Ceilings are a superhighway for a maze of building services and, with so many trades working in a confined area at height, it’s a pinch point in the construction sequence. Steve Menary finds out how programming and co-ordination remain critical elements.
A labyrinth of ducts and cable trays with wires splayed out across the concrete soffit above where a ceiling is scheduled to be installed is the bane of many specialist contractors. That the problem remains so common illustrates one of the main issues in the way of a successful ceiling installation: lack of sequencing.
“Sequencing makes or breaks a suspended ceiling,” says Robert Barker, membership manager at AIS FPDC and previously a ceiling
specialist. “Cost programmes keep projects compressed and sometimes it’s not possible to do the work in that period. That
then impacts on other trades and health and safety.”
Tradesmen struggling through metal grids, pipes, ductwork and a thick web of wiring can struggle to find the soffit to position anchors for suspension systems on the correct centres without injuring themselves.
“In new buildings, they are trying to run so many services through the ceiling space that when a ceiling contractor gets to work it’s very crowded and hard to safely get to the soffit without cutting yourself,” says Richard Blain, interior finishing trade manager at Hilti.
The ceiling products supplied to contractors generally include advice on the optimum depth that the ceiling should be installed from the soffit to ensure the acoustic performance of the ceiling is achieved on site. A 2010 AIS survey on ceiling collapses
identified ‘insufficient fixings’ and ‘failure to follow manufacturers’ guidance/instructions’ as two of the top 10 reasons behind a ceiling collapse. Recommendations on the selection and installation of top fixings for ceilings are contained in the best practice guide, which is downloadable for free.
Mandeep Bansal, technical manager at Knauf Drywall says: “Contractors don’t always use the right type of fixing. With the metal components, when they form a grid if you miss a cross junction; because a pipe, cable tray or duct is in the way, it would then be less structurally sound.
“It’s important that the architect, specialist contractor and M&E contractor work together. The key is collaboration.”
Mr Blain adds: “We’ve seen situations where the ceiling has gone in then datacomms people come in too late and they can’t get to the soffit at all so they start clipping wires to the ceiling, leading to the risk of a partial or complete collapse, and it collapses.”
Specialist ceiling contractors often bear the brunt of these sequencing problems. Few are optimistic that greater collaboration throughout the supply chain is happening.
“Helping us with sequencing and co-ordination? Forget it,” says Chris Dulley, managing director of specialist contractor DCP, who finds fewer problems in standardised systems.
“Tiled systems are less of a problem as we can often install the grid work, service tiles and perimeter cut tiles, meaning we only spend minimal time installing full tiles once services are installed and commissioned. This of course allows following trades to complete their works without interruption.
“However, when you have drywall ceilings, the grid is less than half of the whole system and means that the boarding and finishing, whether skimmed, taped and jointed, sprayed still takes a lot of time and causes mess. This of course means that any finishing trades have to wait before they can install their products or protect their work, which is of course costly. It nearly always boils down to M&E installations as we inevitably get held up after first-fixing walls and ceilings.”
One solution that has long been mooted as a solution to sequencing problems in all areas of construction and not just ceilings is a greater use of building information modelling (BIM) but Andrew Smith, the managing director of ceilings supplier OWA, remains sceptical.
“BIM is being talked about a lot, but I’m not sure about who’s using it,” says Mr Smith.
“A BIM model would be a model of the whole building but with architects you are lucky if you get a 2D drawing showing the services and the relationship with hanger positions, let alone a 3D one. Some commentators say that it’s the future, but there is a lot of cynicism around the subject.”
Robert Barker argues that greater collaboration is too simplistic and that earlier interaction in the supply chain and a realistic approach before key decisions are made is the key solution.
He says: “BIM will help but buildings have been built for hundreds of years without BIM. The key is speaking to people at an earlier stage and putting together something that’s realistic. It might be that the main contractor says they want a certain type of ceiling that isn’t standard size and needs to be specially made.
“Main contractors, specialist contractors and suppliers need to be invited at an earlier stage. The suppliers need to be there too. It’s not a chain that main contractors are dangling with everyone else at the bottom.”