Braced for strong demand

Buoyant growth and a ‘tick-shaped’ curve for recovery is the British Constructional Steelwork Association’s (BCSA) optimistic outlook for 2021: “We are forecasting a 12.1% increase in 2021 and a further 7.1% increase in 2022,” predicts chief executive officer Dr David Moore.

This is even more optimistic than last year’s forecast, when the BCSA was looking forward to a ‘slight boost’ in demand through 2020. Thanks to the Covid-19 pandemic and Brexit (see below) that did not pan out, even though construction escaped lockdown in most of the UK (Scotland allowed work to continue only on ‘essential sites’ until 28th May when other construction sites were allowed to return to work). 

Moore’s forecast for 2021 therefore comes with some substantial caveats about the assumptions that have to be made, such as how long the lockdown will last, whether it will be a long and gradual process or whether there will be a second peak in infections and deaths later in the year. The changes to working practices – such as working from home – will also affect demand and ‘just in time’ deliveries from overseas suppliers will also suffer.

This article was first published in the September 2020 issue of The Construction Index magazine.  Sign up online.

For example, in the commercial office sector, the BCSA predicts a 5.4% fall in 2021 and a further fall 
of 6.2% in 2022 as more people find themselves working from home. That fall in demand is not just for steel, says Moore, but also includes other construction materials such as concrete.

But the BCSA is confident that other sectors will more than make up for this. Warehousing and manufacturing will, for instance, require greater capacity so there will be strong demand in the industrial shed market. “In 2021 we are forecasting a 12.0% rise and a further 12.3% rise in 2022 due to an increase in industrial shed capacity as more manufacturing and storage is moved back to the UK,” Moore says. 

Demand could even exceed these forecasts, he believes, if plans for special port facilities go ahead as these will also need massive storage facilities. “It’s all excellent news for the steel industry because we dominate this market massively – we have 96-97% market share.”

The real boost, though, will come from public sector spending. Health, education, infrastructure – even prisons – feature in the government’s spending plans published in June as The National Infrastructure and Construction Procurement Pipeline 2020/21

Worth between £29bn and £37bn, the procurement pipeline covers 340 individual procurements across 173 projects, with construction work accounting for roughly £19.2bn of the total.

Published by the Infrastructure and Projects Authority (IPA), the report is the first ever to outline spending and procurement for a year at a time (its reports usually cover multi-year pipeline plans). The report was published to provide better pipeline clarity to the industry during the crisis and is seen as a victory for organisations such as the BCSA. 

“We’ve been lobbying government to bring the construction pipeline forward because we’re concerned that private sector clients have been delaying spending decisions,” says Moore. We wanted to see increased spending in Q3 and Q4, with some more carrying on into Q1 of 2021, and I’m pleased to say that seems to be what they’re doing.”

Infrastructure works are an important market for BSCA members, and the pipeline document does not disappoint: the design and build contract for the HS2 station in central Birmingham alone is worth £500m and road-building plans include a £7bn budget for smart motorways. Both of these projects generate a lot of work for steel fabricators.

Analysing these plans, the BCSA forecasts a 7.8% rise in 2021 and a further 9.3% rise in 2022 as the government invests in new and upgraded hospitals, schools and prisons. This includes 28 new-build schemes under the Free School programme, four new-build schemes under the Priority School Building Programme and two new prisons at Glen Parva and Wellingborough.

“This is a boost in public sector spending so you can see that once we get through Covid and lockdown the industry’s prospects are excellent,” says Moore. 

David Moore bio

Dr David Moore is relatively new to his post as chief executive of the BCSA (he replaced Sarah McCann-Bartlett in December 2019) yet well-qualified to steer the association through the technical challenges that are expected in the immediate future.

Over the next three years more than 30 design guides to steel construction need to be updated or amended as the European codes and standards are comprehensively revised. 

The biggest challenge, though, is Brexit. In the near future Moore and the BCSA will have to negotiate with former EU partners – plus any new markets – over the technical details that will have to underpin any trade deals.

A career technocrat, having spent 23 years with the Building Research Establishment before joining the BCSA 15 years ago, Moore is uniquely qualified for this task.

As the BCSA’s former director of engineering, Moore can now supervise the task of bringing design guides such as the ‘Blue Book’ – Steel Building Design: Data Design – with all the experience that comes from being a member of all the relevant technical committees.

The author of more than 70 peer-reviewed publications and design guides, Moore has contributed to the creation of many of the national and European standards for steel design and construction. 

Consequently, he shouldn’t have much difficulty taking on the CEO’s external roles, particularly that of chairman of the British Standards Institution (BSI) committee responsible for the UK’s input into the development of the steel Eurocodes.

POST-BREXIT STANDARDS

While there are many large projects ready to be commissioned, the economic landscape in which they will be constructed is far from clear, the UK having completed its divorce from the European Union by the time they take place.

“The transition period ends in December and we hope it ends with some kind of trade deal but we don’t know,” says BCSA CEO David Moore. Some consequences, such as the points-based immigration system, will have little effect upon the steelwork industry he believes.

Tariffs, though, may be simpler after January 2021. Since the introduction of UK Global Tariffs in May 2019, tariffs on steel remain at 0% and there are some welcome reductions. Tariffs on structural bolts, for instance, have been cut from 3.7% to 0%, and so-called ‘nuisance tariffs’ – those of less than 2% – have been removed. Tariffs are now organised into bands, so other tariffs have been rounded down to the nearest tariff band. For instance, a tariff of 14.3% might be rounded down to 12%.

Conformity assessments – standards – are a well-documented area of disagreement. The UK government is to introduce an equivalent to the CE marking, the UK Conformity Assessment (UKCA) marking. “Depending on the terms of the deal, it might be that anyone that is CE-marking will then have to get to grips with UKCA marking,” says Moore. “The position for CE markings is that they will be allowed for a limited time after January so that European competitors that are CE-marking can put their goods on the UK market.”

Northern Ireland is another matter. “My understanding is that the UK is trying to create a UK internal market where there is mutual recognition of marks between the four countries: England, Scotland, Wales and Northern Ireland. So, if we have a UKCA-marked product in England, we can put those on the markets of the other three countries and vice-versa”. Until the deal has been negotiated there is no certainty over what will be acceptable, says Moore.

This article was first published in the September 2020 issue of The Construction Index magazine.  Sign up online.

Learning the lessons of Grenfell

A technical document such as the National Structural Steelwork Specification (NSSS) rarely reflects national events but under Dr David Moore’s guidance the 7th Edition is the BCSA’s bid to prevent tragedies such as the Grenfell Tower fire occurring.

“There were issues surrounding the quality of the components of the building, whether they met specification of the designer, whether they were fabricated and erected to the right specification,” explains Moore. “We felt that we at the BCSA should take ownership of the issues that we could control in terms of building design.”

The main item that the BCSA identified is intumescent paint, which Moore says is all too often regarded as decoration. 

“This is not just paintwork, this is fire protection and is actually life-saving, so it has to be done correctly,” he declares.

The latest edition now contains a whole chapter on specifying and applying intumescent coatings correctly, going into details of the correct thickness to achieve the correct fire protection rating. This, he says, is part of the specification universally used throughout the UK and so will be part of the contract between the fabricator and the main contractor. 

“We also want to change the way in which intumescent paints are applied, as this is generally done outside and we have seen a number of instances where these paints are actually beginning to flake off the steel structure,” he says. “We now state that these coatings should be applied in the workshop, an environment that can be controlled so the coatings adhere and perform correctly.”

The provisions also create a new role, Responsible Painting Co-ordinator, that ensures that these specifications are enforced.

The latest edition, which will be mandatory by the end of 2020, also tasks fabricators with having third party certified welding systems.

Reverse VAT

The BCSA has been fighting a rear-guard action against the Treasury introducing reverse VAT, which it says will badly damage its members’ businesses. 

This system would mean that the customer receiving the service has to pay the VAT directly to HM Revenue & Customs instead of paying the supplier. For businesses, reverse VAT cuts cashflow while increasing administration costs.

So far, the BCSA has been successful in lobbying for postponements. Last year the introduction of reverse VAT was postponed from October 2019 until March 2020, when the pandemic provided a good reason to postpone it yet again until March 2021. 

“We’re still lobbying quite hard to have it postponed indefinitely,” says BCSA chief executive David Moore, “that is to say – cancelled. It’s a cashflow issue that is quite significant for a medium-sized company, not just a one-off event.”

Steelwork’s ups & downs

The steelwork industry has coped with recent upheavals remarkably well – but the real test is still to come

As the managing director of Halifax-based Elland Steel Structures, BCSA president Mark Denham has witnessed both Brexit and Covid-19 stop decision makers in their tracks and take a ‘wait and see’ approach before committing to construction programmes.

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“When they’re unsure what’s going on in the market, they stop. So, during the elections and all the uncertainty over Brexit, the orders stopped,” he says. “Market conditions deteriorated around November, December and January. Now, as steelwork fabricators, we were still busy but the gestation period means we feel the effects months later.” 

“It’s been the same with Covid. People in our industry who weren’t busy in March, April and May weren’t hit by Covid – it was other things. Now we’re seeing the market struggling to the end of the year but we do see signs of a lot of work coming to fruition that will keep us busy throughout 2021. It’s the same lag, there’s just a different reason for it.” 

And this time-lag means that the industry is out of step with the rest of the UK economy. While other industries took advantage of the furlough scheme, the construction steel industry was still hard at work fulfilling orders. Now, when the scheme is coming to an end, is when BCSA members need the furlough scheme to keep their staff employed.

Denham’s own company is a typical example. Elland Steel had three large contracts to fulfil that were commissioned back in 2018: Wood Wharf Building 3, part of a 15-storey building in Canary Wharf; Kings Cross S1, a 12-storey office block; and Building 100, The Embankment Manchester – a nine-storey office building in Salford. In total that is nearly 5,000 tonnes of steel worth £15m to Elland.

None of these contracts could be delayed, so through the furlough period Elland’s 45 operatives on the shop floor were still working normally (albeit with extra PPE, social distancing and hand sanitising stations) while 45 office-based staff worked from home.

“For us it was like the phoney war – it didn’t affect us that much. The experience of my company was that the vast majority of our sites were not shut down during February and March,” Denham reports. 

“There was the odd day when sites were shut and obviously measures were taken to mitigate risk and there were issues with hotel accommodation etc., but generally sites carried on running. For these type of sites – and larger – I think our experience was pretty similar to that of  other steelwork contractors. I think it was a little more difficult for smaller sites where some decided to cease activities straight away but they probably re-opened within two to three weeks.”

The challenge now, Denham says, is to persuade the government to modify its ‘one size fits all’ approach and recognise that the construction industry is not like, say, the hospitality industry. There’s no ‘eat out to help out’ equivalent to help maintain cashflow for construction firms.

“We’re lobbying government for an extension to the furlough scheme for construction because now we’re hitting this dip in demand,” Denham argues. “Everyone in construction is affected, whether it’s the concrete guy, the cladding guy or steel: every element in the construction industry is facing the same issue.”

Structural Steel 2020 – the crème de la creme

Now in its 52nd year, the Structural Steel Design Awards (SSDA) demonstrates the versatility of both the material and the UK fabricators. This year’s 22-strong shortlist showcases the engineering nous, ingenuity and imagination of the UK’s construction steel industry. The shortlist also shows how steel is employed throughout the UK and Ireland for an extraordinary range of projects, from attenuating the gale-force winds that beset Leeds’s tallest building to creating a new Dublin landmark in the shape of the Guinness Gravity Bar.

Here are just three examples of the engineering feats that might yet win prizes when the winner is announced in October

Showpiece viaduct completes A14 upgrade

The River Great Ouse viaduct is the showpiece of the six new bridges that Cleveland Bridge has fabricated and constructed for the new A14 trunk road between Cambridge and Huntingdon.

It is colossal. Stretching for half a mile, the viaduct required 6,000 tonnes of steel, comprising 76 separate main girders and 400 cross-girders. The bridge spans the river itself and a large area of floodplain on either side. Most of the main girders required were 40m long, 2m deep and weighed 50 tonnes apiece. 

When it opens to traffic, the viaduct will take the new A14 over the river and the East Coast Mainline Railway. It is part of the new £1.5bn, 19km-long A14 upgrade which was opened to traffic in May, eight months ahead of schedule. 

Some 64 pillars carry the viaduct over the River Ouse floodplain, each of them around 2m wide and embedded up to 30m in the ground. The pillars support the 17 spans of steel beams and concrete slabs that form the bridge deck.

The section of bridge that crosses the river has a longer span, posing a significant challenge for the architects and structural engineers. The solution was to specify more complex girders, with larger, deeper haunches to carry the greater load. 

Cleveland Bridge suggested a different sub-grade of steel for the flanges of these girders, which were in excess of 50mm thick, to avoid the need for layering. This made the haunch girders easier and quicker to fabricate without compromising structural integrity. The girders were re-designed with this change of steel grade in mind, helping to reduce material and fabrication costs. This saved time in the production process, with the added environmental benefit of reducing energy use.

To produce the cross girders more efficiently, Cleveland Bridge devised a new welding procedure. This involved modifying the T- and I-beam machine with two welding heads on each arm, instead of the usual one, allowing twice the amount of weld metal to be placed per metre per minute. This measure improved the efficiency of fabrication significantly.

The haunch girders are 4.2m at the deepest section so they could not be transported vertically and went to site lying on their side. This meant Cleveland Bridge had to devise a method of righting the 93 tonne girders and then lifting them into position once on site. But the company is experienced in this type of challenge having been involved in both the Tyne Bridge and the Sydney Harbour Bridge.

The fabricator designed a bespoke solution, which it called a ‘lifting claw’: a special assembly that clamped around the top flange and, working over a base of protective timber mats, rotated the girder into an upright position as it was lifted.

This article was first published in the September 2020 issue of The Construction Index magazine.  Sign up online.

LSE’s steel exoskeleton

Featuring exposed steelwork, the latest building to be redeveloped by the London School of Economics is architecturally distinguished both in appearance and design. The Central Building Redevelopment (CBR) replaces four buildings yet makes way for a wholly new public square beneath which there is a 200-seater auditorium, a bar and plant rooms.

The site is in central London, where space is at a premium, so the design maximises floor space by slimming down the floor construction and using rectangular hollow section (RHS) or plated floor beams, featuring bottom plates to support the building’s long span precast floor units, which sit within the depth of the beams.

The design’s use of exposed structural steelwork required Billington Structures to engineer bespoke parts and to ensure that most of the steel connections are hidden from view. This was achieved by either using flush connections or positioning the end-plates to create a shadow gap that could then be used as a repeating pattern, so it became an architectural effect. In order to avoid welding on-site, many of the steel members have an internal bolt connection that is concealed behind a hatch.

From ground level, the building consists of two elements: the 13-storey Tower Block and the six-storey Houghton Block. At either end of the blocks, that sit side-by-side for just under half of their lengths, exposed square hollow section (SHS) bracings bookend the project and form another highly visible exposed steelwork element. This exoskeleton bracing, which sits approximately 300mm outside of the building envelope, is an aesthetic element and structural necessity, sharing the stability with two concrete cores. Significant forces are transferred both within and into the SHS bracing system, and so Billington Structures engineered bespoke cruciform node joints with machined flush plates, to ensure the correct standard of finish was achieved.

At ground floor level, encased in concrete, there are two large plate girders measuring 17m long × 1,600mm deep, so big that each one had to be brought to site in two pieces. These are part of the basement construction and so extend beyond the footprint of the building and underneath the public square, to the girders and are designed to carry heavy loads from fire engines in an emergency, and a mobile crane for when the rooftop plant needs to be replaced.

The Tower Building has an atrium formed by exposed steel columns that start at basement level. This atrium provides access to the auditorium and to the Tower’s main staircase, known as the ‘meandering stair’ as it shifts along the structure one bay per floor. The idea of this design is to improve connectivity and collaboration between different departments on different floors.

This staircase is formed with a lightweight prefabricated steel frame and was lifted into position piece by piece along with the main steel frame. 

The result is that the LSE have both a new building and a new public square to add to its amenities. The building itself is at the leading edge of academic architecture and, despite making way for a new square, has an internal floor area of 15,507m2 that is only fractionally less than the four buildings it has replaced.

Waterloo’s small wonder

In terms of steel used, the roof at London’s Waterloo Station is one of the smallest to be shortlisted for the BCSA’s 2020 awards – only 400 tonnes and 15% of that was temporary. Yet it required a great deal of complex design work to meet the brief, which involved retaining two specific views.

 

The roof covers a new concourse filled with shops, bars and restaurants that links the 1990s-built Waterloo International Terminal (WIT) with the original station and fills the gap between the original Victorian-built Waterloo station canopy and the adjacent curved and glazed roof of the WIT structure. 

Network Rail wanted the new roof to shelter commuters while preserving two vistas that are integral to the station’s aesthetic appeal: the Grimshaw-designed WIT arches seen when entering the former Eurostar terminal; and the listed Waterloo station Victory Arch and stairs viewed when leaving the same platforms.

The site imposed its own restrictions on the roof construction because of what lies beneath: Waterloo station’s underground ticket hall and a lot of tunnels. This ruled out any form of piling so the structure for the new roof needed to be light. Steel was the natural choice.

 

The infill roof is a rectangular steel-framed box, tapered along one side to accommodate the shape of the WIT structure and over-sailing the two station roofs. It measures 52m × 18m × 26m high at the western end and 21m high at the eastern end and is supported at either end by a steel-framed and blast-compliant glazed envelope.

Although the eastern gable is supported on Waterloo’s 1840s-built masonry walls the new structure is otherwise self-supporting. It sits within millimetres of both the WIT roof and the adjacent 19th Century-built Waterloo roof, close enough for weather protection but far enough to allow 135mm of movement.

Although the steel is relatively light, the load of 400 tonnes has to borne somewhere and so the team had to calculate whether existing loads could be transferred elsewhere to accommodate the new roof. So, the buffer stops in the WIT were moved 50m down the line to remove any potential train impact from the new roof and free up some load-bearing capacity from the existing structures.

 

These were then reinforced with two 508mm-diameter circular hollow section (CHS) columns to support it in the middle. These CHS columns allow the structure to have a central area with a 26m clear span yet, because no foundations can be installed, the CHS members are founded directly on top of the WIT platform slab using bearings to preserve the roof.

The main span of the roof, its spine, is a 52m-long spine truss that is 4.2m deep and weighs 27 tonnes. It was brought to site in three sections, with the longest element, which spans between the CHS columns, weighing 13.5 tonnes. This central spine truss supports a series of eight pairs of gullwing trusses that sit perpendicular to the main structure and form overhangs on either side. Each wing measures approximately 8.3m long x 4.0m deep.

This article was first published in the September 2020 issue of The Construction Index magazine.  Sign up online.

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