Fast Effective Fixings Maximise Off-Site Benefits
A major new hospital project is using Spit Tapcon concrete screws and Spit Pulsa 700E cordless nailers to get the maximum benefit from off-site construction methods. The £338 million PFI project for St Helens and Knowsley Teaching Hospitals NHS Trust has seen the new St Helens Hospital completed and the new Whiston Hospital on schedule to be finished by 2010.
As part of the fast track approach taken on the project, NG Bailey one of the UK's largest building services providers, is supplying all the mechanical and electrical services as pre-completed modules through its specialist off-site manufacturing facility, Bailey Off-Site. The modules are then being fixed in place on site using Spit Tapcon concrete screws and Spit Pulsa 700E products.
Around six thousand modules have been installed so far, including about 1,800 primary modules that form the main spine of the electrical and mechanical systems along the corridors of the hospitals, together with around 4,000 secondary modules that branch off them. The modules carry a variety of services including electrical wiring, medical gases, hot and cold water and ventilation ductwork.
The primary modules can be as long as six metres and weighing from 200kg, to as heavy as 600kg. These are fixed using M8 and M10 Tapcon threaded rod hangers, with around 12 fixings per linear metre.
On this type of application Tapcon threaded rod hangers can cut installation times in half compared to conventional drop-in or chemical anchors. The screws cut their own threads in concrete and masonry – which means smaller holes and dramatically reduced drilling times. Insertion and tightening of the anchor is completed in just one quick operation. The drilled holes don't need to be as big as with conventional fixings either – only 6.5mm in diameter and 54mm deep for these rod hangers – so installation is not only quicker, but quieter too.
The Tapcon rod hangers are used for any items that weigh more than around 40kg per linear metre – which accounts for most of the mechanical services. Below that loading, extensive use has been made of Spit Pulsa 700E nailers. These ergonomically designed nailers can be used one-handed with a variety of nails and electrical accessories for different substrates and applications.
On the St Helens site the Spit Pulsa 700E has been used to nail rod hanger fittings to the concrete ceiling. Suspension cables are then fitted to these to support the electrical modules. Because there is no need to drill and screw, this is a very quick and cost-effective solution.
Commenting on the project, Gary Beckett, senior buyer for NG Bailey said:
"We saw the use of the Tapcon fixings and Spit Pulsa 700E nailer as a way of getting the maximum benefit from the off-site construction process. If you are getting major time and cost benefits from supplying pre-completed modules you don't want to squander them drilling, dropping in anchors and fixing nuts and bolts."
"With the Spit Pulsa it is simply a case of pulling the trigger and they are in, and the Tapcon rod hangers kept drilling and noise to a minimum – an important consideration at St Helens where at times we were no more than 15 metres away from wards that were still occupied."
