When to Use Formwork Props For Sale?

21 Apr.,2025

 

Props for Construction: 3 questions to choose the most optimal

Props for Construction: 3 questions to choose the most optimal

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Do you have to buy or rent props for your construction site, but you don’t know which type of prop is the best and most optimal?

With competitive price and timely delivery, Zolo sincerely hope to be your supplier and partner.

It is true that there are many types of props, and some important aspects must be taken into account when assessing the product.

Let’s see them!

1.- What are props?

Props are auxiliary elements that support a horizontal formwork system and position it at the required height in each case.

As load-bearing elements, they are responsible for transmitting to the ground the loads they receive when the structure is concreted, and act as support until it is put into service, once it has reached the necessary strength to absorb the necessary stresses.

They are height-adjustable and telescopic. They are generally comprised of two hollow cylindrical bodies which facilitate regulation, one inside the other (body and shaft). In some cases, as a complement, they may have a locking system to prevent the shaft from separating from the body, as well as an unloading system to facilitate removal and disassembly.

2.- What type of props are there?

There are many types of props, depending on to the material they are made of, the load they can support, and their service life. They are also classified by whether the adjustment thread is visible or covered.

Steel props 

Metal props are the most commonly used, and can be painted, galvanized, zinc plated, etc… They are classified according to their load capacity (between 500 and kg) and their working height (generally covering a span height between 2 and 6 meters). Steel allows the determination of a well-defined load capacity and has a long service life, being a resistant material (controlling the oxidation of the material).

They are compatible with recoverable formwork systems for both building and civil works, facilitating the construction of all types of solid slabs or lightened slabs, both unidirectional and bidirectional (waffle slabs with lost or recoverable cassette), within their load and height range.  They are also commonly used as shoring elements in building rehabilitation.

Aluminum props

Aluminum props are of more restricted use due to their high price, they are lighter than steel props, and have a shorter service life, because aluminum is more ‘delicate’ to on site treatment. They can have a higher load capacity and allow working at greater heights.

Although they can be used as a stand-alone prop, they are generally mounted “tied” together, forming load-bearing towers with bracing frames. It is also common to join them in height.

They are used with formwork systems for singular buildings and/or for civil works, when there is a higher load and height range than steel props.

Wooden props

Wooden props are the most ‘archaic’ in construction, and were used before the advent of steel props. They are still used in some parts of the world, especially in less developed areas or where wood is very cheap. In general, they have less load-bearing capacity than steel props, a short service life and, according to legal regulations, their use is not allowed in most parts of the world.

3.- What factors should be taken into account to choose the most suitable one?

You have to shore a slab, with a certain weight, an acting load, at a certain height: What factors should be considered when choosing the most suitable type of prop for a given application?

There are 5 factors to consider so as to determine the most optimal prop:

  1. Acting load: First of all, you have to calculate the acting load per m2 which your props will have to support. Always remember to add to the weight of the slab itself, the overload of execution (weight of the workers, formwork, …).
  2. Prop load capacity: Each prop has a minimum load capacity for each free height, determined by the manufacturer, by a table according to its class (local regulations or European standard EN). The prop load depends on the diameter of the cylindrical body, the thickness of the tube, the geometry of the prop itself and its ability not to buckle.
  3. Free height of the prop: It is important to know the free height at which the prop will work on site. This is very important in order to obtain the load capacity according to the manufacturer’s data (point 2). Of course, the more headroom there is, the more the load capacity of the prop will be reduced.
  4. Number of props: Once the data described above have been determined, the minimum number of props to be placed under the slab must be calculated, depending on the acting load and the load capacity at the free working height.
  5. Price: Finally, never forget the price factor: of course optimizing the prop according to the preceding points will allow to find the right prop, with the required minimum load capacity and the cheapest price.

Choosing the right prop seems easy, but as you have seen, a very important analysis must be carried out beforehand. In any case, if you have any doubts, contact your trusted supplier for advice!

If you want to learn more, please visit our website Formwork Props For Sale.

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How to Use Acrow Props - Australia Scaffolding & Formwork

Acrow Props are an essential tool for formwork shoring worldwide, offering high-strength support for vertical loads. Our step-by-step explains how to use Acrow Props and their common uses in construction.

William de Vigier created the prop in the s as an alternative to the custom-built timber props of the time. Their adoption became widespread across the construction industry when Sir Robert McAlpine began utilising them.

Organise a Consult With a Relevant Professional

Before beginning any work, it is essential to understand:

  • How much vertical weight requires support;
  • Is the floor capable of supporting the weight;
  • Whether Strong Boys or Timber Needles are needed; and
  • How many props, Strong Boys or Timber Needles are required to safely support the load?

Sourcing a structural engineers’ opinion will help inform you of the appropriate amount of Acrow Props to use. If you are unsure where to look, many wholesale suppliers provide services with trained professionals or can refer you in the right direction.

Supporting beams, roofing or masonry without the input of an engineer is reckless. Any attempt only places the worksite, workers, and yourself at risk of injury or death.

Purchase Acrow Props With The Correct Height and Capacity

Since their creation 90 years ago, Shoring Props have sold in six standard sizes. Each size is capable of supporting the weight capacities seen in the table below.

Acrow Prop Capacity Table

The weight capacity of the props in use must exceed the weight they are supporting. We always recommend additional props in the unlikely event that another fails. Taller Formwork Props trade capacity for height, meaning more are necessary for taller structures.

How Many Acrow Props Per Metre?

On most consultations, engineers will recommend an Acrow Prop for every metre, a common rule, but not always correct for the job at hand. Props should always be evenly spaced to ensure an even load.

Prepare Load-Bearing Surfaces

Further work may be required to create a load-bearing surface. The risk of collapse and injury is great if the floor joists and timber below cannot withstand the load of the props.

Any load-bearing surface must be flat, even and capable of withstanding heavy loads. Workers risk damaging the floor’s integrity even if it doesn’t collapse.

Timber floors are often susceptible to damage even when they are capable of supporting Acrow Prop loads. It is still important to conduct checks for certainty. Concrete surfaces are ideal for supporting heavy loads.

Erect The Acrow Prop Then Secure The Top And Bottom Plates

Start by lifting the inner tube and insert the prop pin to set an approximate height. The, use the handle on the adjustable collar to fine-tune the prop to the exact height required. Continue rotating to tighten, using a wrench as leverage if necessary.

Make sure the prop is firmly is plumb and cannot move. A props load-bearing capacity is severely affected when it sits at an angle beyond 1.5 degrees.

Let the load rest on the prop. The Acrow Prop itself should be supporting a structural beam or joist. Check props at the start and end of each workday and keep them set up until the completion of the project.

It’s important to stay aware that the weight props are supporting can change throughout the project. You should be mindful of this and ensure that any changes won’t exceed the load capacity of the props. Check out our quick video below as a visual guide.

Install Strongboys and Timber Needles for Supporting Masonry

An optional step that is only required when supporting masonry.

Brickwork and Masonry require these add-on tools as they need horizontal support instead of just vertical.

Strong Boys slot on top of Acrow Props and extend outwards into a removed section of brick. Multiple Strong Boys can support a brick wall above where it sits.

Timber Needles operate on the same principle and slot into where brickwork was. They act as a platform to evenly distribute weight between two props supporting the needle from below. Needles are advantageous for long-term projects with heavy loads.

Our guide will help you avoid simple mistakes and create a safe working environment.

Buy Formwork Props online or collect in-store at our Dandenong or Laverton branches in Melbourne. We also offer delivery nationwide. If you have any more questions on how to use Acrow Props, call us at 622 686 or us through our website.

Contact us to discuss your requirements of Scaffolding For Sale. Our experienced sales team can help you identify the options that best suit your needs.