Bowmer &Kirkland discovers secret of modular on
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4 January, 2017ByCharlieSchouten
•No time towaste
•‘Precise tothe millimetre’
•Plug and playM&E
•Chinese visitchanges perceptions
Contractor hasdiscovered how intense preparation is the key to success on its first modularhotel job in Manchester.
Project:Holiday InnExpress, Manchester Trafford Park
Main contractor:Bowmer &Kirkland
Start date:July 2016
Completion date:May 2017
The constructionindustry has been grappling with the adoption of modular technology for years.
It’s long beendiscussed as one of the ways contractors can get things done faster, safer andat a lower cost – not to mention offering massive improvements to theindustry’s productivity. But as firms consider how best to implement thetechnology, some contractors and clients are already getting to grips willfully modularised buildings.
One such clientis Holiday Inn Express, which has enlisted Bowmer & Kirkland alongsidemodular contractor CIMC to deliver a 220-bed hotel in Manchester. And B&K hasdiscovered that meticulous planning of both technology and trades has been the crucialto success on a project that will be delivered in just 39 weeks.
The 220-bedHoliday Inn Express, which sits a stone’s throw from Manchester’s EventCity andthe Trafford Centre shopping complex, is the first of the client’s ‘generationfour’ range of hotels and is intended to be the firm’s brand standard that it willroll out across the country.
B&K startedon site in July last year on the 39-week programme that has completion pencilledin for 8 May. On the day ofCN’svisit in late November, the progressmade is already remarkable. Installation of the modules, which had only begunat the start of that week, is well under way, with half of the building nearingits six-storey height.
The technologyitself is not brand new to the UK – module contractorCIMC is already working with Robertsonand client Hiltonon two hotels in Aberdeen, albeit with a slightly longer 44-week durationon that project.
The roughlyL-shaped building is having its modules installed in two phases to help keep theprogramme running smoothly and ensure no time is wasted, according to seniorsite manager Gary Lewis.
“The whole thingwith modular is that you seem to get everything at the same time” Gary Lewis,Bowmer & Kirkland. He explains that, to prepare for the installation of themodules, B&K has built a transfer structure up to level one, with noconcrete or steel frame any higher than this point, aside from the two concretestair cores at either end of the building.
No time to waste
Mr Lewis addsthat half of the building goes to its full height, which means follow-on tradescan begin working on the interiors while the other phase of the modules arelifted in – ensuring nobody is sitting idle at any point during the project.
“The whole thingwith modular is that you seem to get everything at the same time,” he says.“Two weeks ago we didn’t have one module installed; now two weeks later we’re releasingcladding, roofing, upper floor corridor works. It’s all about how we then sequencethe follow-on trades to make sure we’re straight into the areas we need to be inwithout any delay.” There are two concrete stair cores at either end of thebuilding.He sayscontractor CIMC, which manufactures the modules in China and installs them onsite, had seen main contractors fail to grasp that concept before, leading toproblems with programmes and ultimately slowing down what are supposed to bequick-fire projects.
“[For example],they’ve installed the modules first and then started to line up trades afterwards,but it can’t happen that quickly unless you’ve made all these plans and arrangementsweeks and months in advance,” he says. “[CIMC] has come with all manners oflessons learned – and I’d be silly not to listen to them.”
‘Precise to themillimetre’
One of these wasto understand that the modules can’t simply be dropped on to the slab withlittle control; B&K had to make sure the modules fitted perfectly toeliminate any problems when it came to lifting and bolting them into place.
“All the work isactually in that transfer slab,” Mr Lewis explains. The team had to cast modulereceiver plates – onto which the modules are bolted – as part of the building’stransfer slab. To do this, B&K boxed out 109 locations on the slab wherethe receiver plates were going to be positioned and cast the slab with aprotective covering of insulation at each position.
Mr Lewis says hewanted them to be “precise to the millimetre”. “CIMC has seen these receiverplates floated in like a standard holding down bolt and it’s a recipe fordisaster.”
Once the slabstarted to cure, the insulation – which marks out exactly where there receiverplates need to be cast – was removed, providing an accurate outline for the moduleinstallation, rather than them being fitted freehand. This was important as thetolerance on depth is plus zero and minus 5 mm.
“Trying to havethat control while casting a full slab – things can easily get knocked,” he says.“You’ll do a survey a few days later and all of a sudden you’ll have to breakstuff out and reset it because things aren’t in the right place.”
Once thesereceiver plates are cast in place, CIMC then welds a series of plates on top ineach corner – meaning that when the modules are lifted in, they fit perfectly.
Plug and playM&E
During themodule installation, the team had a target of eight per day, with modules comingthrough the site entrance to be crane-lifted within 10 minutes and fully fixed withinthe next 10.
“You can’t comealong to the face of the modules and fix brackets anywhere” Gary Lewis, Bowmer& Kirkland.
Each modulecontains two rooms and a portion of corridor, with each room fully finished inside,including carpets, wallpaper, decorations and bathrooms. Mr Lewis describes theM&E works as “essentially plug and play”, with all cabling and pipeworkbrought into a riser in the corridor. This means no M&E work has to be donein the rooms themselves.
The corridorsection includes a floor layer of CFC chipboard, with the ceilings coming withone layer of sealed fire boarding. The only minor works that have be addressedis when two modules adjoin, with a strip of around 120 mm of CFC floor that hasto be installed by hand, while the same applies to the plasterboard.
“The corridor isjust like any traditional [one] thereafter,” Mr Lewis explains. “We still haveto install a second layer of plasterboard and put up all the M&E servicesthrough the ceiling void space. [Then we] plaster the walls, as well all yourusual finishes joinery, floor finishing and so on. In terms of the upperfloors, it’s only the corridors where we have to do any real fit-out, or wherewe have any real M&E.”
Chinese visitchanges perceptions
Mr Lewis isworking on both on his first modular project and his first job for Bowmer&Kirkland after eight years at Galliford Try, and he’s clearly impressedwith the quality of finish in both the rooms and the corridor.
“Maybe I had apreconceived idea that [the modules] would not be quite to the same standard asyou’d get here, but actually, it’s in a controlled factory environment,” he says.
A trip to Chinato see CIMC’s facilities was what changed preconceptions, with the contractorhaving its module construction “down to a fine art”.“[CIMC] had full QAcontrol, things were being done in the correct sequence, and the qualitystandards in every element of the fit-out and the M&E installation was justas good as anything I’ve seen here, if not better,” he says. “We were given atour of the factory and the facility – basically a production line startingwith a steel shell, followed by various stages of fit-out in different areas ofthe facility. It was clean, tidy and well controlled – and sequenced in theright way.”
Once the modulesare installed, the team also has to fully clad the building and get roofingworks under way. B&K has taken a similar approach to this as to the module installation,with precise measurements and accurate sequencing needed to keep the programmeon schedule.
“You can’t comealong to the face of the modules and fix brackets anywhere,” Mr Lewis pointsout. “There’s a real risk if you drill through where you’re not supposed to,you’re going to drill through a bedroom.”
Each module hasa permitted fixing zone at the top and bottom, marked with a substantial pieceof steel.
To install thecladding, the team first fixes a series of 3 m vertical brackets in the permittedfixing zones, which span from the top to the bottom of each module, with the processrepeated across any given facade. This is followed by insulation, horizontal steel,and finally cladding bolts and the cladding itself.
To install thecladding, the team first fixes a series of 3 m vertical brackets “You can’tjust fix anywhere,” Mr Lewis says. “You have to come up with a viable solutionthat really doesn’t compromise fixing through a finished hotel module.”
A similarprocess applies to the roof level, where B&K is using a timber baton roof, followedby a plywood roof deck. The steel parapets will also be fitted in permittedfixing zones to make sure the installation goes smoothly, without any risk ofwater damage to the rooms below.
AsConstructionNewsleaves the site, another module was waiting outside the gates – testamentto the speed of the build and how meticulous pre-planning is crucial to making modularconstruction work, rather than just expecting it to fit together first time.
Mr Lewis saysthis approach has effectively halved the project’s build time from 18 to ninemonths. The team is now focusing on the ground floor and stair core fit-out andthe furniture, fixtures and equipment works – all of which are being built andinstalled traditionally – ready for the handover date on 8 May.
“Everything, allthe way down to knives, forks and spoons [needs to be ready] to make sure theycan open the doors and start using it as an operational hotel,” Mr Lewis says.
“The back end ofthe job is where all the pressures are to come.” But with the modular stageprogressing well and the project’s plan being executed smoothly so far, B&Kappears up for the challenge.