Slab Formwork
What the system is made of, how to calculate a kit per m² and in what order to install it
Prop-and-H20-beam slab formwork is the standard for cast-in-place floor slabs in residential and commercial construction. Formex rents it out, sells new and used kits and buys formwork back once your project is finished.
- Rental from 15 days
- New and used kits
- Buyback after the project
What slab formwork consists of
The parts work as one system: props carry the load, beams spread it, and plywood forms the underside of the slab
Telescopic props
Steel props made of two tubes with a pin and an adjusting nut. They take the weight of concrete, rebar and workers and transfer it to the base. Props in our rental fleet adjust from 1.7 to 5.5 m, each rated for up to 2000 kg.
Tripods
Folding stands that hold a prop upright until the beams are on it. Without tripods, props have to be held by hand, especially along the edges of a pour.
Unifork heads
U-shaped heads that slot into the top of a prop. One or two H20 beams sit in the fork, butted or overlapped, and the fork keeps them from shifting.
H20 timber beams
I-beams 20 cm deep. The lower layer is the primary beams resting in the forks; the upper layer is secondary beams laid across them, which carry the plywood.
18–21 mm film-faced plywood
The formwork deck. The film face gives a smooth soffit and does not soak up cement paste. 18 mm suits most slabs; 21 mm is for thick slabs and frequent reuse.
Shoring towers above 5.5 m
When the storey is taller than props allow, frame shoring towers with diagonals and adjustable jacks replace them. The beams and plywood on top stay the same.
System parts on their own:
How to calculate slab formwork per m²
The number of parts depends on slab thickness: the thicker the slab, the closer the props and the more beams per square metre
The table shows the ratios our online calculator uses (for storey heights up to 5.9 m). Multiply the slab area by the figure in the table, divide by 100 and round up to get the quantity of each part.
| Part, pcs per 100 m² | 200 mm slab | 300 mm slab | 400 mm slab |
|---|---|---|---|
| Telescopic props | 60 | 68 | 80 |
| Tripods | 24 | 40 | 52 |
| Unifork heads | 60 | 68 | 80 |
| H20 beams, total | 112 | 122 | 132 |
| Film-faced plywood sheets | 32 | 32 | 32 |
Example: a 12 × 10 m slab, 200 mm thick, is 120 m², so you need 72 props, 29 tripods, 72 forks, 135 beams and 39 plywood sheets. The final specification depends on openings, columns and storey height; our specialist will prepare it free of charge.
Slab formwork installation sequence
The typical order for a prop system with H20 beams
- 1
Prepare the base
Props stand on a level load-bearing base: the slab below or compacted ground with sole boards. Prop spacing is marked out from the design or from our specification.
- 2
Props and tripods
Set out the tripods, place the props in them and set the height: roughly with the pin, precisely with the nut, allowing for two layers of beams and the plywood thickness.
- 3
Forks and primary beams
Insert unifork heads into the props and lay the lower layer of H20 beams in them. Beam joints must fall on a fork.
- 4
Secondary beams
Lay the upper layer of beams across the primary ones at the spacing in the specification, then check that every prop is plumb and loaded.
- 5
Plywood and levelling
Lay the film-faced plywood, close the gaps at walls and columns and level the deck with the prop nuts. Then come the edge forms, rebar and the pour.
- 6
Striking
Formwork is struck once the concrete reaches the stripping strength set in the design: lower the props first, then remove the beams and plywood. Clean the parts and move them to the next pour or return them after rental.
A crew of 3–4 people installs about 100 m² of formwork a day. When you collect the formwork, we brief your crew on installation and striking.
Rent, buy or sell back: what it costs
Pick an option; full terms are on each service page
| Option | Price | Best for |
|---|---|---|
| Slab formwork rental | from 200 UAH/m² per month without plywood, from 300 UAH/m² with plywood | One project, a clear timeline, no storage space |
| New formwork | kit on request; props from ₴1,575, H20 beams from ₴530 per metre | Formwork that works on several projects in a row |
| Used formwork | cheaper than new; ask for price and availability | Owning formwork on a limited budget |
| Buyback of your formwork | set after inspection, depending on condition, volume and demand | The project is finished and the formwork is no longer needed |
The minimum rental order is 50 m² for at least 15 days. The final price depends on slab thickness, storey height and whether you need plywood.
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Slab formwork FAQ
Price, terms, kit contents and installation in brief
How much does slab formwork rental cost?
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A kit without plywood (props, tripods, forkheads, H20 beams) rents from 200 UAH/m² per month, and from 300 UAH/m² per month with laminated plywood. The minimum term is 15 days. The online calculator shows the parts needed for your slab; full terms are on the slab formwork rental page.
What are the minimum area and rental period?
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From 50 m² and from 15 days. If your volume is smaller or you need formwork for a long time, compare rental with buying new or used formwork.
Is delivery included?
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No, delivery is paid separately: from 700 UAH within Kyiv, calculated per order elsewhere in Ukraine. Unloading is included in the delivery price, and pickup from our warehouse is free.
What is in a slab formwork kit?
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Telescopic props, tripods, unifork heads and H20 beams. Film-faced plywood 18–21 mm is optional; if you have your own, you can leave it out. Above 5.5 m, shoring towers replace props.
What slab height can props reach?
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Props in our fleet adjust from 1.7 to 5.5 m. Shoring towers are used for greater heights.
What load can the formwork take?
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Each prop is rated for up to 2000 kg. Prop and beam spacing is chosen for the slab thickness, so thick slabs need more parts per square metre (see the calculation table above).
Do you help with installation?
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When you collect the formwork we brief your crew on installation and striking and answer questions by phone during the works. A site visit by our foreman is a paid service.
Is it better to buy or to rent?
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For a single project, rental usually costs less. If the formwork will work on several projects in a row, buying new or used formwork pays off. When the job is done, you can sell it back to us.
Didn't find your answer? Call us and we will work out a kit for your site free of charge
Call usKyiv. Bortnychi.
FORMEX LLC rents and sells formwork for monolithic construction.
info@formex.com.ua11 Bortnychi str. Lisova
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