TLR  ECO  NOTEBOOK

 

Jan. 2006                                Jim & Priscilla Stanley                                            Chapter XXIX

 

 

WILDFIRE  PREPAREDNESS

 

With the unusually dry conditions and many brush fires burning around the state, it seemed like some discussion of wildfires and home safety might be in order, even though this might not seem like an ecology topic.  Since Priscilla has spent many hours doing Firewise visits with members of the Tierra Linda Volunteer Fire Department and Jan Fulkerson of the Texas Forest Service Urban Wildland Interface group, we decided to collaborate on this topic.  We just received information from the Texas Forest Service that on a 7 step drought-based wildland fire risk scale, our area is currently rated in the 6^th category, where 7 is the highest possible risk.

 

Jan Fulkerson of the Texas Forest Service, who performs our voluntary Firewise Property Assessments in Tierra Linda, provided the following sobering statistics on the current wildland fire situation in Texas (as of last week):

            Since the first of December:

            Over 514,000 acres have burned in Texas

            We have lost 354 homes

            Of the state’s 252 Counties - 210 counties have Outdoor Burn Bans, and 64 of those counties have   a Local Disaster Declaration

Please read on to see if there are any actions that you might want to take to make your home better prepared to withstand a wildland fire.

 

Before we can discuss how to protect your home from wildfires, we need to reflect a little on the nature of how fires are started in general.  Most of us have some experience lighting campfires, so we know that you don’t make a pile of 6” logs and hold a match under them.  While the temperature of the flame from the match is hot enough to ignite the logs, the match doesn’t burn long enough (before it burns your fingers) to get the temperature of the logs high enough to ignite.  But we can light a pile of dry twigs with a match, and with the fire from the twigs we can get small limbs to burn, and a pile of burning limbs will then light the logs.

 

In the case of your house and wildfires, your house is the logs and burning grass is the match flame.  A dormant, short, dry Bermuda grass lawn burning against a wooden-sided house is not likely to ignite the house, because the amount of fuel in the grass is usually insufficient to burn long enough to catch the siding on fire.  What is missing are the twigs and the limbs of our campfire.  But what if a grass fire comes across the pasture, ignites your Bermuda grass, and the Bermuda is growing up to and a little under your wooden deck, and under the deck is a lot of scrap lumber and trash you have been meaning to clean up, some small limbs you keep for starting fires in your fireplace, and a small pile of firewood?  Then the grass can ignite the trash and small pieces of lumber and limbs, which then catch the firewood, which then burns through the wooden deck, and the subsequent fire burns a hole in the ceiling over the deck and into your attic.  This is just one example of how a grass fire can become a house fire. 

 

When ranchers conduct prescribed burns of their pastures to improve the grass and control small cedars, they do so under strictly prescribed conditions of wind, humidity and moisture content of the cedar.  These burns will kill, but may not burn, small cedars.  The fire may in fact go out when it comes to a large cedar brake.  However, under the drier, windier conditions of some wildfires, burning grass can ignite cedars, creating a brush fire, which under even drier and windier conditions can become a crown fire in which the fire leaps from tree top to tree top with large burning embers being carried by the wind.  The Shepherd-Rees fire in September 2000 in Kerrville, which burned for seven days, was an example of a crown fire.

 

Obviously, as the intensity of the fire increases, the conditions necessary to prevent your house from being involved become more demanding, but the principles are still the same as with the match and the logs.  You want to prevent any flame from contacting any part of your house for long enough to cause ignition.  And you do this in two ways:  (1) make sure there is no potential fuel source large enough to sustain a flame close enough to your home to cause it to ignite, and (2) make your home as fire resistant as possible.

 

Cedar trees, because of their high leaf surface area and high resin content burn much more intensely than deciduous trees and live oaks and are thus more likely to catch adjacent structures.  In general, the closer a fuel source is to the house, the larger it is, and the more likely that it would be ignited by the wildfire, the greater the potential hazard.  Also, since most of the heat from a fire rises, it is more likely to catch parts of adjacent structures that are above the flame, such as raised decks or roof overhangs.  Trees with limbs near the ground are much more likely to become involved than similar trees with limbs trimmed up to 5 or 6 feet.  Deciduous trees and live oaks are unlikely to catch fire except under the most extreme fire conditions.  Thus, in Firewise property assessments, Jan Fulkerson has no problem with these trees near a home.  She does recommend that the branches be kept 3 to 5 feet from the home, primarily to avoid damage to the roof or walls, and that the branches not be allowed to grow within 10 ft of any chimney, where they could potentially catch fire.

 

Maintaining landscape plants near your home at a moderate size, and keeping them watered greatly reduces the fire danger.  If shrubs growing up in front of windows caught fire, they could cause the glass to break, thus allowing the fire to spread into the home.  Pampas grass represents a high fire risk since it is a large plant that ignites readily and burns with a very hot flame.  If tall pampas grass under the eaves of a home catches fire, it becomes a fire-ladder that can burn through the soffit into the attic causing a serious house fire.  Coniferous shrubs, rosemary bushes, yaupon holly and agarita also burn with a hot fire.  If you grow them near your home, you can minimize the risk by keeping them moderate sized, and away from windows.  Jan Fulkerson doesn’t recommend that residents remove small landscape plants from around the house, or even trimmed up cedar trees that are several feet from the home.

 

Firebreaks, such as driveways, stone walkways, rock walls, and concrete or stone patios, provide helpful barriers between the fire and your house, and the larger they are the better.  Stone siding is obviously less flammable than wood or vinyl, and metal roofing and composition shingles are much safer than cedar shake roofing.  Double-pane glass is safer than single pane.  Reducing the amount of flammable material stored on porches, decks, or against the house is very important.

 

In assessing the danger around your house, it is important to think about what is called the “fire ladder”.  The idea is to think about what will happen if a grass fire in the pasture comes into your yard, how could the fire be conducted up to and against or under any part of your home?  For example, if a grass fire came under that tree, would it catch the adjacent tree, and if so would the fire burn under the eaves, or could it catch something else that is under a large picture window?  By looking at everything in that manner, taking into account the flammability of the material, the amount of it, and how your house is constructed, you should be able to identify what, if anything, you could do make it more likely that your house will survive a wildfire. 

 

It should be noted that homes on steep slopes or on hilltops just above steep slopes can potentially experience much more intense fires due to the heat of the fire burning uphill.

 

Home     Meetings and Event   Projects   Advanced Training   About    TX Hill Country   Links   News and Archives

 

Some recommendations from the Tierra Linda Firewise program are as follows:

 

Grass should be mowed or weed-eaten at least 30 ft from a home, when the grass becomes dormant, dry and brown.

 

Individual cedars within about 30 feet of a home should either be removed or have the lower limbs pruned up to about 4 or 5 feet.  Dense cedar thickets represent a bigger hazard than individual trees, so a greater distance between them and your house may be warranted.  Also, if the driveway to your home is lined with cedars, this represents a hazard to fire equipment and volunteers, so they may not be able to get to your home during a wildland fire. Some cedar brakes are desirable on your property as shelter for wildlife or for privacy, but these should not be near your home.

 

Keep leaves from collecting in your gutters, or in wind-blown piles on your porch, deck etc.  These leaves could be ignited by burning embers from a fire or from a grass fire. 

 

Your main woodpile should be at least 30 ft from anything you don’t want to burn (including your home), and not downhill from your home.  Smaller amounts for use can be stored closer to your home.

 

If a wildland fire is in the area or if you are traveling, bring inside readily combustible material near your home, such as wicker or plastic porch furniture, upholstered cushions, fiber doormats etc. to prevent firebrands from igniting these items.  Homes can survive a wildland fire, only to succumb afterwards to spot fires started by flaming debris.

 

If you are putting in a water storage tank, install a fire connection to enable the Fire Department to draw water from your tank.  Contact Fire Chief Mike Lannan for specifications for the fire connection.

 

If you are building or remodeling your home, consider using Hardiplank, a non-combustible fiber and cement replacement for wood and shingles.  If you are building or replacing a wooden deck, the use of fire-resistant synthetic wood-like products will make your home more fire-resistant.  An added bonus is reduced maintenance on these products, which can offset the increased cost.

 

Installing 1/8 inch mesh metal screening under wooden decks, porches and sheds prevents leaves and other combustible material from accumulating there, and keeps out burning embers during a wildland fire.  This screening can also protect the roof peak vents and soffit vents on your home from burning embers.

 

Each step you take toward wildland fire preparedness makes your home better able to survive a wildfire.  This is an area where proactive efforts can pay enormous dividends.