Check Oil Tank Legs, Feet & Piers

Rusty or tipped oil tank support legs or piers risk an oil spill

Oil Tank Leg or Pier Inspection Points

Here are two key indicators problems with the support of an oil storage tank that any home owner or home inspector can examine as long as the tank is visible and accessible in or at a building.

Are the tank support legs sound and on firm footing? A standard 275-gallon tank with an average capacity of 260 gallons weighs about 2000 lbs. Placed on wood or dirt the tank is likely to tip and spill.

If required by local ordnance, is other tank support in place?

The photo shows a seriously tipping oil tank support pier, risking tipping of the tank, oil spillage, loss of heat (risking frozen pipes and water or mold damage) and environmental contamination.

That tiny line level is being held in an approximately level position so that you can see that in less than three inches the support for this oil tank foot is tipped by nearly an inch: risking a tipped-over oil tank and an oil spill disaster.

Photo courtesy Arlene Puentes, Kingston NY

What about rusty oil tank feet? The rust shown in the photo just above is trivial in that it has not caused enough damage that we have any concern that the tank is going to tip over - at least not in the near future.

Compare that with the collapsing rusty oil tank leg at the top of this page.

But rust on oil tank supporting feet for an indoor oil storage tank, especially on those back feet close to the wall, hard to reach, and hard to re-paint, are a great indicator of the history of water entry in a building.

What about just skipping oil tank feet entirely. Why can't we just sit the oil tank on the ground?

Steve Vermilye (photo at left) looked concerned for a reason. This oil storage tank had not much besides luck holding it up, and in addition, the tank was not designed for ground-contact.

This oil tank installation is inviting rust perforation of the oil tank or a tipped-over oil tank spill and loss of heat all at once.

Oil Tank Protection From Vehicles or from Tipping-over

Regardless of whether an oil tank is installed indoors or outdoors above ground, it must be properly supported.

Some municipalities also require installation of special protection to assure that a tank cannot tip over, even if its feet are damaged.

A steel pipe may be installed in the floor next to the tank and extended vertically above the tank and then after making a 90 deg. bend, secured to the wall to "cage" the oil tank.

Our photo (left) shows steel piping installed to protect an outdoor oil tank from tipping over.

Where oil tanks are installed in garages, some jurisdictions require that the garage oil tank (and boiler or furnace if one is present) also be protected from being struck by a vehicle using similar iron pipe guards as just cited above.

See PROTECTION BOLLARDS for MECHANICAL EQUIPMENT

Also see additional visibly detectable oil tank defects listed

at Home Inspection Report Language Library: Visible Defects in Oil Tank Installations, Tanks, and Heating Oil Piping.

NFPA & Other Standards: requirements for support and anchoring of oil tanks

Photo: this buried oil storage tank, not secured, floated up out of the ground when this property in Rhinebeck, New York was subjected to flooding.

• PLASTIC OIL TANKS 5-YEAR INSPECTION PLAN NYS DEC [PDF] (2007), NYS DEC, Five-Year Inspection of Plastic Tanks (DER-16), DEC Program Policy [PDF] (2007) New York State Department of Environmental Conservation, retrieved 2021/06/27 original source: https://www.dec.ny.gov/regulations/38102.html
  
  Excerpt:
  
  [Buried Oil Tank Anchors] "b. Foundations & Supports
  
  Only properly graded and leveled surfaces having adequate physical characteristics shall be used for foundations. Tank anchors should be installed to allow for the tank expansion/flexure; improperly installed anchors may initiate cracks in the tank.
  
  Flat bottomed tanks should only be installed on a smooth, flat base.
  
  Manufacturers typically specify a deviation from nominal level depending on the tank size. Care must be taken to ensure that the base is free of debris. All installations shall follow manufacturer's specifications where available.
  
  Where wind-loading calculations require the use of tie-down bolts, these must be correctly installed using the brackets or steel girdle attached to the tank.
  
  All of the requirements of 6 NYCRR section 598.3 must be followed when tanks are installed within a flood plain."
• NFPA 31 mentions "API Standard 650, Specifications for Welded Steel Tanks for Oil Storage", from the American Petroleum Institute, for guidance on SEISMIC protection for installation of above-ground tanks.
  
  It also addresses wind load on tanks, and raises awareness of "sloshing" and resulting "uplift" of supports, which could result in shifting and collapse.
  
  
• Similarly, like outside propane tanks, oil tanks in areas subject to FLOODING must be properly secured to prevent them from floating away, rupturing the pipes. - 2 Feb 2015 NHFireBear - a building code expert who has frequently contributed to InspectApedia.