ECCENTRIC PROP PRO-TECTOR,
SIMPLY SAFER TO USE.
Self-employed builders, employers and employees can only discharge their obligations under British legislation (C.D.M 2015) to the extent that the relevant information provided by manufacturers, retailers, the structural engineer and the H.S.E allow. Where the information and guidance is either absent, assumed, doctored, or inadequate, as would generally appear to be the case with regards to both the eccentrically loaded Acrow prop and the tongued prop attachment, it is not possible for these obligations to be satisfactorily met. Workers are not in possession of the correct information to be judged truly competent to make informed decisions and/or to identify the risks to an acceptable standard, especially when the hazards are unusual and hidden from the workers view; as they are concealed by no warnings, a lack of guidance and also hidden within the products testing un-certainties, flaws & faults.
Both products lack basic information about compatibility with each other and a safe configuration of use. The out-dated and manipulated maximum safe working loads are quoted for both components individually and not for use together of which has created a false sense of security to the end user.
Inadequate Design/Safety Factor calculations and no Working Load Limit (WLL) is used, when the existing double entendre of the maximum safe working load of both products is clearly taken at a measurement of 215mm of eccentricity from the old/redundant written instructions.
The increased measurement of eccentricity within the new written instructions is now 365mm, (150mm further eccentricity). This working load is clearly variable due to a greater distance of eccentric loading, (further from the Acrow props central axis) and is clearly inadequate; which requires both products to be tested together to clarify an acceptable working load limit of which should include a correct factor of safety calculation, minimum X10 down to 4 if a work-force is working underneath. This would prevent further accidents and will also protect workers, clients and the general public as it is not possible to manage health and safety when a product is supplied with hidden risks and incorrect guidance and is permitted to be used to prevent internal wall damage upon occupied living accommodation and when open plan living design has increased the size of openings within a typical rear extension of a property. A structural engineer providing and deceiving a client with false information/guidance that is purchased in good faith, is not only dangerous but also fraudulent when the calculations are not within the laws of physics.
An eccentrically loaded Acrow prop Max 25mm 1,700Kg and reducing when raised.
Tongued prop attachment Max 340kg and reducing when the Acrow prop is raised and when the measurement of eccentricity increases.
Ask your structural engineer why do they use assumed maximum safe working loads for every calculation, when both products are variable and not safe?
The main cause of collapse when altering masonry is due to the manufacturer, the retailers, the structural engineering organisations and the HSE suppressing the knowledge of the builder.
EXPERIENCE THE DIFFERENCE FOR LESS
SAVE Over £7.00 When Purchasing in Multiples
The Pro-Tector ensures secure contact with the face & underside of the wall for increased prop & wall stability and prevents the tongue from bending.
Increases the variable working load & prolongs the working life of an attachment.
Reduces the risk of overloading (Acrow prop guidance is also provided).
The missing factor of safety X 4 when eccentrically propping.
Designed to fit onto a variety of different brands of attachment.
Identifying and also resolving the systematic problems of propping eccentrically.
As all propping methods rely on the unknown lateral strength of the structure to work correctly, also use the Brick Brace on lime mortar masonry and when suitable.
As every task of altering masonry is different, each opening should be planned upon its own merit and carried out safely by using the most suitable variety/combination of temporary masonry support equipment, of which stabilises and supports all of the masonry (to avoid injury from falling debris) and to provide sufficient fitting access without dangerously overloading the equipment from the weight of the structure.
Do not comment on a project until knowing all of the information required to discuss and to plan correctly within accordance of the specific task.
When fitting a permanent support within an existing cavity or solid wall, it’s not possible to plan a task correctly or to choose the most suitable variety of equipment without knowing:
1, The materials, mortar mix, build/design, the structural stability, the bond and the weight of the structure.
2, the direction and depth of existing floor/joists, if any.
3, the variety of permanent support, fabrication details and the dimensions; length, depth and width.
4, the finished height/position of the permanent support, compared to the existing joist height.
Choosing the correct size of Acrow prop for the task.
The safe working load of the combined use of the Acrow prop & tongued prop attachment varies, of which depends upon the age and size of the Acrow prop, which pin-hole height is used, how plumb, how tightly fitted and the many variable measurements from the Acrow props central axis to the centre of the wall. To reduce the risk of overloading, the inner tube of an eccentrically loaded Acrow prop should not be raised from the outer tube any further than half way.
Recommended Acrow prop Size to height ratio when using the Pro-Tector & standard sized 215mm Tongued attachment
Size 0; Working Height from solid base, 1,280mm to 1,540mm
Size 1; Working Height from solid base, 1,825mm to 2,575mm
Size 2; Working Height from solid base, 1,975mm to 2,685mm
Size 3; Working Height from solid base, 2,485mm to 3,185mm
Size 4; Working Height from solid base 3,190mm to 3.600mm
Raising the collar of an Acrow prop with an anti-clockwise 360-degree turn, increases the height by approximately 8mm; overtightening increases the risk of overloading as the measurement from the underside of wall to solid base will not change; only the inner tube of the Acrow prop and/or attachment will distort. The tongue should remain level at all times to ensure it is capable of supporting the weight of the load correctly.
The Pro-Tector is supplied with m12 x 35mm, Hi-tensile set screws, if lost or damaged, replace with a minimum of 8.8 Hi-tensile. If in doubt please contact us to purchase replacements. To keep the Pro-Tector in good working condition, keep indoors when not in use and clean with a damp cloth and dry after every use.
Please read our propping guide via our website for further guidance on the many different task scenarios. As verbal instructions are inadequate; when any of our products are sold, hired or borrowed, please ensure to provide copies of the written instructions, available to print/download via our website.