If you’re planning to build a fire pit on your wooden deck, you may be wondering whether it’s even possible. After all, the temperatures of a fire pit can rival those of a bonfire, and any reasonable person would realize that those temperatures and a wood deck probably don’t mix.
It is possible to put a fire pit on a wood deck if it is done with safety in mind. Location of the fire pit, proximity to flammable objects, base protection, and safety guards all help to make fire pits on a wood deck safer. When choosing a fire pit for a wood deck, gas fire pits are also a safer choice than wood-burning fire pits because they put off less heat and fewer sparks.
Putting a fire pit on a wood deck can be dangerous—even deadly—if it isn’t done correctly. Read on to find out what you need to know before building a fire pit on your deck and how you can do so safely.
Is It Safe to Build a Fire Pit on a Wood Deck?
It is safe to build a fire pit on a wood deck, but you’ll want to do a few thing to make sure it’s safe. It isn’t just a matter of putting fire on top of a wooden structure—even if there isn’t direct contact between the fire pit and the deck, the heat and sparks that fly can still cause a dangerous fire.
The main things that make a fire pit safe to build on a wood deck are the following:
- Clearance: Making sure that the fire pit is not near flammable objects or has them in proximity to it is vital to preventing a fire on the deck. Keep in mind that flammable objects do not have to touch a fire pit directly to combust from the heat being generated. That’s why we also recommend using a fire pit ring. That’s why we also recommend using a fire pit ring.
- Base protection: A fire pit cannot be placed directly on a wood deck, as this will eventually cause heat damage to the decking and can also spark a fire.
Instead, a heat-resistant base should be placed between the fire pit and the deck to absorb the radiant heat coming through the bottom of the pit and preventing it from combusting or burning the wood decking.
- Weight support: You must know how much weight your deck can support when deciding to install a fire pit, and structural supports should be put into place to ensure that the weight of the pit will not cause the deck to give way.
This is especially important if you expect large groups of people to gather around the fire pit, increasing the weight on the deck.
- Safety accessories: It’s a good idea to have certain safety accessories for your fire pit available to keep the risks at a minimum, such as a fire extinguisher and spark guards. These can help reduce the chance that a stray ember might catch the deck on fire and can help you put the fire out quickly in a worst-case scenario.
Ignoring any of these factors when putting a fire pit on a wood deck can lead to an uncontrolled fire that can soon envelop the rest of the house since decks are often directly attached to residential spaces. Therefore, each of these factors needs to be considered on its own.
Fire Pits and Radiant Heat
One significant danger of fire pits on a wood deck is radiant heat. While there may be plenty of clearance between the fire pit and other flammable items on the deck, the radiant heat given off by fire pits—especially wood-burning fire pits—can catch items on fire even if they aren’t nearby.
Another issue that fire pits present in a wood deck are sparks and embers (although this is more of an issue with wood-burning fire pits than gas fire pits). As they break down, logs in a wood-burning fire pit can not only put off a large amount of radiant heat, but they can also send up sparks and embers that can waft away from the fire and ignite nearby objects. The larger the fire pit and the larger the fire, the greater of a risk this situation is.
Radiant heat is a largely hidden danger in comparison to the flames and embers of the fire in a fire pit. Through the electromagnetic radiation that the fire gives off, nearby flammable objects such as dry leaves or pine needles can spontaneously combust without ever being touched by fire.
Radiant heat is also the culprit when fire pits burn through the bottom of a wood deck. Without proper insulation between the wood deck and the fire pit, the heat radiating through the bottom of the fire pit can scorch the wood of the deck and eventually combust if the fire pit is hot enough for an extended amount of time.
Fire Pits, Wood Decks, and Fire Codes
Before you even consider putting a fire pit on your wooden deck, you need to research the fire codes and housing ordinances in your area. In some cities or towns, it is illegal to install a fire pit on a wood deck under any circumstances due to the existing fire codes. Some of these areas are dry or prone to wildfire, so extra precautions are taken to prevent them.
Other housing ordinances may specify that you can have a fire pit on a wood deck, but it must be a gas pit rather than a wood-burning pit. Other fire codes may not prohibit the use of fire pits on decks at all. It all depends on where you live and how strict the fire safety regulations are there.
If you’re unsure of whether you can legally build a fire pit on your wood deck, check with your local housing ordinances to make sure before you get started. If you live in an HOA-controlled neighborhood, check the restrictions on exterior buildings and accessories on your property, as many HOAs forbid a fire pit even if the city ordinances allow it.
It is also a good idea to check if there are “burn bans” in your local area. In dry or fire-vulnerable regions, burn bans are periods during the year when controlled fires such as bonfires and pit fires are prohibited due to the threat of wildfire. If you get caught running a fire pit during a burn ban, depending on the regulations in your area, you may be subject to a fine or (at the very least) a scolding from the fire marshal.
Fire Pits and Clearance Restrictions
When building a fire pit on a wood deck, you need to consider the clearance around the fire pit.
(Source: This Old House) This is the area that needs to remain completely clear of any flammable objects that could ignite and spread the fire beyond the fire pit.
Some of these objects include the following:
- Awnings and sun umbrellas
- Patio furniture with flammable parts, such as seat cushions
- Firestarters or other accelerants used in grilling
Most of the time, the instruction manual on a fire pit will give very clear and specific restrictions for footage clearance around the edges of the fire pit and over it. These clearance restrictions should be strictly followed to install the fire pit correctly on a wood deck. The manufacturer of the fire pit should also provide these specifications online in many cases, so you can look at them before committing to a purchase.
This is an aspect of fire safety with fire pits and decks that you simply can’t cut corners with. If your deck isn’t large enough to ensure the proper clearance around and over the fire pit, your deck isn’t large enough for a fire pit.
Wood Decks and Fire Pit Weight
Something you might not consider when thinking about installing a fire pit on a wood deck is the weight involved. The weight of a fire pit can vary drastically from as low as 38 pounds up to 260 pounds, depending on the model the materials it is constructed out of. (Source: Ohio Flame)
Lighter fire pits should generally be chosen to be installed on top of decking unless there is significant structural support added underneath the fire pit to offset its weight. If you choose a heavier fire pit, there is a chance that the fire pit will collapse the wooden deck entirely. This is disastrously expensive at best and is potentially dangerous, especially if the deck collapses while there are a bunch of people on it.
To make sure that your wood deck can safely support the weight of a fire pit, you should do one of the following:
- Choose a lightweight fire pit that is designed for deck use
- Have a structural engineer assess your deck to see if supports are needed for the fire pit you want to install
It’s always best to overestimate the amount of weight a deck can support versus underestimating it, as you may not be able to anticipate the number of people the deck will support during future gatherings. Make sure that the deck is strong enough to be in no danger of collapse, even with a large group of people gathered around the fire pit. Don’t be afraid to call in an expert if you need to verify safety.
Fire Pits and Base Protection
One of the biggest concerns when it comes to a fire pit on a wood deck is the fire pit radiating heat through the bottom of the fire pit directly onto the wood of the deck. Not only can this cause heat damage and discoloration over several years, but without proper insulation, this heat can also cause the deck itself to catch on fire.
When you install a fire pit on a wood deck, you must put a non-combustible base between the fire pit and the wood of the deck. This is one of the most important things you can do when installing a fire pit since it provides a fireproof buffer between the radiant heat of the fire pit and the wood of the deck.
Fire Pits and Location Safety
Along with clearance, you should also consider the fire pit’s location on a wooden deck and its proximity to other structures on the deck.
Not only do you have to provide enough clearance for people to be able to sit three to five feet back from the heat of the fire, but you also need to ensure that pergolas and other deck structures are adequately spaced away from the radiant heat. Even if they don’t catch fire, extended exposure to a fire pit can cause discoloration and other damage to decking if it is located too close to vertical wooden surfaces.
It’s also a good idea to install a fire pit in a part of the deck that doesn’t see a high volume of foot traffic. The more people are walking through and around the fire pit to get to other areas of the deck, the more likely an accident is to occur where someone is burned on the pit.
Fire Pit Accessories for Deck Safety
There are several accessories you can buy for your fire pit that can make it safer to use on a wood deck. Here are some of them:
- Spark guards: Spark guards are screens that can be placed over a fire pit to help prevent sparks and embers from coming out of the fire pit and potentially starting a fire. Spark guards can also help prevent anyone from directly reaching into the fire pit and putting themselves in danger of a burn.
- Wind and flame guards: Wind and flame guards are usually square or rectangular glass partitions that are placed around a fire pit to both ensure safe clearance and also to prevent the wind from catching flames or embers from the fire pit and scattering them across the deck.
Having a wind and flame guard is recommended when installing a fire pit in a wood deck. Remember, though, that a glass flame guard will not protect against radiant heat combustion. (Source: Safti)
- Fire extinguishers and fire blankets: A fire extinguisher and a fire blanket are both good investments if you use any kind of fire on your wood deck, even if you’re only grilling. You never know when you’ll need to put out a fire quickly. Without fire control measures, a deck fire can quickly turn into a house fire. (Source: Bob Vila)
Wood-burning fire pits are more of a fire hazard than gas fire pits. So, if you’re installing one, you must consider fire safety accessories for your fire pit to make sure that you don’t accidentally catch your deck on fire.
Questions to Ask Before Building a Fire Pit
If you’re still in the planning stages of installing a fire pit in your wood deck, there are several questions you need to ask yourself to determine whether your deck is safe enough to do so.
Here are some of the things you should consider before doing it:
- Do you have enough space on your deck to allow proper clearance for the fire pit?
- Can you install the fire pit in a low traffic area where there is less likelihood of accidental burns?
- Is the fire pit location far enough away from pergolas, awnings, and other deck structures that could potentially catch fire?
- Is the deck strong enough to support the weight of the fire pit and a group of people around it? What is the weight of the fire pit you want to install, and can your deck handle it?
- Are there any flammable objects on the deck near where the fire pit would be that could combust from radiant heat?
- Does your city housing ordinances or HOA allow for a fire pit to be installed on a wooden deck?
- Do you have the technical know-how to install a fire pit yourself, or will you need help from a structural engineer or other contractors?
- What kind of base protection can you utilize to provide insulation between the fire pit and the deck?
Answering these questions is an important step before you purchase your fire pit. Otherwise, you might end up with a fire pit that is not safe to install or can’t be legally installed at all. Depending on where you live, this could result in consequences from minor HOA harassment up to a serious risk of fire in the home.
Fire Pits on Wood Decks Are Great but Should Be Installed Carefully
There’s nothing quite as picturesque and cozy as sitting around a fire pit on the back deck, but for you to do it safely, it has to be done right. Taking shortcuts in installing a fire pit on a wood deck is a recipe for disaster. So, if a fire pit is a renovation you’re planning for your outdoor space, you must consider all the possible safety angles before moving forward with the installation.