Construction Technology Flashcards
What are the pros & cons of steel and timber frames?
Steel Frame Pros:
High strength-to-weight ratio, suitable for taller buildings.
Prefabricated components enable faster on-site assembly.
Flexibility in design (long spans and open-plan spaces).
Recyclable and durable.
Steel Frame Cons:
Susceptible to corrosion if not protected.
Requires fire protection (e.g., intumescent paint).
Higher embodied carbon compared to timber.
Timber Frame Pros:
Sustainable (renewable resource, lower embodied carbon).
Lightweight and fast to erect.
Good thermal properties, contributing to energy efficiency.
Timber Frame Cons:
Limited structural span compared to steel.
Vulnerable to moisture and pests without treatment.
Fire performance considerations (though mitigated with modern design).
Pros of steel: high strength-to-weight ratio, fire resistance. Cons of steel: susceptible to corrosion. Pros of timber: renewable resource, aesthetic appeal. Cons of timber: less durable than steel.
When would you use a steel frame?
For commercial buildings, such as offices or warehouses, where large column-free spaces or long spans are required.
Multi-storey buildings, where lightweight and high structural capacity is beneficial.
Projects with fast-track programmes, as steel frames are prefabricated and erected quickly.
When would you use a timber frame?
For low-rise residential developments.
Sustainable or eco-housing projects, due to timber’s environmental credentials.
Speed-sensitive projects where lightweight materials reduce foundation requirements and accelerate construction (e.g., offsite manufactured panels).
How would you measure steel and concrete frame?
Steel frame: Measured by weight (tonnes) in accordance with NRM2 or structural drawings. Pricing includes supply, fabrication, erection, and protection (e.g., fireproofing).
Concrete frame: Measured by cubic metres (m³) based on concrete volume for elements such as columns, beams, and slabs. Reinforcement is typically measured separately in tonnes. Formwork & blinding in m2.
What is the process of underpinning?
Underpinning strengthens and stabilises existing foundations. The process typically involves:
Excavating beneath the existing foundation.
Installing reinforced concrete pads or beams to transfer loads to deeper, more stable soil strata.
Sequencing the works in bays to maintain structural stability. Typically 1m bays
Other methods include mini-piled underpinning or mass concrete underpinning.
Why is underpinning used?
To address subsidence or unstable ground.
When adjacent excavations (e.g., for new basements) undermine existing structures.
To allow for increased loadings on existing buildings (e.g., adding storeys).
To stabilise heritage or listed buildings during nearby work
What is the RIBA Plan of Works?
The RIBA Plan of Work is a framework that outlines key stages in the lifecycle of a construction project. It guides the development from concept to completion and operation, ensuring standardisation across the industry.
What are the RIBA stages?
Stage 0: Strategic Definition.
Stage 1: Preparation and Brief.
Stage 2: Concept Design.
Stage 3: Spatial Coordination (formerly Developed Design).
Stage 4: Technical Design.
Stage 5: Manufacturing and Construction.
Stage 6: Handover and Close Out.
Stage 7: In Use.
What forms of construction are you aware of?
Forms of construction include traditional, modular, prefabricated, and sustainable construction.
What current challenges is Covid and/or Brexit bringing to Construction Technology?
Material shortages (e.g., timber, steel, MEP equipment) due to supply chain disruptions.
Labour shortages particularly for skilled trades, driven by Brexit.
Increased costs and price volatility for construction materials.
Programme delays linked to logistic disruptions and import/export regulations.
A shift towards offsite and modular construction to mitigate site-based labour shortages and maintain productivity during social distancing restrictions.
What is a retained façade?
A retained façade is a structural approach where the external façade of an existing building is preserved and supported while the internal structure is demolished and redeveloped. This is often done to preserve architectural heritage or meet planning conditions.
How was the façade retained?
For Brecknock Road, the façade was retained using a temporary propping system designed by a specialist Temporary Works Designer. The system involved:
Installing steel frames and props anchored to the ground and façade to prevent movement or collapse.
Phased sequencing of demolition works to ensure the stability of the retained façade at all times.
Regular structural inspections as the new internal structure progressed.
When did you notice the temporary works weren’t as supportive?
The retained facade was 75% done as a seperate project, which was put on hold. The remaining 25% was from the 1st floor and below. I was then appointed to carry out the project which involved a PTE. As part of the PTE i undertook a site visit which is when I noticed the temporary works weren’t supportive from a visual view.
How did you monitor this risk?
I classified the retained façade as a high-risk item within the risk register.
I worked closely with the structural engineer and Temporary Works Designer to introduce additional inspections and monitoring (e.g., surveys and deflection checks).
I proactively updated the contingency within the cost plan to reflect this risk.
As construction progressed and internal walls, steelwork, and floors were installed, I regularly reassessed the risk, ultimately reducing it as the new structure provided additional stability to the façade.
What are high acoustic ratings?
45-50 Rw dB might be standard for partitions.
60+ Rw dB would be considered high performance, suitable for spaces like high-end offices, apartments, or auditoriums.
What were the acoustic requirements for this project?
The client for LUX 22 required:
High acoustic separation between office areas and adjoining rooms.
Specific Rw dB ratings for glazed partitions and plasterboard walls, typically between 50-55 Rw dB, to ensure confidentiality and comfort.
The use of acoustic barriers within partitions, ceilings, and at junctions
How did you advise the client of these costs?
I attended design team meetings to understand the acoustic specifications and prepared a cost breakdown comparing:
Glazed acoustic partitions.
Acoustic plasterboard partitions.
Acoustic barriers
I explained the cost uplift associated with each option relative to standard partitions, enabling the client to make an informed decision based on budget and performance needs.
Whats the rate of a glazed partition?
For high-spec acoustic glazed partitions (Rw 45-50 dB rating), typical rates range from £450 - £600/m², depending on system type (e.g., double glazed, fire-rated)
Whats the rate of an acoustic plasterboard partition?
£90 - £150/m
