Acrow Props are an extremely versatile product that can be found on many construction sites. They are commonly used on construction sites to provide a quick and easy method of providing temporary support for reinforced concrete beam and floor formwork. Acrow Shores are equally useful as Raking Shores to support column, wall and stair formwork. They are invaluable on repair jobs, demolition or to replace a permanent support, to support canopies, lintels and the like while placing bricks or concrete.
Acrow Struts consist of two circular steel tubes, an inner tube with a top plate that slides up and down freely inside an outer tube that is attached to the base plate. The inner tube is pre-drilled along its entire length so you can quickly extend it to just below your desired height and insert a steel pin to lock in that length. To extend the strut to the correct height, the top of the outer tube is threaded on and a collar, which is similar to a nut on a bolt, picks up and holds the steel pin. So turning the collar and moving it up extends the inner strut. This allows you to achieve the exact height required.
The ‘Acrow Prop Safe Installation Guide’ gives you a checklist of what to check before you even get started and then shows you what to check to ensure the safe installation of your Acrow props. Once installed, there is a list of items that should be checked regularly to ensure the continued safe performance of your acrow prop installation and then ends with a checklist for safe removal.
Pre-Installation Checklist
- Start by planning the work. Make sure you have the correct number and size of accessories. Inspect the site and, if necessary, mark the locations of the struts.
- Have you correctly selected the correct size props for the job? Do you have enough to bear the weight? Never exceed the Safe Working Load (SWL) for your specific size props. Consult the manufacturer’s load charts. If you are unsure, consult your engineer or other responsible person who will consider the weight of the upper structure to be supported and determine the correct size and quantity.
- It is the responsibility of the user to check the struts each time before they start working. When inspecting accessories, items to check include:-
- Check that the inner and outer tubes are straight and slide easily.
- Check that the collar rotates freely around the thread and that the tread is not damaged or blocked.
- Check that there is no damage to the pin. If the pin is secured with a chain, make sure it is still attached. If equipped with a wraparound pin, it is not necessary to secure it with a chain. Use only the original pin, do not use any other pin.
- Do not attempt to repair any defective accessories. If an accessory is faulty, it must be tagged and isolated immediately and must not be used.
Installation Checklist
- Warning fittings that are designed to be used in compression MAY NOT be used in tension.
- Always use the proper safety equipment when using this equipment.
- Make sure the work area is cordoned off to prevent public access, only essential people should work in the area.
- Make sure the struts are installed by qualified people who have the necessary knowledge and experience to do the job safely.
- It is important that the stanchion be installed vertically to ensure that it can support the specified load. Struts should never be used more than 1.5 degrees from vertical, as this can substantially decrease their capacity. This is approximately 2 inches (50 mm) off true vertical for every 6 feet (1.8 m) of length.
- Make sure the base plate and top plate of your strut are sitting squarely on the surface. Also make sure that the floor surface and ceiling surface are strong enough to support the weight that will be placed on them.
- When the props are supported on a flexible surface, such as a gravel surface, each prop must be supported on a wooden base or equivalent. A wooden sole should be at least 9 inches (225 mm) wide by 1.5 inches (38 mm) thick. It must be long enough to protrude at least 300 mm (1 ft) on each side of the strut base plate. A soleplate can also be used on top of the main plate to help distribute the load if required. If you are unsure or have any questions, consult your engineer or other competent person.
- Acrow struts come in 5 different sizes, so don’t use struts that are too short to fill the space with wood. Always use the correct length Acrow strut.
Post Installation Checklist
- Struts left to support a curing slab can loosen over time. As the slab cures it naturally shrinks which can cause the strut to loosen so it is recommended that these be inspected and retightened regularly by a competent person.
- As a minimum, all fixtures should be inspected at least once a week.
- Make sure the area is safe from the general public if fixtures are to be left in place unattended.
- Do not string or tie anything to the struts.
Accessories Disposal Checklist
- Start by planning the work.
- Always use the proper safety equipment when using this equipment.
- Make sure the work area is cordoned off to prevent public access, only essential people should work in the area.
- Make sure the struts are removed by qualified people who have the necessary knowledge and experience to do the job safely.
- Do not remove or adjust any accessory until you are sure it is safe to do so.
- Always return the equipment to the rental company clean.
Always seek professional advice before undertaking any shoring/shoring project. A shoring job gone wrong can be disastrous, life threatening and an extremely expensive exercise to repair.