On almost every construction site, a building is only as safe as the temporary system holding it up while it is still weak. Before beams, slabs and columns have cured enough to carry their own weight, or before an excavation is backfilled, the entire structure leans on a temporary shoring system. Skipping or under-engineering this step is one of the fastest ways to turn a routine task into a collapse. This is why temporary shoring matters, which jobs demand it, and what to look for when choosing the right support.
What Is a Temporary Shoring System?
A temporary shoring system is a set of support members placed under, beside or around a structure to hold it steady until permanent elements take over. It is installed for a specific phase, then removed once the work is done. This temporary nature is what separates shoring from the permanent columns, beams and foundations it protects.
The most common form on a building site is the adjustable steel prop, often called an acrow prop, used to support formwork, slabs under construction, and walls during repair. In its simplest shape a prop is a threaded steel column that adjusts to a set height, resting on a base jack at the bottom and carrying a U-head jack or timber at the top. Around these props, more complete systems such as high-load shoring towers and modular ringlock frames deliver higher capacity for heavier pours.
Why Temporary Shoring Is Critical On Every Project
Shoring exists for one underlying reason: concrete and soil do not gain full strength overnight. Until they do, something must safely carry the load. The consequences of getting it wrong are serious enough that the function of temporary shoring should be understood by everyone involved in planning, not just the site engineer.
1. Prevents structural collapse. Fresh slabs and beams sag and crack if their weight is not distributed while the concrete cures. An adjustable prop transfers that load to the ground so early-age concrete is not overstressed.
2. Protects workers and equipment. Collapsing formwork and trench walls are among the most dangerous failures on site. A properly rated shoring system holds everything in place so crews can work underneath, above and beside the supported area.
3. Makes deep excavation and trenching safe. When ground is removed, surrounding soil wants to slide in. Shoring holds the soil face back so basement, footing and utility work can proceed without trench collapse.
4. Protects neighbouring structures. In built-up urban areas, deep excavation or demolition can disturb properties next door. Lateral and vertical shoring keeps those buildings stable while work continues on your own site.
Common Types of Temporary Shoring
The right system depends on what the load is, its direction, and what the site allows. The main families are easy to tell apart once you know what each one does.
Dead (vertical) shoring uses vertical props under load-bearing members that have been removed or are not yet strong enough. It is the standard choice for slab support, propping formwork, and holding walls during underpinning. Raking shoring adds inclined props beside a leaning or weakened wall to brace it laterally, typically at an angle between 60° and 75°. Flying shoring ties two opposing walls together with horizontal members where no ground support is possible, and trench or hydraulic shoring braces excavation walls with adjustable struts or hydraulic pistons for quick installation and removal.
For heavier loads, engineered systems such as high-load props and ringlock towers distribute weight across multiple legs. A heavy duty shoring prop built for slab pours and bridge formwork carries far more than a standard prop, which is why load tables, not guesswork, should drive the choice.
How to Choose the Right Temporary Shoring
Four factors shape most choices, and they should be weighed together rather than in isolation.
Load and height. The imposed load, slab thickness and working height set the prop size, spacing and whether a single prop or a full shoring tower is needed. Always work from the manufacturer’s load tables. Soil and depth. Loose ground and deep cuts demand stronger lateral support. Site space. Tight city plots may rule out ground-based supports and push you toward flying shoring. Duration. Short, fast jobs favour lightweight, quick-strike systems.
Materials, Standards and Longevity
Steel quality and corrosion protection decide both the safe working load and how many projects a system survives. Strong, dependable props are typically formed from Q235 or Q355 steel, and adjustable prop classes are defined in standards such as EN 1065, while wider access and support systems often follow EN 12811 or BS performance requirements. Whatever the standard, protection matters: hot-dip galvanizing resists rust and extends service life far beyond uncoated steel, which is why durable prop systems are galvanized, powder-coated or pre-galvanized for outdoor use.
A genuine one-stop supplier should be able to pair the props with the crown plates, collars, connecting pins and jacks that keep the assembly square and stable. This completeness is often what separates a system that works on the drawing board from one that works efficiently on site.
Safety Practices for Temporary Shoring
Even a well-built prop fails if it is set up carelessly. Consistent discipline around a few basics keeps a temporary shoring system reliable.
Install on a firm level footing. Every prop should sit on a solid base plate or a properly sized base jack that spreads the load and keeps the column on a true line. Load within rated capacity. Never exceed the load in the approved tables and keep props vertical, with lateral bracing where height makes instability a risk. Inspect regularly. Re-check props and connections after each pour, after striking, and whenever loads change. Let trained crews do the work. Only competent people should erect, adjust and remove shoring, and movement of the supported structure should be monitored throughout.
Conclusion
A temporary shoring system is the safety net that holds every project upright during its most vulnerable phase. From a single adjustable prop under a curing slab to a full high-load tower supporting a bridge pour, the principle is the same: distribute the load, hold the structure steady, and keep people safe. By choosing the right system, following load tables and working with a supplier who understands the full range of temporary shoring products—and the jacks, collars and accessories to go with them—contractors can move from one phase to the next knowing the ground underneath is solid.