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Dokaflex 124 Soffit Support System image 1

Dokaflex 124 Soffit Support System

A fast, hand-set falsework system for concrete slabs up to 30cm thick.

  • Set out by eye, no measuring
  • Adapts to almost any slab layout
  • Deployed in minutes
  • Temporary Works Design available
  • Nationwide delivery
  • Competitive rates

Dokaflex 124 is a soffit and slab formwork system for soffit construction and suspended slabs up to 30cm thick. It is a hand-set timber-beam falsework: props stand on the floor, primary and secondary beams sit on top, and the formwork face goes on the beams to carry the wet concrete.

Using Dokaflex for your soffit formwork gives you a lightweight but capable system. Typical applications include:

  • Suspended floor slabs
  • Basement and podium slabs
  • Bridge decks
  • Floor slabs in apartments and offices
  • Hotels and high-rise frames
  • Downstand and ground beams

How the 1-2-4 system works

The 1-2-4 in the name is the system itself. Triangular marks along the timber beams act as a built-in measuring tape, so the layout can be set out by eye and without a tape measure.

  • 1 mark is the maximum spacing of the secondary beams
  • 2 marks is the maximum spacing of the props
  • 4 marks is the maximum spacing of the primary beams

Work to the marks and a quick visual check tells you the system has been set up correctly. With only two beam lengths in the kit, there is little to sort through on site.

Adapting Dokaflex to different slab layouts

The timber beams telescope, so the system flexes to the layout rather than the other way round. Downstand beams and floor extensions are handled within the system, and the beams close up neatly against columns and shear walls. The same kit optimises for different slab thicknesses and can shore filigree (precast) slabs. The beams take any form face you desire, so you get a first-rate concrete surface finish.

The Dokaflex kit

A few hard-wearing parts make up the system:

  • Doka H20 timber beams – a built-in shock absorber and ends sealed around the web, so they take the knocks of hire and resist moisture and UV
  • Eurex floor props – at least 20 to 30kN to EN 1065 Class D/E, light enough to set by hand
  • Lowering heads – strike the system with a hammer blow, no crane needed
  • 4-way heads – carry single or twinned beams depending on orientation
  • Folding tripods – hold the props upright and stable while you build

Temporary Works Design for Dokaflex slabs

Slab falsework is temporary works. Under BS5975 and the CDM Regulations, your temporary works coordinator needs it designed and checked by a competent engineer before the pour, and the beam marks alone do not cover columns, edge loads, back-propping or when it is safe to strike.

SEL's in-house Civil and Structural Engineers produce that Temporary Works Design: prop layout, beam spacings, loadings and the striking sequence, all to BS5975 and issued with the calculations and drawings your TWC signs off.

Common Questions

What is soffit formwork?
Soffit formwork (often called soffit shuttering on site) is the temporary decking that supports the underside of a concrete floor slab while it is poured and curing. It sits on top of falsework – vertical props on the ground carrying timber beams – which is what the Dokaflex 124 kit provides.
What does the 1-2-4 in Dokaflex 124 mean?
The 1-2-4 in Dokaflex 124 refers to the triangular marks printed along the Doka H20 timber beams, which work like a built-in measuring tape. One mark (0.5m apart) is the maximum gap between secondary beams, two marks (1.0m apart) is the maximum distance between floor props, and four marks (2.0m apart) is the maximum gap between primary beams. Setting out to the marks allows your site team to assemble the grid quickly by eye without a tape measure.
What types of concrete slabs and soffits can Dokaflex 124 support?
Dokaflex 124 supports almost any standard concrete floor slab or soffit layout. It is most commonly used for in-situ concrete slabs up to 30cm (300mm) thick, including residential floors, office podiums, basement slabs, and bridge decks. It also acts as temporary propping for precast beam-and-block or filigree (lattice girder) floor systems. If your slab is thicker than 30cm or carries heavy point loads, our engineers adjust the beam and prop spacings under a Temporary Works Design.
What support heights can Dokaflex 124 falsework reach?
Dokaflex 124 falsework covers floor-to-soffit heights from 1.5m up to 5.5m using single Eurex floor props. If your floor height exceeds 5.5m, or if you are working on a high-bay structure, single props are no longer suitable. For higher soffit heights and heavier loadings, we recommend using our Titan Aluminium Falsework Support System instead.
What props, heads and beams are supplied in the Dokaflex 124 kit?
The Dokaflex 124 kit supplies all primary components needed to erect the support grid: Doka H20 timber beams with protective end caps, Eurex floor props to carry the slab load, lowering heads to drop the beams with a hammer blow when striking, 4-way heads to hold single or twinned primary beams, and folding tripods to keep props standing stable during assembly.
Can Dokaflex 124 accommodate downstand beams and step-level soffits?
Dokaflex 124 can accommodate downstand beams, drop panels, and steps in soffit height within the standard system. Because the H20 timber beams overlap and telescope past each other, you are not locked into a rigid grid, and level steps are easily formed using Doka beam-forming brackets alongside standard timber beams.
How is the prop and beam grid determined, and can SEL supply a designed Dokaflex layout?
The Dokaflex 124 prop and beam grid is determined directly using the 1-2-4 beam marks for simple, regular slabs up to 30cm thick (secondary beams at 0.5m, props at 1.0m, primary beams at 2.0m). For more complex slabs – including irregular room shapes, step levels, heavy point loads, or site safety sign-offs – SEL's in-house engineering team can provide a full Temporary Works Design to BS 5975 with detailed prop locations, beam spacings, load calculations, and striking sequences.

Hire Dokaflex 124

To find out more about our Dokaflex 124 Soffit Support System and get latest rates, please contact our nearest depot.

Specification

ItemPropertyAdditional Information
Eurex Floor Props30kN CapacityAvailable sizes: 2.50m, 3.0m & 3.50m
Doka Folding Tripod TOP11.95 kg / 80cm HeightFor securing floor props
H20 Timber formwork beams200mm Depth 80mm Width 5.3kg/mAvailable sizes: 2.65m, 2.90m, 3.90m & 5.90m
Lowering HeadAllows for quick striking of the system by hammer blow lowering mechanism. Supports single or twinned beams.
4-Way U-HeadSupports single or twinned beams depending on orientation
Supporting HeadFor intermediate supports of primary beams

Dokaflex Typical Layout Drawing

Dokaflex User Guide

Installation sequence

Dokaflex installation sequence diagramDokaflex beam marking detail

A: Floor Prop with lowering head

B: Floor prop with supporting head

C: Secondary beams

D: Primary beams

X: 0.5m

Case Studies

Real slab pours our team has supported with Temporary Works Design, from basements to bridge decks.

Questions? Talk to SEL about Dokaflex 124 Soffit Support System

Our team is responsive, experienced and happy to help.

Products that work alongside Dokaflex on a soffit formwork pour, along with some alternatives

We can help with your next project.

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