ELEVATOR BORINGS
4725.7250 ELEVATOR BORINGS.
The rules regulate the construction of an excavation for the installation of an elevator hydraulic cylinder,
sometimes referred to as a “jack hole,” or “elevator jack.” The rules do not regulate the construction of the
elevator car, the shaft the car operates in, cable elevators, or hydraulic jack holes for purposes other than elevators
such as car lifts at automobile service stations. The well and boring rules also do not regulate “holeless” or
“limited access” elevators where the depth of the hydraulic cylinder and pit is
10 feet or less.
In addition to MDH regulation of elevator borings, some aspects of elevators are regulated by the DLI.
Subpart 1. General. An elevator boring must be constructed according to the general
construction standards in parts 4725.2010 to 4725.3875 and cased, sealed, and
maintained according to this chapter to prevent the vertical movement of water.
Subp. 2. Casing. The boring must be cased to the bottom of the excavation.
In order to contain hydraulic fluid leakage, the rules require two things: first, that the hole is cased the entire
length; and second, that protective measures be taken to prevent fluid loss to the ground (the requirements of
subpart 4). Unlike water-supply wells, the casing must extend to the bottom of the bore hole. While it is not
specifically required, this will typically result in rock holes having at least two casings: a surface casing to rock,
and an inner casing to the bottom. The casings must follow the inner/outer casing combination requirements of
Minnesota Rules, part 4725.2250 (3.0-inch or 3.5-inch size difference). The annular space between the casings
must be grouted with neat-cement or sand-cement grout.
Subp. 3. Exception. The boring is exempt from the requirements in parts 4725.2150;
4725.2175; 4725.2185; 4725.2250, subpart 8, concerning extension of the casing 12
inches above the established ground surface; and 4725.2250, subpart 11.
An elevator boring is exempt from:
● The required separation distances from gas pipes, liquid propane tanks, and electric transmission lines;
● The prohibition from location inside a building;
● The required 3-foot separation distance from a building; and
● The requirement to extend the casing 12 inches above ground.
All other construction, maintenance, and sealing requirements of Minnesota Rules, parts 4725.2010 through
4725.3875 and this rule part apply.
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Subp. 4. Hydraulic fluid leakage protection. Hydraulic fluid must be protected from
leakage by:
One (or more) of the three methods for leakage protection must be used on new installations and (as specified in
subpart 5) when a cylinder is removed and replaced.
A. attaching a watertight cap or plate to the bottom of the casing and surrounding the
casing with neat-cement or cement-sand grout. The grout must extend at least three
inches above and inches below the bottom of the casing. The grout must be inserted
according to part 4725.3050, subpart 2;
The cap or plate must be of material equivalent to the casing. The cap must be welded or threaded to the bottom
of the casing.
B. grouting the inside of the casing with cement-sand grout or neat-cement grout. The
grout must extend at least two feet above the bottom of the casing and be inserted in
accordance with part 4725.3050, subpart 2; or
C. encasing the hydraulic cylinder in a Schedule 30 plastic outer pipe or sleeve with
the bottom of the pipe or sleeve capped and the top extending above the pit floor.
The plastic sleeve is not a structural casing, but a “container” to catch leaked hydraulic fluid. The plastic sleeve
does not have to be 3.0 inches (or 3.5 inches) smaller than the casing, since it is not a structural part of the boring.
Materials heavier than Schedule 30 may be used. The joints of the pipe must be solvent welded or threaded
watertight. The sleeve must be large enough to hold all the hydraulic fluid in the hydraulic system or constructed
so that hydraulic-fluid leakage overflowing the sleeve will not run into the casing.
Subp. 5. Repair. In addition to the requirements of part 4725.3750, when a hydraulic
cylinder is removed from an elevator boring for repair or replacement, the boring must
be protected from hydraulic fluid leakage according to subpart 4.
Subp. 6. Sealing. An elevator boring which is unsuccessful or no longer in us, must be
sealed according to part 4725.3850. The hydraulic cylinder, debris or obstructions, and
sand placed around the hydraulic cylinder must be removed prior to sealing.
STAT AUTH: MS s 103I.101; 103I.111; 103I.205; 103I.221; 103I.301; 103I.401;
103I.451; 103I.501; 103I.525; 103I.531; 103I.535; 103I.541; 103I.621; 144.05; 144.12;
144.383; 157.04; 157.08; 157.09; 157.13
HIST: 17 SR 2773; 33 SR 211
4725.7400 [Repealed, 17 SR 2773]
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