Construction Technology & Environment L2 & L3 Flashcards
What are the requirements and considerations of an accessible WC?
- Contrasting colours
- Unisex
- Provide at least 1 in each area that is accessible
- Be able to wash and dry hands whilst seated
- Provide support rails
- Provide a pull cord
- 2200x1500mm room with turning circle
- Outwards opening door
What is a critical dimension?
A measurement made that distinctively positions something so components go together in accepted tolerances.
What construction details did you choose for the office and why?
Blockwork with timber lid with fire boarding. This was chosen for fire regulations to reach requirements and provided construction that is robust with potential risks of forklifts.
What is the different roof constructions you can use? What are the advantages and disadvantages?
- Cold (Insulation below deck): ADVS - Cheap, allows construction where restricted height, easy to construct. DISADVS: More movement to deck and covering, ventilation required.
- Warm (insulation above deck): ADVS - resists movement, tapered insulation, upgrade possible. DISADV - Potential damage from walking, membrane exposed.
- Inverted (Insulation above membrane): ADVS - Ease of replacing and upgrading, protects deck. DISADVS - Expensive, potential insulation deterioration, difficult to detect leaks.
What defects find associated with inverted roof?
- Trapped water through construction causing blisters to the deck.
How would you find a leak?
Use tracing through heat detection of the deck, although costly in this case beneficial as expected not.
What were the remedial works to the inverted roof deck?
I noted that the lead had split, or even been removed from areas of the roof, I specified a code 5 lead to be reinstated around the perimeter and the waterproof membrane is to be patched up to and underneath the flashings.
What is a u-value? What are the current u-value guidance in the Approved Documents L2B?
A U-value is a sum of the thermal resistances of the layers that make up an entire building element.
Pitched roof - 0.16
Flat roof - 0.18
Wall - 0.26
Window - 1.6
What issues can you have walls with increasing further weight to the roof?
Roof spread with the additional loadings were possible. Requested the Structural Engineer review this.
You mention ventilation, why would this be considered on a warm roof?
- This would not be required on the warm roof, as the rafters would be infilled with insulation and further insulation above.
- However, if the contractor was to proceed with a cold roof, they were to be required to allow for 50mm installation within the rafters which was not possible.
You mentioned value engineering between SIPS and Timber frame. Please tell me what value engineering is?
Value can be perceived different to each person. But it involves substitution of a part of the construction process for another that provides same function.
Some value considerations can be time, cost, life cycle, environment factors, ease, quality.
What considerations did you have of the two methods to make your decision?
- Offsite construction allows typically better quality assurance, programme savings, health and safety as controlled environment, costs on labour
- Bespoke nature typically more expensive, not much flexibility, typically require advanced payment
What are the typical construction details of a timber frame to floor construction?
Foundation, DPM / DPC, sole plate to the floor bolted (2x 100mm), uprights of walls with insulation infill, vapour barrier internally with plaster board, external envelope cladding.
Was this the only consideration for value engineering on the frame?
This was a significant element so therefore the cost was substantial on the savings. We further considered internal walls to metal stud rather than fully glazed with built in shutters for privacy.
At what stage in the design did you consider this with regards to RIBA plan of works?
This was completed in the Concept stage. It was decided in the Feasibility stage that it would be timber frame, although considerations were required if SIPS or insulated panel.
