Can You Have a Fire Pit on Trex or Composite Decking?

When spring hits and you start finding every excuse to spend time outside, a campfire is a great way to enjoy the chilly ends of warming days without getting too cold. If you have a deck and there’s enough space, a portable fire pit is a great way to stay warm without straying too far from your home.

If you’ve ever used a fire pit over grass, you’re familiar with the scorched area that is left behind after the fire’s gone out. If the heat is strong enough to destroy grass, just imagine how it would damage your deck! This might make you wonder, is it even safe to use a fire pit on a deck?

The answer is yes, but there are special precautions you must take.

You can use a fire pit on both trex and composite decking, but the decking requires a layer of protection between it and the heat from the fire pit. Never place a fire pit directly on any deck surface, wood or composite.

Let’s dive in and learn how to safely use a fire pit on our decks!

Does The Type of Decking Matter for Fire Pits?

A lot of people have opted for trex or composite decking for their patios instead of wood because it’s relatively the same price but lasts longer, is more durable, and requires very little maintenance. You also don’t have to paint or seal it.

Most importantly, composite decking can be more fire resistant. Manufacturers add in chemicals to the boards that make them harder to burn.

There are less flammable types of wood just as fire resistant as composite that you can use for decking, but they are very expensive.

Heat and Composite Decking

Most composite decking is fire-resistant and can withstand high heat. However, too much heat will soften the material and cause warping. This begins to happen at around 170 degrees.

After the composite boards have reached 250 degrees, the material will begin to melt. And since fire pits can radiate heat up to 400 degrees, a protective layer is crucial to maintain the integrity of the deck.

So, while it’s good to hear that it can handle heat better than wood can, it doesn’t mean you can place a fire pit straight on the deck without preparation. 

It is important to use a fire pit mat to prevent your decking from melting.

Can My Composite or Trex Deck Catch on Fire?

Regardless of the decking material, be it composite, treated, or untreated wood, it is all combustible and can catch on fire. 

Direct flames will scorch your deck, leaving behind ugly black stains that upset the appearance.

In the case of an uncontained fire, trex composite decking will burn through like wood does, so it’s classified as a Class C building material under the fire rating system.

Luckily, there are now three Class A composite decking types available. There’s AmeraDeck, which is a blend of wood and PVC, and AZEK and TimberTech, which are made with fully synthetic material. These are your safest bet against the heat of a fire.

Trex has special Fire Defense boards made with 50% wood and 50% polyurethane which makes it a slower process to burn, but it will still completely burn though after enough time has passed.

Regardless of its type, never place an open flame near composite decking. Take proper precautions with it like you would with regular wood and place a protective layer between it and any fire places.

Preparing Composite Decking for a Fire Pit

There are two things you should do to make sure your decking material is protected from the heat of a fire pit. 

First, consider installing or using a fire pit with a heating element further up off the ground. The greater the distance between the pit and the deck, the less hot the material will become. 

The general recommendation for above ground fire pits is to raise them at least 12-14 inches above the deck. 

Second, it’s extremely important to use a barrier between the pit and your deck before you light a fire. This is the best way to protect the composite decking from the heat.

Fire mats are specially made barriers usually made with fiberglass or fire-retardant film. They are the best and most popular option for fire pit protection.

Which is Best: Wood or Composite Decking?

There will always be people who opt for traditional wood decks because of their warm familiarity and added value to the home. They also like wood because it can be cheaper than composite if you’re using a certain type of lumber.

If you’re choosing wood for your deck, consider weather-resistant lumber like cedar or redwood to keep your deck boards from warping and aging faster from exposure to the elements. Always opt for treated wood as it will significantly increase the length of its lifespan and beauty. Regular wood decks only last up to 20 years while treated ones can last up to 50.

The downside to using wood decking materials is that, as opposed to composite decking, wood requires much more maintenance. Wooden decks require yearly cleanings and exfoliation and need to be sealed afterwards. Certain furniture needs to have a barrier between it and the deck to prevent scratching and other damage.

Another downside is that good-quality treated wood is very expensive. Composite decking is made up of recycled material, so the cost is lower than the higher-quality treated woods.

Besides being environmentally friendly, composite decking is also attractive because it’s low-maintenance, durable, and customizable. You can choose from a variety of colors, and advancements in design have made composite decking look more and more like real wood as time goes on.

Composite decking also won’t splinter, rot, or show stains or the effects of weather like wood does.

The downsides to using composite decking are that they don’t look as natural as wood, they show signs of aging, and they’re capable of molding and mildewing like wood is.

What is Composite Decking Made Of?

Composite decking is special and goes above and beyond the quality of wood. It’s also called wood polymer, recycled decking, and synthetic decking and it’s made from wood fibers from recycled material and plastic. 

The recycled material can be anything from wood chips to sawdust and they use all types of plastic, whether newly created or recycled.

The two main types of composite decking are capped and uncapped. Early versions of trex decking materials were uncapped, meaning their cores didn’t have a protective layer shielding it from the elements.

Uncapped composite decking is subject to molding, cracking, staining, crumbling, and fungal growths. 

Over time, manufacturers began producing capped composite decking material that only protected the top part of the decking boards. The underside and grooves were left exposed and caused the boards to warp and crack.

Finally, fully capped composite decking material was developed and every part (except the ends) of the boards were capped with a protective layer.

It’s important to note that the cores of completely capped composite decking boards are still susceptible to water damage, so it’s recommended to put end caps on or apply a sealant after installation. 

Tips for Fire Pits on Composite Decks

To keep it safe, consider the following tips for using a fire pit on a composite deck.

  1. Check local regulations

Before you use a fire pit anywhere, always check the local fire regulations for your area. Your deck might not even be big enough for you to legally put a fire pit there. As for the other codes, they’ll give you a guideline for placement and handling of the pit in more detail.

  1. Have easy access to a fire extinguisher

This one goes without saying and applies to all fires (except electrical ones). Keep a fire extinguisher or water source nearby so you can extinguish any unruly flames.

  1. Stay alert

Never leave an active fire pit unattended! This could have disastrous consequences to more than just your deck. Keeping an eye on the flames and embers gives you chance to prevent things from getting out of hand.

  1. Avoid flammable liquid

Don’t use anything like fire starter or gasoline in a fire pit on a deck. This could turn dangerous quickly by turning a reasonably-sized flame into an uncontrolled and raging fire.

  1. Avoid soft or wet wood

Softer woods like cedar and pine are great for burning and a favorite for fire pits, but they are more likely to crack and pop, sending off embers in all directions. The same goes for wood that hasn’t completely dried yet. These embers have the potential of damaging the decking. Opt for fully dry, denser firewood like beech or maple.

Final Thoughts

A cozy, firelit evening on your trex or composite deck is not only possible, it’s safe if you use the right materials and make the right preparations.

Trex Fire Defense Boards and composite decking rated Class A are the best options for building your deck because they can withstand higher heat than regular trex and other Class C-rated decking.

When the deck is built, invest in a high-quality fire pit that stand at least a foot away from the ground.

Laying a protective fire mat between the pit and the deck is the most important step, and is the key to preserving your composite deck from heat damage. You should use it even if you have Class A-rated decking.

Lastly, keep up with your deck and your fire pit! Unkempt surfaces will build up ash and dirt and speed up the aging process of both the pit and the deck. Regular cleaning and maintenance will ensure a long lifespan of your deck.

Enjoy the warms nights ahead!

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