Construction Technology Flashcards
What are the RIBA Plan of Works?
- The RIBA Plan of Works provides a framework for the management and design of building projects.
- This ensures that all information is gathered before moving to a new stage avoiding costly errors.
Stage 0: Strategic Definition.
Stage 1: Preparation & Brief.
Stage 2: Concept Design.
Stage 3: Spatial Coordination
Stage 4: Technical Design.
Stage 5: Construction.
Stage 6: Handover.
Stage 7: Use of the building.
Can you tell me the different types of structural frame construction you are aware of?
- Concrete frame construction.
- Steel frame construction.
- Timber frame construction.
Concrete Frame: What are the respective benefits in terms of time, cost & quality?
Time:
- When poured in situ this increases time /labour costs.
Cost:
- Relatively consistent price.
- No additional cost for fire safety.
- Ongoing maintenance /repairs increasing lifecycle cost.
Quality:
- Naturally fire resistant.
- Limitations for open spans
- Lacks compressive strength (High compressive strength)
Timber Frame: What are the respective benefits in terms of time, cost & quality?
Time:
- Prefabricated and erected quickly on site.
- Lead in times for off site manufacture.
Cost:
- Generally cheaper than steel /concrete.
Quality:
- Easily adaptable.
- Requires fire protection.
- Vulnerable to decay /termites if not maintained.
Steel Frame: What are the respective benefits in terms of time, cost & quality?
Time
- Quick to assemble (occupied sooner)
- Lengthy lead in times (reliant on foreign imports)
Cost
- Cost of steel can fluctuate.
- Usually cheaper than reinforced concrete
Quality
- Durable / high strength to weight ratio
- Suitable for open plan design
- Corrosion risk if not maintained
- Requires fire protection; intumescent coatings.
Sustainability comparison of structural frame solutions?
- Steel uses high embodied energy for manufacture.
- Concrete often uses locally sourced materials and is 100% recyclable.
- Timber offers greater insulating properties.
- Steel and concrete are both 100% recyclable whilst only 50% of a tree can be used for timber.
- Timber encourages deforestation although it can be argued that this encourages the planting of more trees.
What would you consider when choosing a structural frame solution?
Programme Requirements: Steel /timber quicker to erect on site than concrete.
Clear span requirements
Fire protection requirements: Although steel is not combustible; steel requires protection against heat. Concrete is naturally fire resistant.
Height of the building: Timber framed buildings are restricted in height due to fire protection.
Site logistics: Delivery of prefabricated materials (timber /steel).
Foundation design: Cost of foundations may be considerably more for concrete structures.
What are the different foundation types you are aware of?
- Raft foundation
- Strip foundation
- Pad foundation
- Pile foundation
What is a raft foundation - when would you use this?
- Spreads the load over a large base and reduces the load per m2 of the area.
- Used for lightly loaded buildings on sites with poor soils.
- Heavy loads can cause the raft to move sideways as raft foundations are not very deep.
What is a strip foundation and when would you use this?
- Strip foundations require a continuous excavation to support the perimeter and internal walls.
- Suitable for most subsoils and a light structural design.
What is a pad foundation and when would you use this?
- Pad foundations provide a base for reinforced concrete or steel columns.
- Formed by making an isolated excavation in the shape of a square or rectangle.
- Spreads the load to a layer of bearing soil or rock below.
- They are common on large purpose built structures such as industrial units or other commercial buildings.
What is a pile foundation and when would you use this?
- A series of columns inserted into the ground to transmit the load of a structure to a lower level of subsoil.
- Used where no suitable foundations conditions are present near ground level or if there is a high water table.
What are the different types of pile foundation?
Sheet piles.
- A deep trench is excavated and concrete is poured in situ.
- Can form basement walls or retaining walls.
Bored Piles.
- An auger is used to excavate the soil and then concrete is poured in once complete.
Pre-cast piles.
- Piles are and hammered into the ground.
- Often favoured due to the high noise levels associated with installation.
Why is it important to obtain planning permission and building regulations?
- Breach of law.
- Could be issued an enforcement notice to remove /alter the works.
- Non-compliance with planning: The LA have the power to undertake the work themselves and recover the costs.
- Non-compliance with Building regs can lead to a fine /imprisonment.
What is the Town & Country planning Act 1990?
Regulates development for the future of towns, cities and the countryside.
What are the Building Regulations and why are these important?
Regulates building work for new and altered buildings:
- Safety
- Accessible
- Environmental considerations.
What are British Standards?
- Publications by British Standards Institution (BS)
- Recommendations on minimum standards for materials, design, and construction practices.
What are International Standards?
- Publications by International Organisation for Standardisation (ISO)
- Compatible with and compliment British Standards.
The Avenue, Hull: How did the occupants need for wheelchair access influence your planning and decision process?
All the areas were designed to ensure accessibility for wheelchair users.
This included accessible and doorways, corridors, and turning spaces were wide enough.
The Avenue, Hull: Can you give more detail on how you used Doc M on this project?
Approved Document M provides guidance on how to meet the accessibility requirements of the Building Regulations.
I used it to ensure all elements of the refurbishment design were accessible, including doorway widths and ramp gradients.
The Avenue; What steps did you take to ensure compliance?
To ensure compliance with Approved Document M, every design decision was reviewed with this document.
Also, a building control officer was hired to inspect the work at key stages.
How did you determine the correct clear opening width of accessible doors?
The clear opening width of the accessible doors was determined based on the regulations stipulated in Approved Document M.
It states that there should be a minimum clear opening width of 850mm for wheelchair access.
What considerations did you have for entrance threshold requirements?
To ensure they were flush with the door to prevent tripping or difficulty manoeuvring wheelchairs over it.
I specified Doc M compliant thresholds and looked into the materials that would work best in making them not only functional but also aesthetically pleasing.
How did you design and construct the ramps to all external doors, while ensuring the suitable gradience was maintained?
I used CAD to design the ramps to all external doors, taking into account the gradient needed for safe use by a wheelchair user.
Building Regulation’s Approved Document M was also consulted to ensure ramps were of a suitable gradient (1:15 – 1:20).
The Avenue, Hull: What challenges did you face during the project?
The biggest challenge was ensuring that all designs met the Building Regulations Part M standards.
I overcame this by cross-checking all my designs with the guidelines provided in Approved Document M.
The project did require unique solutions, such as installing ramps for wheelchair access, modifying kitchen layouts to be more accessible, and including accessible washrooms.
I also had to ensure that all doors were wide enough to permit a wheelchair to pass through.
The Avenue, What else did you consider when widening the doorways?
- The structure of the building where doorways required widening to loadbearing walls.
- I appointed a Structural Engineer to determine the walls load capacity.
- S.E then designed the lintels.
Should it not be in a surveyors level of competence to specify lintels?
The structure of the building was being altered and therefore outside my level of expertise to determine the walls load bearing capacity.
What bearing is required for lintels?
- Typically, a minimum of 150mm at either end.
- Span of less than 1.2m this may be reduced to 100mm.
- This can vary so I would check the manufacturers recommendations on all occasions.
What is Doc M of the building regulations?
Access to and the use of buildings.
What parts of Doc M did you include at Cherry Meadows?
Approved Doc M: Vol 1 – Dwellings
Section 3 – wheelchair user dwellings.
What other sections are in Doc M, Volume 1?
- Section 1: Visitable dwellings.
- Section 2: Accessible and adaptable dwellings.
- Section 3: Wheelchair user dwellings.
Section 1 is mandatory for all new dwellings unless one of the optional requirements in section 2 or 3 applies.
The Avenue, Hull - What were the clear opening width requirements?
Visitable Dwellings: 775mm
Accessible Dwellings: 850mm
Wheelchair User Dwellings: 850mm
Section 1 & 2 can vary dependent on clear passageway width – I would take this into consideration.
How would you measure the clear width opening of a door?
From the inside face of the door when open to the inside edge of the door frame.
What are the entrance threshold requirements under Doc M?
That the threshold is an accessible threshold.
How do you measure the gradient of a ramp?
Dividing the rise by the overall length.
What gradient of ramps are required in Doc M?
Gradient between 1:20 – 1:15
- Maximum lengths listed in Diagram 3.1 of Doc M (3)
- Clear width of 1.2m (of any door)
- Top and bottom landings must be provided.
What requirements are there for approach routes?
- Step-free approach: Level, gently sloping or ramped.
- Minimum clear width of 1.2m.
- Suitable ground surface.
- Illuminated. (dusk /dawn timers or motion sensored).
Height of light switches for a wheelchair user?
Between 900mm – 1.1m for ease of location /reach.
Wheelchair accessible sanitary fittings requirement (M3)?
- Wheelchair accessible basins /sinks should be wall hung.
- Typically, the sink rim would be 770-850mm above finished floor level.
- Level Access Shower Trays.
Eastbank: What was the purpose of your inspection?
This was a progress meeting for ongoing refurbishment works.
During the meeting I identified a gap to the kitchen fire door threshold where the thickness of floor covering had changed.
What type of property did you inspect in Lytham?
Residential supported living accomodation.
Large victorian building, cavity wall construction and suspended timber floor.
Eastbank; Why had the threshold gap of the kitchen fire door increased?
The threshold gap of the kitchen fire door increased due to a change in the floor covering, which was replaced with a thinner material (vinyl) than the original (tiled floor).
Eastbank; What tool did you use to measure the gap of the fire door?
I used a door gap gauge to accurately measure the increased gap of the fire door.
Eastbank; What standards did you refer to identify the requirements of fire door threshold gaps?
I referred to the guidelines provided by BS 8214: CoP for fire door assemblies (timber)
Note: BS 9999 (2017 Fire safety standard) states that threshold gaps for timber doors should be in accordance with BS 8214.
Eastbank; Who did you consult with about the increased threshold gap?
I consulted with the clients designated Fire Safety Engineer about the increased threshold gap.
Eastbank; What was your proposed solution for resolving the issue?
My proposed solution was to provide a surface-mounted drop-down seal to accommodate the gap between the door and threshold.
Eastbank; What were the recommendations given by the fire engineer?
The fire engineer recommended an integral drop-down seal as they would not accept surface mounted.
Eastbank; Who did you instruct to undertake the necessary remedial work?
I instructed the contractor to undertake the necessary remedial work which was subsequently signed off by the clients fire engineer.
Eastbank; What exactly was the remedial work that had to be done?
Installation of an integral drop down seal.
Eastbank; Was the change of floor covering approved in the design stage?
Yes; a Provisional Sum was included to allow for alterations to all internal doors following the installation of new floor coverings.
Eastbank; what were the threshold requirements identified in BS 8214?
Threshold gaps for fire performance and smoke control should not exceed 3mm at any point.
If not an FD30s (not requiring smoke control) the threshold gap should not exceed 8mm.
What is a drop down seal? How do these work?
Drop down seal is a device fitted at the base of the door to stop smoke and fire from passing through the gap between the door and the threshold.
It works through an automatic mechanism where the seal drops down when the door is closed and retracts back (up into the door) when the door is open.
What is an FD30?
Fire door able to resist integrity failure for 30 min.
44mm thick.
What is an FD60?
Fire door able to resist integrity failure for 60 min.
54mm thick.
What checks would you do to ensure a fire door is compliant?
Look for the certification:
Fire door manufacturers mark their doors.
Intumescent seals:
Seals should be fitted around the door or frame.
Check gaps:
If the gap between the door and the frame is between 2mm and 4mm all the way around.
Hinges:
Fire doors should be fitted with at least 3 hinges. The hinges should be CE marked and fire rated to the same standards as the door.
Fire door closure:
It is essential that a fire door ‘latches shut’ when closing.
Fire Door is Clearly Marked:
All fire doors should have clear signage fitted.
How could you tell the difference between an FD30 and FD60?
Thickness of the door.
FD30: 44mm
FD60: 54mm
Winckley Square: What factors did you consider when choosing to recommend the installation of dormers?
- Durability and low maintenance costs of uPVC windows.
- The excellent insulation qualities of timber frames
- The aesthetic appeal of dormers in enhancing the overall building design.
Winckley Sq: Can you explain how you used Part L during your design process?
This guided my decisions on:
- Insulation
- Efficient energy use
- Appropriate glazing