HOW TO BUILD A GAS FIRE PIT
The first thing to do when considering a fire pit is to check your local code. There may be regulations that can greatly affect what you had in mind. It is a good idea to use the installation manual of your chosen gas fire pit kit (tray, burner, ignition system) to design a compatible structure. Provide the gas fitter with the technical details to ensure the correct sized gas pipes are installed. We recommend that you use a certified gas technician for the installation of your gas lines and the connection of your fire pit.
Marking out your Fire Pit
If you are starting from scratch then footings will ensure that your structure will have a good stable base upon which to sit. To mark out your footings, place a stake in the centre of the proposed site, attach a length of string and keeping it taught, walk around the centre point marking the outer perimeter of the fire pit as you go. Repeat for the inner circle.
Footings, Drainage, Gas and Electricity
Using the above markings as a guide, dig a trench for the footings. You will also need to dig trenches for your gas lines and electricity conduits, if these are required, as well as for your drainage. Good drainage is essential to protect your fire pit kit components from becoming submerged in water. All gas and electrical work carried out should in accordance with local or National code.
If you are also laying a patio around the structure then all concrete and/or rebar work can be done at the same time. The inner floor of the structure should be sloped toward the drain hole and have a smooth concrete or tile finish.
Fire Pit Structure
Whatever the shape or size, your structure must be ventilated. This is important for two reasons. 1- Ventilation allows for the dissipation of gas in the event of a leak. 2- The airflow prevents overheating of the components. Check with the manufacturer of your equipment and local code, but generally, vents on at least two opposing sides of the structure totalling 36 in. sq. should be sufficient.
Depending on the type of fire pit kit you buy, you will need openings within the structure for the controls and emergency shut-off valves. The structure shown here is for a match-lit fire pit kit, the most basic of ignition systems. It only requires access for a gas key valve. Please see our guide for Gas Fire Pit Ignition Systems for more details.
LP burners require a tray, whilst natural gas burners do not. However, they are still a good idea for two reasons. Trays reduce the amount of fire media you need to buy and make access for maintenance much easier. Trays can either be the flat type or the drop-in variety. Both, however will need to sit on a stable, level support. A collar such as the one shown in fig. A can be mortared into the structure or sit upon built-in supports as shown. You could even use brackets anchored into the structure for support. In fig. B, a complete inner support wall has been built to support the tray. Recess the burner below the top of the structure to help prevent blow-outs.
The exterior of the structure can now be finished in accordance with your design. Capping stones are added as the final touch. There should be a slight overhang on either side to allow water to run off directly onto the floor. This will prevent stains resulting from water running down the wall. Install a drain grate. Cover the vent openings with grills to prevent debris from entering and potentially blocking the drain.
Installation of equipment
You are now ready to install and connect up the equipment. Follow the manufacturers instructions. Test all gas connections for leaks with soapy water and ensure that everything is working as it should before finally putting your fire glass or other fire media in place. Use only recommended fire media and follow the manufacturers instructions regarding its maximum depth, as well as the minimum diameter of the media itself. Ensure that nothing is directly blocking any of the gas outlets of the burner as this could cause back pressure. For LP equipment this may result in gas leaking from the air mixer into the cavity under the fire pit. Do not block vents or pilot openings with fire media.
Read and follow the safety guidelines for fire pit operation. Cover your fire pit when not in use. This will not only keep out debris which has to be removed prior to use but also protect your equipment from the elements.