Fire Fence Fire Retardant
How it Works &
Frequently Asked Questions about Fire Fence
What is Fire Fence?
Fire FenceTM is a fire retardant to protect residential properties from forest fires.  It is an integral part of any comprehensive fire mitigation plan.

This video showcases how Fire FenceTM fire retardant stops fire.

How long does Fire Fence last?
Fire Fence solid lasts two years when stored in a dry place.  Once applied, Fire Fence lasts two-three months, or until a heavy rainfall which will dilute the effectiveness.  In the case of heavy rain, Fire Fence should be reapplied. 

Because Fire Fence is a preventative measure, Fire Fence is great for vacation properties which may not be occupied during a wildfire threat. It also provides additional security when applied to ranches or properties at the beginning of fire season.

What are the effects on animals and vegetation?

There are no known adverse effects when wildlife, domestic or farm animals eat small amounts of retardant coated foliage.  Consult a veterinarian if you suspect your pet has ingested large amounts of retardant.  Studies conducted by the federal government indicate the active ingredients show no or low acute toxicity to small wildlife (ie: birds, rodents and worms).  Studies on aquatic organisms show similar no or low order toxicity when subjected to runoff, however if applied in significant quantities directly into water bodies, the materials can be toxic;  Therefore, Fire FenceTM should never be applied into water bodies.

Foliage may turn brown and look weak when Fire FenceTM is applied, but after rain or heavy watering foliage will grow back stronger and greener due to the fertilizing and nutrient effects of the nitrogen and phosphorous



Slurry is shown above dropping from an airplane.  Fire FenceTM is essentially slurry for residential use.  We use the same primary ingredient used by the USDA Forest Service to stop major wildfires.
How does Fire Fence retard fire spread?
Fire normally spreads by drying out fuels as it advances and releases gases which ignite.  The active ingredients in Fire FenceTM
react with cellulosic fuel sources such as grass, pine needles, wood, shurbs, etc. to render them non-combustible by changing the fuel surface into carbon and releasing water which absorbs heat and cools the fire.  This char insulates and retards wildfire flame spread.  More information on Ammonium polyphosphate, the active ingredient in Fire Fence, is described here from

"As a fire retardant, ammonium polyphosphates decompose to form ammonia and phosphoric acid.  The phosphoric acid acts as an acid catalyst in the dehydration of carbon-based poly-alcohols, such as cellulose in wood.  The phosphoric acid reacts with alcohol groups to form heat-unstable phosphate esters.  The esters decompose to release carbon dioxide and regenerate the phosphoric acid catalyst.  The release of non-flammable carbon dioxide helps to dilute the air of oxygen and flammable decomposition products of the material that is burning. The resultant carbonaceous char is less-flammable than before."

How is Fire Fence applied?
Fire Fence
is a water-soluble, colorless fire retardant easily applied with any backpack sprayer, garden or agricultural sprayer.  Fire Fence is best applied at the beginning of fire season to dry grasses, shrubs, brush, slash piles, wood or other cellulose materials around your home as part of a comprehensive fire mitigation plan.  Fire Fence is a pre-treatment and is not intended to fight an active fire.  Click here for detailed application instructions.

Fire Fence is available in either 100% solid form or a ready-to-spray solution.  Solid powder should be dissolved in water before use.  1½ cups powder to 1 gallon water (1.5 lbs/gallon of water), or 7½ cups powder to 5 gallons of water will make a ready to spray solution.

Recommended fire mitigation strategies
Fire Fence is most effective when used as part of a comprehensive fire mitigation plan.  Fire Mitigation strategies include examples shown in yellow on the figure to the left including thin trees, clean roof & gutters, cut grass, stack firewood away from home and prune branches at least six feet up from the ground.  Then, clear as much brush and deadwood as possible.  Saturate grasses, brush, wood and/or other vegetation thoroughly and liberally with Fire Fence.  Applying smaller than recommended amount, over diluting mixture with water or incomplete area spraying will reduce the effectiveness of Fire Fence.


How much Fire Fence do I need to protect my property?
Each package of Fire Fence solid makes approximately 5 gallons, which covers 500-800 feet2.   A collegiate or NBA basketball court is 4700 feet2, so you would need 7 packages of Fire Fence to cover the area of the basketball court:  4700 (size of basketball court) divided by 650 (average area covered by one package of Fire Fence) = 7.2 packages.  Keep in mind, however, you likely aren't covering an area as wide as a basketball court.  Instead, you should treat the perimeter of your property, to stop fire from encroaching towards your house, and any large brush/wood piles in your yard.
  1. Measure the perimeter of your property (or area to be protected) in feet.  (Simply walk the perimeter of your property.  One large step is approximately one yard which equals three feet.)
  2. Determine the width of spray necessary given the burnable fuel/vegetation of your property using chart below.  In general, spray 2X as wide as fuel is high.
  3. Multiply step 1 x step 2 to estimate quantity needed.  Five gallons of Fire Fence ready to spray solution will cover approximately 500-800 feet2.  Use the burnable fuel/vegetation area type to determine if more of less Fire Fence is needed.*
*This calculation is meant as an estimate only.  Mountain property acres are not all shaped equally or in perfect squares, therefore area coverage is not exact.  One package of 100% solid Fire Fence dissolved in water makes slightly more than the five-gallon ready to spray solution.

Burnable fuel Fuel height Spray width   Tips for increased protection
Grass  6-12  inches 12-24 inches Apply Liberally Cut grass short before application.
Brush (small bushes & trees) 2-4 feet 4-8 feet Apply Liberally Be sure to reach thatch under bushes & trees.
Forest needles, leaves, twigs, etc.   8-16 feet Saturate Rake pine needles from under trees
Example of Calculation to determine amount of Fire Fence needed:
  1. Jane walked the perimeter of the area she wished to protect with Fire Fence.  It was 30 large steps (90 feet).
  2. The area walked had small trees, and she wanted to protect the tree base which was covered with pine needles. (Spray 8-16 feet wide.)
  3. Multiple step 1 X step 2:  90 feet X 16 feet = 1440 ft2
  4. Since each 7-lb solid Fire Fence package covers approximately 500-800 ft, Jane needs two-three 7-lb solid Fire Fence packages to cover the area (1440 ft2).  Given the spray area's burnable fuel is comprised of pine needles which recommends wider spray width and saturation coverage, err on the higher end of quantity needed.

Is Fire Fence guaranteed?
Consistent with other fire mitigation efforts, there is no guarantee Fire Fencewill immediately stop fire.  Fire Fence ingredients, however, have proven successful and remain the most common resource by the USDA Forest Service in fighting major forest fires.  Slurry, red fire retardant often seen dropped from airplanes, shares its primary ingredient with Fire Fence, and has been used by the USDA Forest Service over the past 30 years.

What is the Fire Fence return policy?
Our goal is complete satisfaction.  Unopened packages of 100% solid Fire Fence may be returned for a refund minus a $15 restocking fee.  The consumer pays return shipping fees.  To ensure the integrity of our product, Fire Fence ready-to-spray solution in non-returnable.

Why isn't Fire Fence red like they slurry I see dropped from airplanes?
Red dye is used in commercial slurry so the spotter can tell which areas the airplane has already sprayed when viewing from the air.  Fire Fence is clear in color so your property isn't stained and you can enjoy vegetation in its natural looking state.

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