Can You Put a Fire Pit on Composite Decking?

Putting a fire pit on your composite deck seems like it would be okay, right? After all, most composite decking is a mixture of wood fiber or byproducts and some type of plastic. Having the fire pit on your deck means it’s conveniently close, level, and easy to keep an eye on. You may even have a nice table or bench seating nearby to enjoy the warm flames. All of this sounds pretty good, but only if having a fire pit on composite decking is possible in the first place.

Putting a fire pit on composite decking is completely safe as long as it’s not positioned too close to the home or any other surrounding structures. A heat resistant mat or stand should also be placed between the fire pit and the deck to help prevent damage that could occur due to the heat of the fire pit itself.

Read on to discover exactly what you need to do to enjoy a fire pit on your composite deck.

Not All Composite Decking is Created Equal

It’s important to note that there is no such thing as fireproof composite decking. Whether it’s made out of a mixture of wood byproducts and plastic (like PVC), or it doesn’t have any wood products inside at all, it’s still not going to be 100% fireproof. 

There are, however, different levels of fire-resistant composite decking. If you do plan on putting a fire pit on your composite decking, it’s a good idea to get material that’s highly rated for fire resistance. More on that below. 

If you’re looking for a completely fireproof material, stone or concrete is your best bet.

Fire Resistance Ratings

Without getting into a technical discussion about the methods used to test flame resistance, let’s get a broad overview of which rating is best for our purposes. 

• Class A
  • Class A materials have a score between 0 and 25 in regards to flame spreading and is considered the most flame retardant. If you’re planning on having a fire pit on your deck, a Class A rating is ideal. 
• Class B
  • Rated between 26 and 75, Class B materials are considered moderately fire resistant. 
• Class C
  • Rated between 76 and 200, Class C materials will not hold up well under anything but light flame exposure. 

Class A Decking Materials

• AmeraDeck manufactures decking made out of wood, plastics, and fiber. People who have it like it well because it’s safe, doesn’t scratch or stain easily, and lasts a long time. However, it doesn’t seem that AmeraDeck is available everywhere. 

• Trex boards themselves are rated Class B or Class C, but the company does make a Class A rated substructure product. That is only useful if you are building the deck from scratch, but it is worth asking about. 

• TimberTech makes Class A rated decking material that’s growing in popularity. Their AZEK Vintage Collection is fully synthetic, meaning there’s no wood fibers or byproducts that could possibly catch fire. 

Code Requirements

It’s a good idea (especially if you live in California) to check out the local requirements for building materials. Places that experience terrible wildfires on a regular basis are getting serious about flame retardant materials used in construction. In some cases, it can be a matter of life and death. Even if you’re not in a fire-prone area, you still may want to check local laws regarding both building materials and the use of backyard fire pits. 

How Hot Does a Fire Pit Actually Get?

The temperatures involved are the reason a heat barrier matters. Wood starts burning at around 570 degrees Fahrenheit, climbs past 1,100 degrees once it is going, and the coals left behind can sit near 2,000 degrees, according to Sciencing. Most of that goes straight up. What reaches your deck is the radiant heat coming off the bottom and sides of the pit, and in a metal pit that lands somewhere in the 200 to 400 degree range depending on how close it sits.

Now hold those numbers against what your deck can take:

• The plastics in composite decking soften at around 175 degrees.
• They melt somewhere between 250 and 350 degrees.
• Wood decking can start to warp in that same 250 to 350 degree range.

A pit sitting flat on composite does not have to set anything alight to wreck the boards, and a melted or warped patch does not come back. It is also why a wood fire keeps you warmer than propane and is harder on your deck at the same time, since it is the same heat in both cases.

A crew at TimberTown ran an open-flame test on cedar, Ipe, a composite board, and AZEK, holding each over a flame for 15 to 20 seconds. The AZEK came out looking rough but never caught. The other three did, to varying degrees. Even the best-rated board is fire resistant, not fireproof.

Consider Type and Style of the Fire Pit

Once you’ve decided on the material you want, it’s time to look at the kind of fire pit you want to use. Whether you already have one or you’re in the market, we’ll help you determine if it’s right for use on your composite decking. No matter the type, you’ll want to get one with reasonable clearance (6 to 12-inches) to protect your deck from the heat. 

Wood or Propane

The two main types of portable fire pits are wood and gas. Each has its advantages and drawbacks that may vary depending on what you’re envisioning for your deck. 

Wood

Wood-burning fire pits are great for a couple of reasons:

• They crackle and pop.
• They smell like a traditional chimney fire or campfire.
• Feeding the fire can be a relaxing and fun activity.
• If you live in a wooded area, they can help you get rid of dead wood from your property. 

Many of the things that make wood fire pits great also contribute to their drawbacks:

• When they crackle and pop they can send sparks or embers out, which can cause unsightly marks on even Class A decking. These embers can also cause a fire under the right circumstances.
• Smoke may irritate family members or neighbors. 
• Many places have regulations against wood burning. 
• Some laws require that your wood fire pit be at least 25 feet from your house.
• It can be a chore to constantly stock and replenish firewood.

If you get a wood-burning fire pit, it’s a good idea to purchase one with a spark screen or one that’s compatible with a third-party screen. It adds protection against popping sparks and embers while still allowing you to watch the flames and feel their warmth. 

Propane

Portable propane fire pits are a popular option for several reasons:

• No wood to mess with; easy to light and control the flame. 
• They give off heat and light just like a wood fire— without the risk of embers flying out.
• Generally easy to set up and some models are relatively inexpensive. 
• Most models have a safety mechanism that puts out the flames if the unit tips over.
• Some areas consider propane fire pits ‘fire features,’ which are allowed closer to flammable structures than wood-burning pits. 

Propane Fire Pit Drawbacks:

• They generally don’t emit as much heat as wood-burning pits.
• They lack the smell, sound, and activity associated with wood-burning pits. 
• The cost of propane can be prohibitive if you use the fire pit enough. 

Height From The Deck

When deciding on a fire pit, consider how high the actual heat source will be off of the deck. You generally want to avoid low fire pits because they can cause cosmetic damage to even the best composite materials. Most fire pits available have legs or a surrounding structure to keep the heat source well off the ground, but not all of them. 

Keep this in mind when you decide on a pit. The actual height you need will vary depending on the fuel source you’ll use and what kind of protection you choose for your deck. 

Protect Your Deck

There are a lot of different options for heat barriers to put on your deck. Some are better than others, so it pays to look at reviews and specs. We have a couple of suggestions below, but you’ll want to verify that they’ll work for your particular needs. 

Pavers

For a thick layer of protection, you can lay down pavers or bricks on your deck. Simply make the platform large enough so you can put your fire pit on top, and you’ll be good to go. You may even have spare pavers stashed in your yard or shed. 

Just make sure you give a little room for error as far as the base of the fire pit is concerned. If someone accidentally bumps the pit, you don’t want the pit to fall off the platform and dump coals on your deck or your guests. 

Fire Protection Mats

There are several options on the market, but we’ve picked one that seems to be the best all-around. Many of these mats are around the same size, so if you need a larger one you may have a tough time finding one of quality. 

Newtex 36” FirePad Deck Protector – The manufacturer suggests at least 6-inches of space between the bottom of the fire pit and the mat. If your fire pit is large, this 36” mat may not be enough to stop all radiant heat from warping or damaging the area.

Fire Protection Stand

Unlike the mats, there are only a few of these stands on the market. The problem is that they are pretty small. Depending on the size of your fire pit, there may be no room for error, meaning if someone bumps the pit, it could topple off the stand. Still, for smaller pits, they’re probably the best you can get for deck protection. 

Northland 26”x26” Deck Defender and Grass Guard – This stand has feet of its own, which gives you even more space between your deck and the heat. Made in the USA, no assembly required, and it comes with a 2-year warranty. 

Mind the Wood You Burn

If you go with a wood-burning pit, what you put in it changes how much of it ends up on your deck. Some woods snap and throw embers, and those embers leave black marks on composite that do not brush off. Heavy smoke and heavy sparking tend to travel together, so a pit that smokes constantly is usually a sign you are burning the wrong stuff.

Woods that tend to spark and smoke:

• Fir
• Spruce
• Pine
• Locust
• Hickory

Woods that generally burn quieter:

• Oak
• Maple
• Elm
• Birch
• Black cherry
• Beech

A few habits are worth having in place before you light the fire, wherever the pit is sitting:

• Keep water, sand, or an extinguisher within arm’s reach.
• Check the wind first. A gust can carry embers to your house, a neighbor’s, or a patch of dead grass.
• Never leave the fire unattended, and put it fully out before you go inside.
• If you are the one responsible for the fire, go easy on the drinks.
• Go over the rules with kids before the fire is lit, not after.

Placement of Your Fire Pit

As we mentioned above, it’s a good idea to check your local laws regarding fire pit placement. 

• As a general rule of thumb, you’ll want to put your pit at least 10 to 15 feet away from any structures— including your home. Some areas have laws requiring a distance of 25 feet from your home. 
• Make sure your pit isn’t under awnings, overhangs, or branches. 
• Allow for seating around the fire pit. For safety sake, you want to keep seating about 4 to 5 feet away from the pit. 
• Place the pit where you can easily see it. Line of sight is important, even though it should never be left unattended.

As you can see, it’s definitely possible to put a fire pit on a composite deck. With a little bit of research and preparation, you can enjoy the warmth and relaxation of a fire on your own back porch without damaging your deck or engaging in risky behavior.

Have fun!