THE COSTS OF THE INDUSTRY’S SILO MENTALITY

February 24 2021

The need for greater collaboration across construction sector projects has been a big talking point over the past few years. At the Construction Leaders’ Summit in late 2020, Dame Judith Hackitt lambasted the industry’s adversarial attitude and lamented how it has seeped into construction’s veins. Dame Judith also highlighted the sector’s complexityand its need to remove the “silos of self-interest” that are putting a huge dent in collaboration and productivity. As many construction projects’ teams are still heavily discipline-centric, what is the course of action? How may early engagement between associated trades enable the level of collaboration that Dame Judith calls for?

As Dame Judith has mentioned, the competitive nature of the industry has prevented collaboration across various constructional disciplines. We all know processes are incredibly siloed, and this is in part a result of the fact each discipline focuses solely on their specific area, not necessarily accounting for how their part may affect other elements of a project. Many project teams including structural engineers for instance, create innovative designs which from their perspective fit the bill. But have they considered the implications their designs might have on the riser shaft as an example?

On commercial high-rise projects, steel in combination with concrete is strong and relatively cost-effective. Structural steel is used as the structural frame. Metal decking is placed on top and then layered with steel mesh for reinforcement and concrete poured to produce a composite structural floor (slab). The design of steel around the perimeter reinforces and acts as a stop end for concrete around the riser openings in the floor whilst the concrete is poured.

When completing the structural designs for a commercial high-rise, engineers will no doubt ensure the structure meets all the exacting standards with plenty of built-in strength for the unexpected. They will look at imposed loadings across the structure. Engineers will also determine if their structural design provides the maximum floor-to-ceiling height that is practical, taking into account the horizontal routing of the services attached to the underside of the metal deck.

Whilst from an engineer’s perspective the design is complete, they have unwittingly failed to consider the passive fire protection requirements of the steel design that has been produced. A structural engineer’s responsibility shouldn’t end with the structure. Who is supposed to pick-up the added complications during the build process and the reduction in working area for those vital vertical services routed through the riser shafts? What of the passive fire protection measures required? How are the fire protection subcontractors going to deliver to the necessary standards?

Furthermore, they haven’t pinpointed how it interfaces with the riser shaft, which in the event of fire acts like a chimney. The ASFP’s ‘Fire protection for structural steel in buildings’, commonly known as the Yellow Book, is the go-to document for those looking to protect structural steel in buildings. Once the composite slab is created, fire board insulation is wrapped around all the structural steel to assure protection. But what happens when there is a need to fix riser maintenance flooring to the steel edges of the riser openings in the composite slab? Due to the design of the steel boarder, how do you mechanically fix the maintenance floor, as there needs to be fire protection installed to encapsulate the exposed steel boarder to stop heat transfer without compromising the fire boarding? This has now become an onsite conundrum that needs dealing with, as this problem is causing delays, and is increasing costs and risk (see fig 1).

Another problematic issue is the lack of cover over the top of the structural steel beam during the design of the composite deck intersection of the riser openings. In many cases, the design team seeks to address restricted openings by reducing the cover of the concrete/composite deck. Whilst this deals with one problem, it causes several others including working at height. There needs to be a minimum of 50mm steel deck and concrete cover past the edge of the structural steel flange at the riser shaft intersection, to allow for fire boarding to encapsulate the structural steel and to abut to the underside of the metal deck. Consequently, this provides full and easy encapsulation of the structural steel with the appropriate fire boarding measures.

Some may argue that it is simply a misalignment issue. Unfortunately, this is an example of unconscious discipline-centric thinking. In reality, what’s actually happened is that the structural engineer has not looked at fire incasement because it’s not their responsibility. At present, structural engineers are focused on their design and not the specifics of the riser shafts.

A change is needed

The root of the problem here is the industry’s silo mentality and the blind insistence on designing by discipline, not holistically. Some architects and structural engineers are not aware of the fact they should be designing for the riser shaft maintenance flooring which is critical for the engineers to maintain the services throughout the life of the building. However, in taking a more holistic stance they would be able to see the implications of their designs on the riser shaft zone and fire protection.

One of the ways in which this challenge could be overcome is through engaging the likes of Ambar Kelly at an earlier stage. We need to be brought into the mix at the design stage (RIBA Stage Two) of a project and not during Stage 5 when construction work is underway. Without this change in process and behaviour, the outdated recipe will not yield the end result that is desired. Didn’t a wise man once claim that insanity is doing the same thing over and over again and expecting a different outcome?

See below for RIBA Stage Two diagram.

In order to create better buildings and streamline construction processes, the industry must steadily eliminate its silo mentality. The sector has for too long been preoccupied with breaking down construction works into various disciplines, yet the result of this approach has caused many parties to be only interested in their piece of the jigsaw puzzle. Rarely is there a concern for how it may fit with others. I fear little will change until the industry rids itself of this way of working and takes heed of Dame Judith’s advice.