Acrow Props, also referred to as jack posts or shoring posts, are designed to give construction teams the ability to safely support heavy overhead loads during the course of a building project. As the name implies, these tools are used to prop up large objects like walls and fixtures as you continue to work on and around them. In this guide, you'll learn the history of Acrow props as well as safety tips, available sizes, and how they're utilised in the construction industry.
It's important to note that construction props should only be used by licensed professionals, and this guide is more of an informational overview of how they're used rather than a set of step-by-step DIY instructions. Do not attempt to use Acrow props if you are not trained and licensed to do so.
A brief history of Acrow Props
Today's props were invented to serve as effective replacements for the wooden props that were widely used up until the 1900s. Construction crews had to create custom wooden props using timber, and each prop was cut to specification, which meant that they were typically only used for one job. Furthermore, the wood was susceptible to fire and moisture exposure, giving each prop limited long-term usability.
In 1935, William de Vigier invented the first Acrow prop as a cost-efficient and long-lasting alternative to wooden props. By 1939, there were more than 40,000 Acrow props in use throughout the UK, as Vigier had received a number of large orders from McAlpine & Sons as well as other prominent companies in the industry.
Today, Acrow props can be found at most construction sites and are considered the lone standard for propping up load-bearing objects. Below, we'll go over some common uses for Acrow props and steps that should be taken to ensure their safe installation and usage.
Common uses for Acrow Props
Generally, Acrow props are used for scaffolding or building support to aid in the completion of the following tasks or projects:
Wall removal or interior wall renovation
Adding a window, doorway, or archway to a wall
Installing reinforced beams and concrete sections
Bracing formwork for stairs, columns, and walls
Acrow props come in five main sizes – 0,1,2,3, and 4 – with the lower numbers indicating a stronger weight-bearing capacity. For example, Mother of All Props, whose products you can find via heatonproducts.co.uk, is known for their super heavy-duty size 1 Acrow prop.
Generally, selecting the minimum size needed to safely perform a job is sufficient, but opting for larger props ensures that you won't need to upgrade later on when you encounter a project with heavier load bearing requirements. In essence, the sizes are backwards compatible, so if you had a Size 1 Acrow prop, it could handle most tasks that a size 2, 3, or 4 could handle.
The base of an Acrow prop is highly compatible with other support types like timber needles, forkheads, strongboy brackets, and bracing couplers. Acrow props also adjust telescopically, making them ideal for use on walls and structures of varying heights.
Plus, they're lightweight and easy to transport, especially when you consider how much weight they can support. It's interesting to see a prop that can support part of a large building being easily stowed and transported with minimal space usage.
Safety tips for using Acrow Props
While any props sold in the UK are manufactured in compliance with national safety standard BS4074, the props are only durable and safe when they're used and installed properly. Here are several areas of concern you'll need to consider when installing and using Acrow props:
- Installation Tips
Selecting a proper location for installation is absolutely essential, as the sturdiness and stability of the prop will rely on the features of the points of contact. In particular, the ground, wall, and/or ceiling that's being supported or rested on for support must have the following features:
Completely level to ensure even weight distribution
Contain additional support for the prop's base-plate. Usually, sole boards are used for this purpose.
Stable and in good condition. Remediation should be carried out to improve the sturdiness of the surface before prop installation if necessary.
The upper surface of the load that will be supported should be checked to ensure that it will not collapse when the prop is bearing the weight. Furthermore, proper vertical positioning is essential and props should stand straight up, with a difference of less than 1.5 degrees from a perfect vertical line.
- Load Bearing
Any load bearing evaluations should be performed or checked by a qualified professional before the prop is used. Typically, load-bearing calculations are provided by architects or structural engineers. The additional weight of workers and equipment must also be taken into account when determining the potential weight of the load that will need to be supported.
It is unsafe to make up gaps between props using timber or any other substitute material. Additionally, all overhead loads must be fully supported by the Acrow props before any walls, beams, or other supporting structures are removed. Furthermore, walls should not have multiple openings being worked on at the same time – only a single section of the wall should be removed at a time.
- Maintenance & Inspection
After the Acrow prop is properly installed, it needs to be routinely checked throughout the course of construction to ensure that it doesn't loosen or shift. Props can move slightly when the wall is being opened or removed, so it's important to re-check positioning after any significant step in the project.
As a rule of thumb, all supportive props should be checked at the beginning and end of each workday, as well as at the start and finish of every task that the prop is being used for. Additionally, it's wise to have your props professionally inspected by a third-party at least once per week while they are in use – that way you're not leaving all of the liability on the workers.
It's important to be cognizant of any load changes as the project progresses. Keep track of how much weight is being added and be sure not to exceed the calculated load maximums provided by your architect or engineer.
Always wear safety equipment when using and installing Acrow Props
In closing, you should always wear appropriate safety equipment like hard hats, gloves, and goggles when installing and using any construction props. Furthermore, it's never a good idea to attach lighting, cables, or any other objects to the props, as a worker or piece of equipment could become entangled and accidentally shift the contact points.
Ultimately, Acrow props should only be used by competent professionals on an actual construction site. They are worthwhile investments for contractors and construction companies that regularly need to support structures for renovations and repairs.
If you're a new contractor or builder and you've never used Acrow props before, it's imperative that you take the time to educate yourself on the subject and seek professional consultation before performing a prop installation. Do not attempt to use Acrow props or any other heavy load bearing equipment at home or in a DIY context.