Construction Technology & Enviornmental Services Flashcards
Tell me about the RIBA Plan of Work
RIBA Plan of Work 2020 0 Strategic definition 1 Preparation and brief 2 Concept design 3 Spatial Co-ordination (recently changed) 4 Technical design 5 Construction 6 Hand over 7 use
Generally
0-4 Usually occur one after each other.
5 - Construction and PC achieved
6 -7 Same time usually, defect liability period.
Tell me about soil?
Cohesive and non-cohesive soils.
Cohesive has good load bearing capacity as the particles within the soil bond to one another these tend to include clay, silt etc.
Non-cohesive has poor load bearing capacity as the soils tends not to bond and lays near one another, these tend to include sand, gravel, made up land etc.
Tell me about foundations?
Depends on the bearing capacity of the Soil, usually strip foundations however if the soil is poor then use raft or pile.
Pad used for point loadings.
If the soil is cohesive then use strip.
Raft and pad good for framed buildings
Tell me about Timber frame construction?
Balloon frame (Studs extend to roof rafters) or Platform frame (Studs at each floor level)
Negative image.
Off site (MMC). Quick erection, cheap and sustainable.
In relation to flat roofing, whats the difference between a warm roof, a cold roof and an inverted roof?
Warm roof – insulation above the roof deck. Still need vapour barrier.
Cold roof – insulation under the roof deck. Prone to condensation need vapour barrier.
These should be used when working with finished roof/ceiling heights to achieve requirements/costs/suitability etc.
Inverted roof – insulation is the waterproof covering. Expensive to repair leak.
Used to protect the water proofing layer from UV degradation.
What is MMC? and tell me about it?
Modern Methods of Construction.
Parts or sections of the building are constructed offsite and assembled on site. The aim of MMC is to improve speed, quality, cost and reliability.
MMC sometimes referred to pre-fab, modular or offsite.
What is included in a Site/Soil Investigation?
Gas investigation/monitoring - determines any toxic gasses
Geo-technical information about bearing capacity of soil- allows design of foundations
What is a Deleterious Material?
Material which is hazardous to health or can cause harm to buildings/things.
Tell me about High Alumina Cement and what would you do if discovered?
High Alumina Cement - Banned in 1970s was originally used due to its fast curing time.
However, the strength of concrete significantly decreases with age (around 2/3) and is susceptible to chemical attack (ASR, Chloride or Sulphate attack) when in high temperature or high humidity environments.
Used usually in pre-cast concrete beams, lintels etc.
Refer to BRE guide regarding the assessment if found.
Ensure the property’s temperature and humidity is controlled satisfactory to reduce the likelihood of chemical attack.
Have the installations tested by a Lab to determine content. Appoint SE to determine condition and monitor.
What would you do if you Identified Lead pipework in plumbing?
Lead - If used in the pipework which may contaminate drinking water, remove as it is harmful to health and can cause poisoning.
If in waste pipework it may be ok to leave dependant on condition.
Tell me about Calcium Silicate Brickwork? What would you do upon discovery?
Calcium Silicate Brickwork - Subject to extensive shrinkage and expansion, mortar needs to be flexible. Cracks tend to appear if incorrect mortar used. Shouldn’t be used with other bricks such as clay as differential thermal movement will occur extensively.
Cracks usually wider to the perp, Diagonal cracking can occur.
Determine any cracks, if cracks have occurred extensively which may cause structural failure appoint a SE. May be overcome by re-pointing in a suitable mortar.
What would you do if you discovered Asbestos?
Asbestos - Used in boarding, cladding, insulation, sheets, gaskets, doors etc as good insulator and good fire properties - Airborne fibres if inhaled can lead to asbestosis or lung cancer.
Leave the area and make any persons egressing around the area aware. If instructed advise to instruct a suitably qualified Asbestos Surveyor to determine the content and extent. Air clearance test will be required if disturbed.
What are Mundic Blocks and what would you do upon Discovery?
Mundic Blocks - Used predominantly in South West of England,
Loss of structural integrity when in damp conditions due to the aggregates being attacked by the glue portion of the mundic.
Take a sample of the blocks and have the samples tested by a Lab to determine composition. Following the testing results will return classifying the blocks into categories including Class A1, A2, A3 B and C.
If C will require a SE to determine.
Some insurers wont insure the building.
Tell me about Liquid Waterproofing?
Hot applied systems - used by distributing a seamless system which dries to around 4mm thick.
Cold applied systems - same as above though applied cold instead of hot.
Subject to UV degradation. Use an additive and membrane below.
Quick, easy to detail. Durable, Use an approved installer with life long guarantee. Can be topped up in later years to upkeep guarantee.
Issues with the solvents used cause not pleasant smells and fumes. Can be overcome by using solvent free systems.
Tell me about Aluminium Sash Windows?
Used in Allendale Road
Very worn nowadays, springs defective.
Tell me about Asbestos Corrugated Cement Cladding Sheets?
Risks from fibres, friable surface so never walk without roof boards as may collapse.
What are the risks of No Fines Concrete?
Very low resistance to carbonation which may result in spalling or corrosion to a steel reinforcement. This is because of the voids within the finish.
(Rice krispies)
Tell me about trusses?
Introduced in the mid 1960s to aid the housing sector.
Pre-fabricated in a factory which are pressed together usually with steel fastener plates, though plywood can also be used.
Tell me about wall ties?
Widespread in housing from the 1920s-now.
Tie both pars of cavity wall together used every approximate 900mm height and 450mm centres staggered in accordance with Doc A.
Common types include butterfly, twist and double triangle.
Prior to 1978, wall ties were usually manufactured from galvanised mild steel. BRE suggest the average Zinc loss is 2.1 micros per year which would be an approximate 30-60 year life span of the coating. Following the loss of the coating the wall tie may corrode or fail.
Nowadays they’re made from stainless steel ties.
What are the types of curtain wall system?
Stick system
Unit system
Panelled system
