire rating for flame spread and smoke density. Inline supposedly formulated a new resin with a fire retardant but it's pretty costly and not offered in residential applications. Steel windows are best but are pretty horrid when it comes to thermal bridging.

Lbear - you could always go with steel clad wood windows.

Here is a good Building Science article on sealed fireproof roof assemblies.

Here are a few lessons.

Don't build in high, dry, wild forested areas. Managed clear-cuts for better fire control, access and natural diversity. Practice controlled fire management. People died to save trees. The trees will grow back.

Here is a good Building Science article on sealed fireproof roof assemblies.

It's an interesting article - he doesn't believe in unvented roofs in high snow areas (plus they are expensive per R value). I think he is missing another option - ventilation that can be closed or switched off. For example, a pair of small push/pull attic fans, perhaps solar powered (and no soffit or ridge vents to add to fire risk).

I often hear of builders complaining about Building inspectors, but here is a perfect example of their worth. I built a home in the Co. mountains about 12 years ago. Larimer county had strict regulations about making sure you had a defensible space, and fire resistant exterior materials. The preliminary inspection included the Inspector going around and marking every tree that had to be removed. That and the fact that I chose the spot on the property with the most Aspen trees always made me feel a little more confident about my situation.

Posted By BadgerBoilerMN on 09 Jul 2013 07:10 AM
Here are a few lessons.

Don't build in high, dry, wild forested areas.

That would mean that you wouldn't be able to build in the entire western portion of the USA. Not very reasonable.

I believe a better approach is what I have listed and what has been stated by the numerous agencies that have studied and reported on how to build fire resistant structures.

We lost our home Sept. 4th, 2011 to a wildfire. It had a metal roof and 100% concrete siding and trim. And there was plenty of open space around the house. If I had stayed with the house I probably could have saved it, but in the middle of a drought, my well had limited capacity. Being home alone, I left with pets, critical documents and the RV. From other accounts, embers blew into the downwind, open carport, found sufficient fuel and slowly burned until it penetrated the garage and then the house. Bottom line, even a wood deck, wood fence or other small fuel source can be catastrophic. We rebuilt in 7 months and were blessed with significant help. I was the GC, architect and primary worker. Site cleanup took two weeks, then house plans and steel building plans, slab poured 6 weeks after the fire, another 6 weeks to erect the welded frame building with doors and windows. Inside framing/doors, rough electrical and wall insulation was finished in one week thru the help of 8 retired volunteer buddies from across the state. Then we were able to move the RV inside the new garage for Christmas. Four weeks for plumbing rough-in, HVAC, order kitchen cabinets, stain and varnish vanities. One week for the drywall sub and two weeks for us to paint walls/ceilings. Finally 5 weeks for the subs to install/paint the kitchen cabinets plus granite counter tops while I installed vanities, trim, toilets, door/cabinet hardware, closet shelves and finish electrical. Slab is colored concrete, exterior walls are 10" thick R30, HVAC is a 2 ton 16 SEER two stage heat pump. There is no exterior wood. I would like to install operable steel shutters for the windows, but there are no combustibles adjacent to the structure. So, some people do learn from a wildfire, but I believe many homeowners with limited construction knowledge, full-time jobs and restrictions from lenders, insurance companies, even building codes are forced again into conventional homes.

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Posted By dayle1 on 15 Jul 2013 08:30 PM
We lost our home Sept. 4th, 2011 to a wildfire. It had a metal roof and 100% concrete siding and trim. And there was plenty of open space around the house. If I had stayed with the house I probably could have saved it, but in the middle of a drought, my well had limited capacity. Being home alone, I left with pets, critical documents and the RV. From other accounts, embers blew into the downwind, open carport, found sufficient fuel and slowly burned until it penetrated the garage and then the house. Bottom line, even a wood deck, wood fence or other small fuel source can be catastrophic. We rebuilt in 7 months and were blessed with significant help. I was the GC, architect and primary worker. Site cleanup took two weeks, then house plans and steel building plans, slab poured 6 weeks after the fire, another 6 weeks to erect the welded frame building with doors and windows. Inside framing/doors, rough electrical and wall insulation was finished in one week thru the help of 8 retired volunteer buddies from across the state. Then we were able to move the RV inside the new garage for Christmas. Four weeks for plumbing rough-in, HVAC, order kitchen cabinets, stain and varnish vanities. One week for the drywall sub and two weeks for us to paint walls/ceilings. Finally 5 weeks for the subs to install/paint the kitchen cabinets plus granite counter tops while I installed vanities, trim, toilets, door/cabinet hardware, closet shelves and finish electrical. Slab is colored concrete, exterior walls are 10" thick R30, HVAC is a 2 ton 16 SEER two stage heat pump. There is no exterior wood. I would like to install operable steel shutters for the windows, but there are no combustibles adjacent to the structure. So, some people do learn from a wildfire, but I believe many homeowners with limited construction knowledge, full-time jobs and restrictions from lenders, insurance companies, even building codes are forced again into conventional homes.

I am sorry for your loss but at the same time I am happy you rebuilt. As you mentioned, wood decks, wood fences, or any fuel source near the home that can combust from embers, needs to be addressed.

Was your original home wood framed? Did you have any soffit, ridge or attic vents that embers could have accessed?

Posted By Lbear on 16 Jul 2013 01:00 AM

I am sorry for your loss but at the same time I am happy you rebuilt. As you mentioned, wood decks, wood fences, or any fuel source near the home that can combust from embers, needs to be addressed.

Was your original home wood framed? Did you have any soffit, ridge or attic vents that embers could have accessed?

2x6 stud walls. While I did have soffit vents, they were parallel to the wind direction and the wind was so strong that heat damage to the tree leaves was limited to the lower 10ft. Fire spread mainly occurred on the lee side of objects where embers came to rest. Most trees had enough moisture and bark that they did not burn, just blackened on the lee side. But any dry wood on the lee side of a building and it was gone. We even had a stand alone covered patio, one 4x4 post burned completely and a few feet of the 2x6 roof truss, nothing else, structure left standing on 7 remaining posts.