Door Industry Journal - Spring 2018

industry news SALUTARY TALES A regular column, which concisely outlines Door and Gate related incidents, some of which became court cases, brought to you by John Boydell, a Door Industry Consultant and Forensic Engineer since 1984. LARGE ROLLING SHUTTER FALLING INCIDENT, REPORTABLE “NEAR MISS”. The building in question was a post-WW2 concrete portal frame building, over 50 years old, with brick/block-work infill to the gable end, incorporating a doorway opening 5700 high x 5700 wide, with a reinforced concrete lintel over. The masonry above the lintel was 250 mm thick, comprising an outer skin of brickwork (which later turned out to be of dubious provenance) and an inner skin of concrete blocks. An order was placed for a powered shutter to be fitted, maximising the available opening without disturbing internal ductwork, so the shutter was fitted to the outer face of the gable end, installation being completed approx. six months later. A powered 3 inch lath steel shutter was fitted to the outer face by means of multiple 10mm dia. x 70mm long Rawlbolt type expansion fittings through double 100 x 60mm angles welded onto the shutter end-plates. The supporting bolts only penetrated just over 60mm into the outer skin of brickwork. The incident occurred two years after installation, only minutes after some employees had been standing in the doorway under the raised shutter. Viewed from outside, (VFOS), the left-hand bolts pulled out of the brickwork, causing that end to twist, anticlockwise, downwards, wrenching the right-hand fixings out of the brickwork as the whole assembly fell to the ground, just where the employees had been standing. Bearing in mind that a conventional shutter end-plate is continually tending to rotate downwards, theoretically pivoting about the lower fixings, door engineers should always try to have fixing bolts in shear or positive tension fixings in place. If total reliance is to be placed on expansion fittings alone, care must be taken in calculating pull-out loads, checking the engineering capability of the masonry and the tensile strength of the fixing. In the author’s experience, failure of a fixing bolt in tension is extremely rare; failure usually occurs due to “pull-out” of the fixing or fragmentation of masonry. This incident could have been averted if the fix had utilised bolts through the masonry, backing plates on the inside, and compression spacer tubes to avoid crushing of the masonry.

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P C Henderson release new product focus videos Sliding and folding door hardware manufacturer, P C Henderson, is pleased to launch a new series of product focus videos to help our customers gain a better understanding of our products and their key features. The first video in the series focuses on Evolve, P C Henderson’s new and improved automated sliding door system. Presented by Philip Jones, UK Business Development Manager, the video provides a step by step guide to the product including kit contents, features and benefits, specification and available accessories. Stephanie Lee, Digital Communications Manager at P C Henderson is responsible for the creation and distribution of the videos, she comments: “We will be creating videos for all of our future product launches to enable our customers to see our products first hand. Distributors may also find the videos a useful as a training tool to help teams gain a further understanding of target markets and how the products sit within our range. The videos have been designed to quickly inform our customers about our products and features in an easy to follow format”. P C Henderson’s series of product videos and installation videos can be found at www.pchenderson.com and are available for customers to use on their own websites. For further information please email hello@pchenderson.com

J Boydell

John Boydell Email: jmbgpc@tiscali.co.uk Phone: 01952 432429

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THE door industry journal spring 2018