Protect your deck or patio from the heat of a fire pit.

April 2018

Testing the Effect of a Fire Pit on a Composite Deck

We sell a product that we recommend placing under your fire pit. So what happens if you don't use DeckProtect? To find out, we tried it by burning a rigorous fire in a typical fire pit placed on composite deck boards. We ran this experiment on a very cold day and on a very warm day. Not surprisingly, we got very different results.


As much as people talk about fire pit risk for composite decking, we found it rather surprising that we could not find any tests online that showed exactly what the risk is. To be fair, there are a huge number of variables, so it is hard to imagine exactly how a certified lab would design the test. So why not just try it in a real world setting and see what happens? What we found out is illustrated on our Composite Heat Test page.

Christmas Trees and Fire Pits

You may already know this. I was frankly shocked when I discovered how effective a few sprigs from a Christmas tree are for getting a good fire going in a fire pit. Having missed the deadline in January for putting the tree on the street to be picked up by the town, we decided to cut the branches off and put them aside for warmer weather when we could safely dispose of them in the back yard. When warmer weather came, and I was trying to get a fire going in the fire pit, I remembered the Christmas tree branches. It turns out that a handful — seven or eight roughly ten-inch sections — of very dried out evergreen is more than effective for starting a fire. Explosive is the word that comes to mind. Within seconds, the fire is leaping skyward. Have some kindling too of course, not just hardwood logs. You may remember from your scouting days that a fire is built in pyramid or teepee form with the lightest kindling at the bottom and thicker pieces of wood on end leaning toward the center with space for air around and through the stacked wood. With dried Christmas tree sprigs at the center or your teepee, your fire will surely get going.


This photo is a stock photo from When I used parts of a Christmas tree to start a fire, I was jumping back, not taking pictures. So this tip for fire pit enthusiasts is also a cautionary tale for anyone setting up a real tree for Christmas. We have always heard that Christmas trees are a fire hazard, but I, for one, did not understand how absolutely explosive this combustible material can be. I hope that everyone will be very careful with their tree at Christmas, especially when it starts to dry out. And if you do decide to save some branches for your fire pit, please store them as safely as you would store gasoline.

Planning a New Deck

The first part of planning could be called dreaming. Go to Google images or Pinterest and browse hundreds of photos to get ideas. Imagine the good times you will have with friends and family and general outdoor living. Make a list of the things you want to do on your deck. 1.) Sit in a comfortable chair, protected from the wind or harsh sunlight while reading a book. 2.) Host a dinner party with an outdoor table set for six people. 3.) Cook great dinners on a grill. 4.) Sit around a fire pit. Etc. Plan a deck that will accommodate the particular forms of outdoor living you have in mind. You may need to extend the deck a couple more feet than you originally thought in order to provide ample space for a table surrounded by chairs and room for people to move around. Then you get down to the real planning to figure out construction details, materials, and costs. Even if you plan to have a contractor build your deck, you should go through a number of steps as if you were going to build it yourself. Then when you talk to the contractor, you’ll know what questions to ask, and you will be a much better judge of how qualified he is or how much attention he will give to your project.


A contractor generally takes responsibility for knowing what local ordinances are and for getting the building permit. However, you should look into this yourself and perhaps even discuss it with your local building inspector. In many communities there are zoning laws that limit the size of a structure relative to the size of your lot or how close your deck will be to the property line. Look into how deep the footings should be in your part of the country and for the particular nature of the terrain. The more you know beforehand the better. The contractor should know that he is dealing with a savvy customer.

Materials and Construction Techniques
A contractor may have a limited set of ideas when it comes to materials. He may have built a dozen decks in more or less the same way with the same kind of decking or the same style of wooden railings. There are so many other ideas and options that he may not have researched. Just a couple of hours at your computer will expose you to a vast array of options. The big question is whether to go with natural wood or with composite decking. That is a question worth researching. Even if you have already decided on a composite deck, there are different types of composite decking with different advantages and disadvantages. A great web site for planning and researching is You should also spend time visiting the web sites of manufacturers of decking, rail systems and other components.

Working with a Contractor
There are articles on line with tips for finding a good contractor. I would avoid using a referral service or web site that lists contractors who paid to be listed. It is always comforting to have a recommendation from a friend, but even then there are things to look out for. Even if your friend was happy with a contractor, that contractor might not be the best choice for your particular project. Good contractors are booked months or even years in advance. One thing to be particularly watchful for is scheduling. Deck contractors have a reputation for lining up a lot of jobs in the spring, knowing, but not being completely honest with you, that they wont’t get to some of the projects for months. Sometimes a contractor will take a cash deposit to seal the deal, then have materials delivered to your lawn where they will sit for four or five months before he starts the work. In the meantime, he has the deal locked up. Ask a lot of hard questions about scheduling and get the answers in writing.

Fire Pit on a Patio

Everyone knows that heat rises. So why worry about heat underneath a fire pit. Heat does not just rise of course; it also radiates, and over time, it can build up. So when the question comes up of whether it is safe to use a fire pit on a patio, the quick answer is yes, absolutely. It is safe… for you, but maybe not for the patio. I am not an expert on the subject of concrete and paving blocks, but I have been reading up on it. What can happen is that the concrete can eventually spall and crack. Spall means break up into little pieces. It might not happen. There are a lot of variables. If you use a fire pit once or twice on your patio on a cool day, you probably won't have a problem.


This photo was sent to us by a customer. A number of our customers have purchased DeckProtect for use on a patio. If you have invested in installing a beautiful patio that you want to enjoy for years to come, why take a chance on causing damage?

Built-In Fire Pit for Your Deck

If you're planning a new deck and know you want to have a fire pit, you can build the fire pit into the deck. The result can be very cool. Check out Google images under decks with built in fire pits. This kind of fire pit is most commonly round and built of stone. It is really an outdoor fireplace with no chimney. Built in fire pits can be surrounded by decking or they can be set in a circle of stone or tile. Contractors often build a circular bench around one side. This kind of fire pit is more elegant than most portable fire pits and certainly a lot more expensive. Aside from cost, though, there are some limitations. All of the built in fire pits I have seen pictures of are ground level. I am sure it would be possible to build a fire pit into a raised or second-story deck, but it would take some pretty special construction technique. Another limitation is that part of your deck will always be where a fire pit is. You can't use it for anything else. The advantage of a portable fire pit is that you can move it. Place it on the deck in September or October when the evening weather is perfect for sitting around a fire, and put it in the garage when you would rather have a glass table with an umbrella to sit around. Or in July, put an inflatable pool for little kids in that part of your deck. Another thing I would think twice about is the beautiful built in bench in a semi circle around the fire pit. My preference would be a chair that I could pull in closer to the fire to roast a marshmallow or stoke the fire with a poker. I would like option of moving the chair to a different side of the fire pit to avoid being downwind of the smoke. Built in fire pits are so elegant that I really would want one… if I had enough space and enough budget to build a sprawling, perhaps multi-level, deck with additional room for a dinner table, lawn chairs and whatever else. With limited budget and space resulting in a deck that you will want to use in a variety of ways, I would recommend an easily moved portable fire pit and of course a very easily moved DeckProtect to go under it.