At Buckingham Structural Moving Equipment, we have spent decades building the jacks, dollies, and rigging gear that house movers and structural contractors rely on every day. Our 15-ton crib jacks are a backbone of the house lifting industry, and the questions we field from new crews, homeowners, and general contractors tend to come back to the same handful of fundamentals.
This FAQ pulls those questions into one place. Whether you are about to lift a 200,000-pound farmhouse, replace a failing foundation, or simply trying to understand what your contractor is doing under your home, the answers below explain how house cribbing actually works, and how to do it safely.
The Basics: What House Cribbing Actually Is
What is house cribbing?
House cribbing is the process of temporarily supporting or lifting a structure using an engineered system of hydraulic jacks, lifting beams, and stacked crib blocks. The cribbing — those interlocked stacks of hardwood or steel timbers — carries the structure between jack strokes, holding the load safely in place while the crew prepares the next lift cycle or completes work below.
Contractors use house cribbing for foundation replacement, house relocation, flood-elevation projects, sill plate repair, floor joist work, and any job where the building has to come off its existing support and stay safely suspended for hours, days, or weeks.
How does the cribbing process work, step by step?
Every job is different, but the lift-and-crib sequence is universal:
- Steel or timber carrying beams are inserted under the structure, usually through openings cut in the foundation wall.
- Vertical crib towers, alternating layers of hardwood timbers, sometimes called box cribs, are built up under the carrying beams to act as primary load-bearing columns.
- Hydraulic crib jacks are placed beneath the carrying beams. The crew pressurizes the jacks, lifts the structure a short distance (often an inch or two), then transfers the load onto a fresh layer of cribbing.
- The jacks are retracted, another layer of blocks is added, and the cycle repeats. Movers in the field call this “pack as you jack” or “lift an inch, crib an inch.”
- Once the structure reaches its target elevation, the crib towers hold the load while foundation work, transport rigging, or repairs happen underneath.
The key idea: the structure never rests on the jack alone. Cribbing is what makes the operation safe, the jack provides force, and the crib tower provides the secure load path between cycles.
What is the difference between cribbing, blocking, and shoring?
These terms get used interchangeably, but they describe slightly different jobs:
- Cribbing — stacked, interlocked blocks (typically a box crib) that form a temporary load-bearing tower under a lifted structure.
- Blocking — individual blocks or wedges placed to chock, level, or fill a small gap between a load and its support.
- Shoring — engineered vertical posts (often steel jacking-shoring posts) used to hold a load between lift cycles or while permanent supports are installed.
On a typical house lift, all three are happening at once. The crib towers do the heavy holding, blocking and wedges fine-tune contact, and shoring posts lock elevation in place once the structure is up.
Equipment: Crib Jacks, Blocks, and Power
What is a crib jack and how is it different from a regular hydraulic jack?
A crib jack is a heavy-duty hydraulic jack purpose-built to work inside a cribbing system. Unlike a general-purpose bottle jack, a crib jack has a robust base designed to sit stably on a crib tower, heavy-duty seals that hold pressure under sustained load, and predictable stroke and capacity ratings the crew can plan around.
Buckingham crib jacks are rated at 15 tons each and built in the USA. They are available in 9-inch and 17-inch stroke lengths, and in both single-acting (gravity return) and double-acting (powered retract) configurations. Single-acting jacks keep things simple; double-acting jacks reset faster between cycles, which matters when you are running ten or twelve jacks under a single structure and trying to keep them in sync.
How many crib jacks does it take to lift a house?
There is no single number, it depends on the weight of the structure, the geometry of its load-bearing walls, and the capacity of the jacks. As a rough planning starting point, crews divide the total structure weight by the working capacity of each jack (which is always well below the rated capacity, to build in a safety factor) and then add jacks at every primary load-bearing wall, chimney, fireplace, or concentrated load point.
A modest single-story home might lift on six to eight 15-ton crib jacks. A larger two-story with masonry chimneys, brick veneer, or interior load-bearing walls often needs ten to twenty jacks running off a unified jacking machine so every point rises at the same rate.
What are house cribbing blocks made of?
Most cribbing blocks are hardwood timbers cut in standard sizes such as 4×4×24 or 6×6×24. Some crews use softwoods like Douglas Fir or Southern Yellow Pine because they crack audibly and visibly before failing, giving an early warning if a stack is overloaded. Engineered composite timbers and plastic cribbing have also entered the market for crews that want consistent, lab-rated load ratings and resistance to moisture, oil, and rot.
Whatever the material, the rules are the same: blocks must be straight, sound, free of cracks or rot, and of a known load rating. Damaged or unknown-history blocks have no business under a house.
Why are crib blocks stacked in a crisscross pattern?
The crisscross is what makes a box crib a stable column instead of a fragile stack. It distributes load across multiple contact points, keeps the stack square as it grows, and provides resistance against tipping or racking as the structure shifts.
As a rule of thumb, the height of a crib tower should not exceed three times its base width. Build it taller than that without engineered guidance and the stack becomes prone to instability, especially under uneven or shifting loads.
What is a unified jacking machine and when do you need one?
A unified jacking machine is a hydraulic power unit with multiple ports that lets a single operator drive every jack on a project simultaneously and at the same rate. Without unified jacking, each jack has to be pumped individually, which makes it nearly impossible to keep a large structure rising evenly.
Unified jacking is the standard for any serious house move or full-structure lift. It is what prevents racking, cracking, and the differential movement that destroys plaster, drywall, masonry, and tile when one corner of the house gets ahead of the others.
Use Cases: When House Cribbing Gets Called In
When does a house need to be cribbed?
Cribbing comes into play any time the structure has to be lifted off its existing support or temporarily held while work happens underneath. The most common scenarios:
- Foundation replacement — the home is lifted, the old foundation is demolished and rebuilt, then the home is set back down.
- Flood elevation — the home is permanently raised onto a taller foundation to meet floodplain or insurance requirements.
- House relocation — the structure is lifted, transferred onto dollies, moved to a new site, and set onto a new foundation.
- Sill plate, beam, or floor joist repair — localized lifting to access and replace structural members.
- Adding a basement or crawl space below an existing slab-on-grade home.
- Correcting settlement, leveling sagging floors, or addressing foundation failure.
Can you crib and lift any type of house?
Most residential structures can be lifted, but condition and construction type matter. Wood-framed homes — the dominant residential type in North America — are well suited to lifting. Solid brick, stone, or masonry structures can also be lifted, but they demand more cribbing points, more careful load planning, and often interior bracing because masonry has little tensile strength and cracks easily under uneven movement.
Homes in poor condition — rotted sills, failing framing, severe settlement — sometimes need extensive pre-lift reinforcement before any crib jack goes under them. A qualified structural mover or engineer should evaluate the building before a lift plan is finalized.
DIY, Hiring, and Equipment Sourcing
Can a homeowner do their own house cribbing?
We will be direct about this: a full house lift is not a DIY job. The equipment, training, engineering, and insurance required to safely lift hundreds of thousands of pounds of structure are beyond what is appropriate for a homeowner project. Localized work, like cribbing under a single beam to replace a section of sill, is something experienced builders sometimes handle, but it still requires properly rated jacks, sound cribbing material, and a clear understanding of load paths.
If you are a contractor expanding into structural work, the right path is to train under an experienced structural mover, then invest in professionally engineered equipment from a manufacturer that supports the industry.
Where do contractors buy crib jacks and cribbing equipment?
Buckingham Structural Moving Equipment has been supplying the house moving and structural lifting industry for decades. Our 15-ton crib jacks — in 9-inch and 17-inch strokes, single-acting and double-acting configurations — pair with our jacking-shoring posts, unified jacking machines, power packs, toe jacks, multi-purpose jacks, push-pull rams, dollies, and the SmartSteer® advanced dolly system to make up complete lift-and-move setups.
We sell new equipment, professionally refurbished used equipment, and rental units for crews scaling into larger projects. Every piece is built in the USA and engineered to perform under the real conditions of a working job site, not just on a spec sheet.
Talk to Buckingham About Your Next Lift
House cribbing is a high-stakes operation where the quality of the equipment and the precision of the execution determine the outcome. Investing in properly rated crib jacks, engineered cribbing, and continuous monitoring is not optional, it is what separates a successful lift from a structural failure.
If you are planning a project, whether it is a single foundation replacement or a full structural relocation, our team can help you spec the right jacks, power, and accessories for the job. Browse our crib jacks and accessories, or call us to talk through what your lift actually needs.
Buckingham Structural Moving Equipment. Built in the USA. Trusted by structural movers all over the country.
