How to safely build a gas fire pit on decking.

Fire Pit Safety, Uncategorized
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Having already built your outdoor entertainment area on a deck sometime in the past, you may decide to add a fire pit.

Gas Fire Pit On Wooden Decking

The big question is ‘how to safely build a gas fire pit on decking’

Wood-Burning Fire Pits

A wood-burning fire pit is a bigger problem because of the potential of flying embers, and spark screens are not 100% effective. As a result, you must cover a large area of your decking with a fire pit pad, perhaps not the most attractive look.

Temperature range underneath a fire pit

Gas Fire Pits

Flying embers are not an issue with gas fire pits. However, precautions must be taken inside the fire pit structure where temperatures are high. A wood deck can quickly become scorched and catch fire.

The vinyl or polyethylene shell surface of composite decking starts to degrade and melt at temperatures between 250 degrees F and 350 degrees F. It can soften at temperatures as low as 176 degrees Fahrenheit.

The surface temperature directly underneath the fire pit pan can be between 200-400 degrees F.

The Deck Insulation Kit recently released by HPC shows how with a couple of simple techniques during construction a gas fire pit can be safely installed on either a wood or composite deck.

The kit is specially designed to protect the deck surface from radiant heat and works with either a natural gas or propane fire pit.

Cross-section of a fire pit on decking surface

The core of the insulation is manufactured from flame-proof volcanic rock fiber ( Basalt ), and the top side is finished with an aluminum layer designed to reflect the heat radiating from the fire pit. The Insulation is easily cut with a standard utility knife and is very easy to install.

Deck Insulation kit Basalt Mat

When installed in accordance with the manufacturers’ instructions, the Deck Insulation Kit will keep the temperature well within the safety zone and way below the range that can cause damage to the decking.

HPC recommends installing the Insulation Kit on top of a layer of 1″ thick ( min ) paving blocks commonly found at your local builders’ store.

Deck Insulation Kit cut to fit gas pipe stub


Fire Pit Enclosure Construction on Decking


Before you start, check the following points.

Codes and Regulations:

In all industries Codes are notoriously slow in adapting to new technology and products, that’s just the way it is. If your fire pit project is subject to local codes be sure to check that the Code allows for the installation of fire pits on decking. If it does not legislate for it, then it is highly unlikely that using this product and methodology will be acceptable to the inspector.


Before you start building your fire pit on the decking ensure that the decking structure is strong enough to hold the extra weight. Some reinforcement may be necessary.