Boulder County Building Publications
Propane Tank Installation and Location - B23

B23 Propane Tank Installation and Location
Per the 2021 IFC (International Fire Code) Section 6104

Propane Tanks

Propane tanks can be a real hazard to firefighters and homeowners alike during a fire. Tanks can easily be heated by radiant energy from a burning house or vegetation.

Generally, as the tank begins to pressurize from the heat, it will begin by venting excess propane into the atmosphere through a valve in the top of the tank. This can cause a dramatic “torch” effect from the tank. More serious, though, is the possibility of tank over-pressurizing, causing a rupture.

This usually occurs when the tank is nearly empty and there is more gas than liquid in the tank. The valve may no longer function in this case, and a dramatic

depressurization may occur (i.e. an explosion). For these reasons, propane tanks (and other kinds of pressurized tanks) must be treated with special care in areas subject to periodic wildfires.

Propane Tank Installation

When installing a propane tank on your mountain property, remember the following:

• Propane tanks are generally set on a concrete pad for proper support. If the concrete is limited to small pads under the feet of the tank, you should surround the rest of the tank with weed barrier and crushed rock or gravel.
• Keep combustible materials away from propane tanks. Don’t stack firewood or scrap lumber near the tank. (IFC-6107.3)
• Don’t put the tank directly underneath a tree. Keeping the tank in the shade zone of trees is fine, but don’t allow tree branches to overhang the tank. Vegetation within 10 feet of the tank must be kept cleared. (IFC-6107.3)
• If screening the tank from view is desired, try to utilize a natural feature, such as a rock outcrop. Wood fencing around the tank is a bad idea; try a dry stacked rock or block wall instead. Deciduous shrubs or small trees (such as aspen) may be used as screening, as long as they are kept 10 feet away from the tank. Do not use highly flammable shrubs (like juniper bushes) as screening!
• If you are purchasing a propane tank (as opposed to leasing), consider an underground unit. While there are some additional costs associated with such buried tanks, they are preferable to above ground tanks in high wildfire hazard areas, since they won’t be exposed to radiant heating from a fire like above ground tanks would be. They also stay cooler and aren’t as visible on a day-to-day basis.\
• Consider the location where you wish to place the tank on your lot. Protective measures may be required to protect the tank and piping from damage, including but not limited to vehicle damage from impact due to proximity to the vehicle traffic ways, driveways, or parking areas.

Documents Required at Permit Application

• Provide a site plan that indicates the proposed location of the liquid propane (LP) tank. Please note on the site plan the distances from the proposed liquid propane tank location to the property lines, driveways, parking areas, buildings, and other lot improvements. Please indicate a cardinal direction (north) on the site plan.
• On the construction documents, note the type of propane tank proposed. Is it an above ground installation or a below grade / buried tank installation.
• The construction documents must indicate the capacity of the propane (LP) tank. How many gallons is the LP fuel tank designed to hold

All construction drawings must be submitted in PDF format at the time of your online building permit application:

Website: Boulder County Permit Records & Online Application Submittals.

International Fire Code (IFC) Table 6104.3: Location of LP-Gas Containers

Theses are the footnotes for table 6104.3 as published in the 2021 IFC:

For SI: 1 foot = 304.8 mm, 1 gallon = 3.785 L.

a. Minimum distance for underground LP-gas containers shall be measured from the pressure relief device and the filling or liquid-level gauge vent connection at the container, except that all parts of an underground LP-gas container shall be not less than 10 feet from a building or lot line of adjoining property that can be built on.

b. For other than installations in which the overhanging structure is 50 feet or more above the relief-valve discharge outlet. In applying the distance between buildings and ASME LP-gas containers with a water capacity of 125 gallons or more, not less than 50 percent of this horizontal distance shall also apply to all portions of the building that project more than 5 feet from the building wall and that are higher than the relief valve discharge outlet. This horizontal distance shall be measured from a point determined by projecting the outside edge of such overhanging structure vertically downward to grade or other level on which the LP-gas container is installed. Distances to the building wall shall be not less than those prescribed in this table.

c. Where underground multicontainer installations are composed of individual LP-gas containers having a water capacity of 125 gallons or more, such containers shall be installed so as to provide access at their ends or sides to facilitate working with cranes or hoists.

d. At a consumer site, if the aggregate water capacity of a multiple-container installation, comprised of individual LP-gas containers having a water capacity of less than 125 gallons, is 500 gallons or more, the minimum distance shall comply with the appropriate portion of this table, applying the aggregate capacity rather than the capacity per LP-gas container. If more than one such installation is made, each installation shall be separated from other installations by not less than 25 feet. Minimum distances between LP-gas containers need not be applied.

e. The following shall apply to above-ground containers installed alongside buildings:

1. 1. 1. LP-gas containers of less than a 125-gallon water capacity are allowed without a separation distance where in compliance with Items 2, 3 and 4.
      2. Department of Transportation (DOTn) specification LP-gas containers shall be located and installed so that the discharge from the container pressure relief device is not less than 3 feet horizontally from building openings below the level of such discharge and shall not be beneath buildings unless the space is well ventilated to the outside and is not enclosed for more than 50 percent of its perimeter. The discharge from LP-gas container pressure relief devices shall be located not less than 5 feet from exterior sources of ignition, openings into direct-vent (sealed combustion system) appliances or mechanical ventilation air intakes.
      3. ASME LP-gas containers of less than a 125-gallon water capacity shall be located and installed such that the discharge from pressure relief devices shall not terminate in or beneath buildings and shall be located not less than 5 feet horizontally from building openings below the level of such discharge and not less than 5 feet from exterior sources of ignition, openings into direct vent (sealed combustion system) appliances, or mechanical ventilation air intakes.
      4. The filling connection and the vent from liquid-level gauges on either DOTn or ASME LP-gas containers filled at the point of installation shall be not less than 10 feet from exterior sources of ignition, openings into direct vent (sealed combustion system) appliances or mechanical ventilation air intakes.

f. This distance is allowed to be reduced to not less than 10 feet for a single LP-gas container of 1,200-gallon water capacity or less, provided that such container is not less than 25 feet from other LP-gas containers of more than 125-gallon water capacity.

g. Above-ground LP-gas containers with a water capacity of 2,000 gallons or less shall be separated from public ways by a distance of not less than 5 feet. Containers with a water capacity greater than 2,000 gallons shall be separated from public ways in accordance with this table.

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