Formwork support · adjustable steel props
Shoring jacks
Shoring jacks are adjustable steel props that support concrete formwork during pouring and the 21-day cure. Riyadh Timber stocks them **at 1.8 to 3.5 m extension, with 20 to 35 kN load capacity, certified to EN 1065 and BS 4074** — the standard slab support on Saudi towers, infrastructure, and Vision 2030 mega-projects.
What is a shoring jack?
A shoring jack is an adjustable steel prop that supports concrete formwork vertically during pouring and curing. The jack consists of an outer tube, inner sliding tube, threaded collar, and U-head plate. Riyadh Timber stocks jacks at 1.8 to 3.5 m extension and 20 to 35 kN capacity, certified to EN 1065 and BS 4074.
Shoring jacks transfer the weight of fresh concrete plus form dead load through to the floor below. The threaded collar adjusts for fine height, while the inner tube slides through the outer tube for coarse extension. A pin or wedge locks the inner tube in position before the load is applied.
Jack class is identified on the body: a 'Size 0' jack covers 1.8 to 3.0 m, 'Size 1' covers 2.1 to 3.3 m, 'Size 2' covers 2.4 to 3.5 m. Larger 4.0 m and 4.5 m jacks are available on order for high-clearance work.
Why are shoring jacks used on Saudi construction sites?
Shoring jacks are used because they adjust on site to the exact slab height and absorb up to 35 kN per jack of vertical load. Compared to scaffold tubes, jacks save erection time, accept fine adjustment, and meet EN 1065 standards required by Saudi project consultants on towers and infrastructure work.
On Riyadh tower projects, shoring jacks support floor slabs at 1.2 to 1.5 m grid spacing. Each jack carries the slab dead load plus the live load of crews and equipment during pouring. Steel jacks rated to EN 1065 are mandatory on Aramco, SABIC, and Royal Commission for Riyadh City projects.
Compared to telescopic timber struts and scaffold tube assemblies, steel screw jacks are 60% faster to erect, accept micrometric height adjustment via the threaded collar, and survive 100+ project cycles with routine maintenance.
What are the specifications of shoring jacks?
Shoring jacks ship in three size classes covering 1.8 to 3.5 m extension with safe working loads of 20, 25, 30, and 35 kN. Steel grade is S235JR or S275JR per EN 10025, finish is painted or hot-dip galvanised, threaded collar pitch is 12 mm, and load tests follow EN 1065 with a 2:1 safety factor.
| Size 0 — closed length | 1,800 mm |
|---|---|
| Size 0 — extended length | 3,000 mm |
| Size 1 — closed length | 2,100 mm |
| Size 1 — extended length | 3,300 mm |
| Size 2 — closed length | 2,400 mm |
| Size 2 — extended length | 3,500 mm |
| Outer tube diameter | 60 mm OD, 3 mm wall |
| Inner tube diameter | 48 mm OD, 4 mm wall |
| Safe working load | 20, 25, 30, 35 kN by class |
| Steel grade | S235JR or S275JR (EN 10025) |
| Finish | Painted or hot-dip galvanised |
| Standards | EN 1065 · BS 4074 · SBC 502 |
Where are shoring jacks used on a construction site?
Shoring jacks are used in slab and beam shoring, deep-beam supports, formwork stages for cores and columns, temporary props for repair and renovation, and propping of precast elements during installation. Jack class is selected by the load and clear height of each application.
- 01
Slab and beam shoring
Adjustable jacks at 1.2 to 1.5 m grid spacing support slab forms during the pour and 21-day cure on towers and infrastructure work.
- 02
Deep-beam supports
Heavy-duty 30 to 35 kN jacks support transfer beams, deep ribs, and cantilever soffits where standard 20 kN jacks are insufficient.
- 03
Core and column formwork
Jacks brace climbing or jump formwork against wind and shutter pressure on towers, supporting up to 35 kN per anchor point.
- 04
Repair and renovation propping
Temporary support of damaged slabs, beams, or arches during structural repair, with jack heights matched to existing soffit elevations.
- 05
Precast erection propping
Jacks plumb and align precast walls, columns, and beams until welds, bolts, or grouted joints reach full strength.
What is the difference between shoring jacks and scaffold tube props?
Shoring jacks deliver adjustable support with 20 to 35 kN per jack and EN 1065 certification, while scaffold tubes require additional clamps, base jacks, and ledgers to form a load-bearing tower. Jacks erect 60% faster, but tube assemblies cover greater clear heights above 4 m where single jacks reach their limit.
Scaffold tubes paired with clamps and base jacks deliver clear heights up to 8 m or more — beyond the reach of any single shoring jack. The trade-off is erection time and certification: scaffold tower assemblies require an engineer-stamped drawing and a competent scaffolder.
On floor-by-floor tower work with 3 to 3.5 m clear heights, shoring jacks are the standard answer. On infrastructure projects with viaduct decks 5 to 8 m above ground, scaffold tube falsework or modular shoring towers are specified.
| Attribute | Shoring jack | Scaffold tube prop |
|---|---|---|
| Load capacity | 20 to 35 kN single | Variable, depends on assembly |
| Clear height | 1.8 to 3.5 m | Up to 8 m+ |
| Erection time | Fast — single piece | Slow — multi-component |
| Adjustability | Threaded collar — fine | Tube length — coarse |
| Certification | EN 1065 / BS 4074 | EN 39 / BS 1139 (assembly) |
| Best fit | Slab shoring 3 to 3.5 m | Falsework above 4 m |
| Indicative price | SAR 75 to 280 / jack | SAR 28 to 95 / tube + clamps |
How do I choose the right shoring jack for my project?
Pick the jack class by clear height and load: Size 0 for 1.8 to 3.0 m, Size 1 for 2.1 to 3.3 m, Size 2 for 2.4 to 3.5 m. Match SWL to the slab tributary area — slab thickness × jack spacing × concrete density × 1.5 safety. For loads above 35 kN per point, double up jacks or specify heavy-duty class.
Apply a 2:1 safety factor to the calculated load and pick the jack with the next-step SWL above. Verify the jack's stamped EN 1065 mark and SWL plate before site issue. Reject jacks with bent inner tubes, damaged threads, or stripped collars.
Galvanised jacks resist Riyadh's coastal humidity and dust storms better than painted finish. Specify hot-dip galvanised for jacks expected to remain on site through more than one wet season or in coastal projects on the Red Sea and Eastern Province.
How are shoring jacks installed on a Riyadh site?
Install jacks on timber sole plates over compacted ground, plumb to within 1° of vertical, with U-heads aligned to the slab soffit elevation. Set initial extension on the inner tube with the locking pin, then take final height with the threaded collar. Inspect each jack at hour 1 and 4 of the pour for settlement.
Sole plates distribute the jack base load over the floor below, preventing point loading on green concrete or screed. Plumbing is checked with a spirit level on two faces of the outer tube. The locking pin must seat fully in the inner tube hole before the threaded collar is wound up.
After the pour, remove jacks only when the concrete reaches 75% of design strength — typically 14 days for normal-weight concrete in Riyadh's summer temperatures. Striking too early causes mid-span cracking and re-pour cost.
Do shoring jacks meet Saudi Building Code requirements?
Riyadh Timber's shoring jacks meet EN 1065, BS 4074, and SBC 502 site-safety provisions, with mill certificates of steel grade and SWL test reports for each shipment. Vision 2030 mega-projects require third-party load testing on representative jacks — Riyadh Timber arranges witnessed testing on request.
Each jack carries a stamped SWL plate and an embossed EN 1065 mark on the outer tube. The site engineer logs the jack lot and inspection date on the formwork erection record. Jacks failing in-service inspection — bent tubes, damaged threads, missing pins — are tagged and removed from the site.
Which Saudi projects use shoring jacks from Riyadh Timber?
Riyadh Timber shoring jacks support NEOM, Red Sea, Diriyah, Qiddiya, and New Murabba, the King Abdullah Financial District towers, Riyadh Metro stations, and high-rise residential projects across Olaya, Hittin, and Al Malqa. Jack rentals run from 200-piece site supplies up to 5,000-piece tower mobilisations.
- Vision 2030 mega-projects: NEOM, Red Sea, Diriyah, Qiddiya, New Murabba — slab shoring on superstructure works.
- King Abdullah Financial District and Olaya towers — slab shoring under post-tensioned floor plates.
- Riyadh Metro stations and elevated viaducts — propping of precast and cast-in-place transfer beams.
- High-rise residential in Hittin, Al Malqa, Al Yasmin — slab and balcony shoring through superstructure phase.
What are common questions about shoring jacks?
**100 jacks** is the effective delivery minimum, sufficient to shore a typical 250 m² floor slab at 1.5 m grid spacing. Smaller orders pick up from our Olaya yard, or are bundled with an existing project shipment near the contractor's site.
We rent shoring jacks on **monthly contracts**, with rental rates from SAR 8 to SAR 18 per jack per month depending on size class and contract duration. Sale prices range SAR 75 to 280 per jack. Rental contracts include delivery, return, and replacement of any failed piece.
Size 0 jacks carry **20 kN at full extension and 30 kN at closed length**. Size 1 jacks carry 22 kN extended and 32 kN closed. Size 2 jacks carry 25 kN extended and 35 kN closed. Always derate by 1.5 to 2.0 safety factor against the calculated load.
Yes. Our shoring jacks ship with **EN 1065 mill certificates and witnessed load test reports** on request. These satisfy Aramco SAES-Q-001 and SABIC engineering-standard reviews on industrial and petrochemical projects.
Galvanised jacks survive **100+ project cycles or 10+ years** with routine cleaning of the threads and replacement of damaged inner tubes or pins. Painted jacks are 60 to 80 cycles. Damaged tubes are tagged out of service immediately under SBC 502.
Yes — under **timber sole plates levelled to within 1° of horizontal**. Sloped floors require packing under the sole plate, never under the jack base. Jacks installed off-vertical lose up to 30% of rated SWL — site engineers verify plumb before pour.
Yes. **Forked U-heads, swivel U-heads, and 150 × 150 mm base plates** are available with each jack order at SAR 12 to SAR 25 per piece. Heavy-duty 200 × 200 mm base plates for high-load applications are available on request.
What products relate to Shoring jacks?
Selections that complement the work in Saudi construction projects.
Need a quote on shoring jacks for your project?
Send the slab area, clear height, and project duration. We respond with a formal rental and sale quote within 4 working hours — unit prices, total, lead time, and EN 1065 certificates included.