Lifting and Releveling Sequence

Purpose

On a lift, the stop rule governs. The target elevation is a ceiling the crew may not exceed, never a goal to chase, and the difference between those two readings of the same number is the difference between a controlled lift and a house with new cracks in it.

A settled structure has spent years finding a shape that its finishes, its plumbing and its openings have adapted to. Pushing it back moves every one of those, and some of them will crack on the way. What separates an acceptable lift from a damage claim is that somebody was watching instrumented cues, had a written threshold, and had the authority to stop the crew mid-increment. This procedure gives that person the threshold and the authority.

Before any load goes on the piers, the gas is off at the meter valve. A rigid gas connection is the one utility on a residential lift that fails without warning and kills people.

Scope

Covers the manifolded hydraulic lift of a foundation already piered and accepted, on residential and light commercial structures: pre-lift isolation, instrumentation, incremental lift, the distress stop rule, lock-off and post-lift verification.

Does not cover pier installation or capacity verification, which the pier installation standard owns, or the elevation survey method, which the elevation survey SOP owns and which this procedure re-runs unchanged. Does not cover slab lifting by polyurethane or mudjacking, and does not cover any lift requiring temporary shoring of the superstructure, which needs an engineered shoring design before a cylinder is charged.

Roles and responsibilities

Procedure

Step 1: Brief the customer and get the recovery expectation in writing

Say plainly, before any pressure, that recovery is not guaranteed, that the crew stops on structural distress rather than at a number, and that cosmetic cracking in drywall, tile and trim is an expected outcome of movement rather than a defect. Acceptance: a signed acknowledgment naming the target ceiling and the stop rule in the customer's file. Wrong looks like a crew starting a lift on a verbal understanding, which turns any stop short of the target into a dispute. Do not start; get the signature or reschedule.

Step 2: Isolate the utilities that cannot follow the movement

Shut the gas at the meter valve and confirm no appliance will light before the first increment. Locate the water service and verify slack where it enters, disconnect rigid appliance connectors in the lift zone, and scope any cast iron sewer lateral running under the slab in the lift zone before rather than after. Acceptance: gas off and verified, water service slack confirmed, rigid connectors freed, lateral condition recorded. Wrong looks like a lift started with the gas live because it is "only a little movement"; a rigid gas connection can part without any sound the crew will hear over a pump. Stop and isolate. If any gas odor appears at any point, everyone leaves immediately, nobody touches a switch, a garage door button or a phone inside, and the call goes to the utility emergency line from outside and upwind.

Step 3: Re-run the pre-lift baseline on the same grid you will use afterward

Re-survey the elevation grid using the same datum and the same point numbers the assessment established, re-read every crack monitor, and re-walk the door list. Acceptance: a complete pre-lift point list with its closure figure printed, plus current crack widths with their instruments named. Wrong looks like using a survey from a previous month as the baseline; anything that moved in the interval is now silently attributed to the lift. Re-run it the morning of.

Step 4: Instrument the lift before you charge a cylinder

Put a dial indicator or a laser receiver at each bracket, a monitor on the two worst cracks, and an interior watcher inside with the door list in hand. Acceptance: every bracket has a movement readout and every readout is zeroed and recorded before the first increment. Wrong looks like reading lift off the cylinder gauge alone, which tells you pressure and not movement, and the two diverge precisely when something is going wrong. Hazard: the interior watcher works alone in a building being moved, so they carry a radio or phone, know the exit route, and stay out of doorways with cracked masonry lintels overhead.

Step 5: Manifold the cylinders and set the sequence to the plan

Run the cylinders on a common manifold so the load rises together, and follow the sequence in the engineer's plan rather than the crew's habit. Acceptance: manifold connected, all cylinders reading, sequence written on the log. Wrong looks like lifting one bracket to catch up with its neighbors, which drives a point load into a footing that was designed for distributed support and cracks it. Hazard: high-pressure hydraulics. Never trace a leak with a hand, use cardboard; a fluid injection injury is a surgical emergency, so go straight to an emergency department and say it is a high-pressure injection injury. Relieve pressure before breaking any connection.

Step 6: Lift in fixed increments with a hold and a walk between each

Shop standard, tune it to your structures: 0.25 in per increment across all cylinders, hold 2 minutes, and the interior watcher walks the affected rooms before the lift lead calls the next increment. Acceptance: at each increment, cumulative lift, pressure at each bracket, every dial indicator, and every crack monitor are on the log before the next increment starts. Wrong looks like a bracket whose pressure climbs while its indicator does not move, which means something is yielding rather than lifting, usually a bracket losing its seat or a footing beginning to crack. Stop that bracket, back it off, and inspect before any further increment anywhere.

Step 7: Apply the distress stop rule at the first trigger, not the worst one

Shop standard, stated before the lift and tune it to your building stock: stop at the first of any monitored crack opening more than 1.0 mm beyond its pre-lift width, any new crack anywhere, any door that was free now binding, audible cracking or popping from framing, or movement at any bracket without a matching pressure change. Acceptance: the trigger and its measured value written on the log at the moment it fires. Wrong looks like a crew noting a trigger and finishing the increment anyway. Back off one full increment, hold, re-read, and if the cue relaxes, lock off there. If it does not, back off a second increment and call the design professional before doing anything else.

Step 8: Lock off at the elevation you achieved, not the one you wanted

Secure every bracket to the manufacturer's specification at the achieved position and release pressure in controlled steps. Acceptance: all brackets secured, cylinders relieved, and no indicator moving as the load transfers. Wrong looks like a bracket settling as pressure comes off, which means the lock-off is not carrying; re-charge that cylinder and re-secure before releasing the rest. Hazard: the manifold holds stored energy after the pump stops, so bleed it deliberately and keep hands and feet out from under any loaded bracket until every gauge reads zero.

Step 9: Re-survey, restore gas, and walk the result with the customer

Re-run the identical elevation grid, re-read every crack, re-walk the door list, then restore the gas. Relighting and the leak check at every disturbed joint are done by whoever holds the license for that work in your jurisdiction, using a listed leak-detection solution or a combustible gas detector; if a detector responds or an appliance will not relight, shut the valve and call the utility. Acceptance: post-lift point list on the same datum, achieved lift stated as a figure, gas leak check documented, punch list agreed and signed. Wrong looks like a crew leaving with the gas off and a note on the door. That is an unfinished job and a cold house, so stay until the appliance restart is verified or a licensed party is on site.

The record this produces

One lift log: the customer acknowledgment with the target ceiling and stop rule; the pre-lift point list with closure; the instrument zero readings; a row per increment carrying increment number, cumulative lift, pressure per bracket, indicator per bracket, and crack monitor readings; the interior watcher's observations; the stop event with its trigger and measured value; the achieved lift; the post-lift point list on the same datum; the gas leak check; and the signed punch list.

The lift lead closes it on site. The office attaches it to the warranty record. If a callback arrives a year later claiming a crack the crew caused, the increment rows are what show that the crack was measured before the lift, watched during it, and that the crew stopped when it moved.

One worked pass

Eight push piers already accepted under the pier standard. The pre-lift survey put the worst corner 1.6 in below the high point on the established datum. The engineer set the target ceiling at 1.2 in of recovery, and step 1's signed acknowledgment named both that ceiling and the 1.0 mm crack trigger. The stair-step crack at the garage return measured 1.4 mm pre-lift on a comparator card, and a plate monitor went on it.

Increments ran 0.25, 0.50 and 0.75 in cumulative with no trigger. Pressures tracked indicators within the expected spread and the interior watcher reported nothing on the door list. At the increment landing 1.00 in cumulative, the garage crack read 3.1 mm. Against the 1.4 mm pre-lift width that is 1.7 mm of opening, above the 1.0 mm trigger, so the lift stopped inside the increment.

Under step 7 the crew backed off one full increment to 0.75 in cumulative and held. The crack relaxed to 2.2 mm, which is 0.8 mm above pre-lift and inside the trigger, so the lift locked off there. Achieved recovery is 0.75 in against a 1.6 in deficit, about 47 percent, and the post-lift survey on the same grid put that corner 0.85 in below the high point. The target ceiling of 1.2 in was never reached and was never the criterion.

The customer asked the crew to keep going. The lift lead declined, wrote the request and the refusal into the log, and walked the customer to the monitor so they could see the number that stopped it. That conversation is survivable only because step 1 happened before the pump was ever started.

References

• 29 CFR 1926.1153 Table 1, respirable crystalline silica specified exposure control methods, where concrete is chipped or cored at a bracket during a lift.
• The pier and bracket manufacturer's published instructions, which set lock-off procedure and any limit on lift per bracket.
• The fuel gas code adopted in your jurisdiction, which governs who may reconnect and relight appliances and leak-test disturbed joints.
• See related: the pier installation standard for the capacity verification that must precede any lift, and the elevation survey SOP for the grid and datum this procedure re-runs before and after.