Even before we dug a shovel into our untouched backyard we knew we had to have a really good fire pit. It's something we have always had, in one form or another, at every home we have owned and it has always been at the heart of all of our family gatherings. When the pool was installed, we made sure to tee-off of the main line and run a "stub" for the natural gas we knew we would need (you may also be able to do this as a propane-tank tethered project, but you'll have to get some further outside advice on how to do it), however, the design of the fire pit itself was one of the last elements to get figured out. As the various areas of the outdoor space materialized over time, we kept searching for the right "pre-made" option and really just didn't find any that we loved. All the while, we kind of just knew we would have to eventually figure one out on our own.
If you've been following us for a while, you know that Joe is a bit of a DIY'er, and although whenever I begin to drop hints that maybe he could "just make something" he grumbles about it initially, he always quietly loves the idea of a challenge to figure it out. We considered a masonry version for a bit but the various stages seemed complicated. I also did not want to overwhelm the area with too much concrete or stone. Then Joe had the idea to use the same wooden landscape tie materials we had used to border our pavers and create steps throughout the yard. I wasn't sure about the idea (because I had never seen a wood fire pit), so he mocked up a design in photoshop using photos of the actual landscape ties and some lava rocks and fire images he found online. (You might note, the fire pit came out pretty close to what he illustrated)."Won't it burn?" I had asked skeptically. "No," he insisted. "The flames and the heat will all be above it so the heat will rise and it won't be a problem." He was right.
I had purchased my teak seating from iksun teak a couple weeks prior, so we situated it around the area to decide exactly where the fire pit would be. Once we knew the spot, we pulled up a couple pavers and had a licensed plumber bring the gas stub to exactly where the key valve would be.
CONSTRUCTING THE FIRE PIT
The quality of the landscape ties (which are pressure treated for outdoor durability) is important. Sometimes they have a greenish tinge to them and are beat up a bit. We had to call a couple lumber yards to find the best ones, which have a consistent warm brown/natural color and are straight, without bowing or gouges.
Landscape ties are usually 6 inches by 6 inches by 8 feet long.
So the plan was to simply make a square frame of landscape ties, stacked two high and held together with galvanized steel corner braces. We "sandwiched" the two lengthwise pieces between two end pieces. The final dimensions would be 48" wide by 53" long and 12" high.
Other than the plumbing for the gas line, the burner unit would be the most costly part. We felt it was really important to instal one made entirely of brass so that it would last for many many years. We also wanted to make sure the flames itself could be adjusted to be high and hot like a real camp fire, because so many pre-made versions don't put out enough heat to keep you warm on a cold night. We searched online and found the "Crossfire Burner System" made by Warming Trends, LLC. (BE SURE TO GET THE OPTIONAL KEY VALVE KIT). This unit is 30" from end to end and burns at up to 180,000 BTUs! It is also a match-lit system, meaning, you have to place a lit match or hold a long lighter near the burner element and then slowly turn on the gas to light the fire (so be extra careful!).
Once the "box" of the fire pit structure was assembled on top of the paver decking, using the two layers of landscape ties and the corner braces, the gas elements needed to be assembled by a licensed plumbing contractor. (THIS IS NATURAL GAS WE'RE WORKING WITH HERE... EVEN SOME DIY'S REQUIRE LICENSED PROFESSIONALS. SAFETY FIRST!) The box would be filled with road base or sand - 3 inches short of the top (be sure to compact it) with the burner element resting on the road base/sand. (See cross section).
Have the plumber test the valve and light the burner to be sure all is working correctly. Then turn the burner off and fill the last three inches with the tiny lava rocks all the way to the brim. You can then stack larger lava rocks on top to make the pile that the flames will dance through and heat whenever lit. VERY IMPORTANT that you use lava rocks... NOT river rocks or any regular rocks, which can explode when heated!!
A COUPLE NOTES ON USAGE:
Most nights, you'll only need to turn this up a tiny bit to get a good flame that can heat the area well.
A full-on quarter turn will produce a flame about 3 feet high.
Be careful in windy situations as the flame can get blown beyond the edge of the pit.
If you light this during the day, be extra careful because the flame can be hard to see at first.
Below are some other detail shots to give you a better idea of how this came together. GOOD LUCK!