Understanding the Importance of Fire Ratings

When a homeowner is deciding on or a contractor is building an outdoor deck , one of the first things that comes to mind in protecting the integrity of the deck is to apply a quality coating to waterproof the structure. However, what is often overlooked is the importance of fire ratings for the coating product selected. Why does it matter? What are the differences between options?

Why It Matters

Protection is the key reason fire ratings matter when it comes to waterproofing a deck. Rain and sun are not the only elements a deck needs protection from. If a deck becomes weakened through moisture or fades, dries and cracks from sun damage the loss is the value of the deck itself. However, if an outdoor barbecue leads to a fire on the deck, a fire could cause not only the loss of the deck, but also the loss of the home. By choosing a waterproof coating that has at least a one hour fire rating, homeowners can save their homes from a deck fire.

Ratings Differences

For the average deck owner, understanding the differences between fire ratings can seem like reading a foreign language. The ratings represent the standard of tests that have been used to determine how resistant a product is to fire penetration. Pli-Dek coating systems have proven effectiveness with regard to fire safety standards with ratings of ASTM E108 and ASTM E119.


This rating informs the consumer that testing has been performed to assure that Pli-Dek coating meets the following fire resistant standards:

  • When a deck treated with Pli-Deck waterproof coating was exposed to a 1400 degree Fahrenheit flame for ten minutes, an area of less than 10 inches was affected by heat.
  • When a Pli-Dek treated deck was exposed to (15) two-minute cycles of 1400 degree Fahrenheit flame there was no eruption of flame or cinders produced.
  • When 6″ square burning brands were applied for four minutes to joints of a Pli-Dek treated deck, no stress was produced.


If a product contains the claim that it has a one hour fire rating, it has passed the standard testing to qualify for an ASTM E119 rating. The Pli-Dek coating system meets this standard.

  • When a deck treated with Pli-Dek had burners, producing one million BTUs, applied to the deck’s surface for sixty minutes, producing a minimum temperature of 1400 degrees Fahrenheit, the deck’s surface did not rise above 250 degrees Fahrenheit.

Going Without Fire Resistance

The primary reason homeowners install a deck is to enjoy outdoor activities. Such activities usually include entertaining friends and family with an outdoor barbecue. The dangers of grilling on a deck that is not treated with a coating that is fire resistant as well as waterproof can lead to tragedy and loss.

Wind and sparks are the perfect recipe for disaster. Grills produce sparks and wind can carry those sparks to any number of areas on a wooden deck that can lead to a fire. It is also common to construct a deck where the comfort of shade trees can be enjoyed. An awning over an entry door into the home may also overhang a portion of a deck. All of these shade producing items are flammable. Sparks can quickly turn into a fire that rages out of control and destroys a home.

Grills, themselves, can be the danger. Leaky propane tanks can create fire and explosion risks. Any nearby wooden deck surface, even railings, become a potential ignition source. The underside of a charcoal grill is also a danger zone. An ember or coal can drop and slowly burn unnoticed.

For more information on how you can make your deck fire resistant with a Pli-Dek waterproof coating, please contact us. Our coatings experts can help you determine if a Pli-Dek coating is the perfect solution for improving your deck and preserving your home.