Demolition & Structural Stability

What is a 'demolition survey' and when is it required?

• AA detailed structural survey before demolition identifying hazards, structural loads, and sequencing before work begins✓
• BSuperfluous, because the structural engineer's drawings for the original building give all of the information that is needed
• CA survey needed only for buildings constructed before 1970, when different structural materials were still in common use
• DOnly by architects

Answer: A demolition survey is a comprehensive assessment identifying structural details, hazardous materials, utilities, and method sequencing to ensure safe demolition planning.

What are the main hazards in demolition work?

• ADemolition is straightforward and hazard-free
• BOnly noise
• CDust on its own, which is fully controlled by damping down the structure with a water bowser before work starts
• DStructural collapse, falling materials, dust (asbestos, silica), noise, manual handling, hazardous substances✓

Answer: Demolition hazards include: unplanned collapse, falls of materials and persons, asbestos and hazardous material exposure, noise, vibration, dust, and struck-by incidents.

What must a 'method statement' for demolition include?

• AOnly the budget agreed with the client and the dates on which each part of the building is due to come down
• BOnly timescales
• CSequencing, hazard controls, plant equipment, site layout, waste management, and responsible persons✓
• DOnly the address of the building and the name of the demolition contractor appointed by the client for the works

Answer: A demolition method statement details: the sequence of operations, hazards and controls, equipment to be used, site layout, utilities management, waste procedures, and personnel responsibilities.

What is 'structural stability' in the context of demolition?

• AA matter for the demolition contractor's insurers, who inspect the structure before the work is allowed to begin
• BA matter for the structural engineer alone, who confirms stability in writing before the contractor arrives on site
• CA consideration only for buildings over four storeys, as smaller structures collapse in a predictable way
• DEnsuring structures remain stable during demolition through proper sequencing, propping, and monitoring✓

Answer: Structural stability during demolition requires careful planning to prevent unplanned collapse. This involves proper sequencing, temporary propping if needed, and monitoring of remaining structures.

What is a 'temporary works' design in demolition?

• AA matter of common sense for the site foreman, who can arrange propping using materials already stored on the site
• BSomething that can be omitted where the demolition is carried out from the top downwards using hand-held tools only
• CA design needed only for new construction, since an existing structure already has permanent support in place
• DEngineering design for temporary structures (shoring, bracing, debris containment) needed during demolition✓

Answer: Temporary works include any structures erected to support demolition safety: shoring, bracing, debris containment, platforms. All must be properly designed and inspected.

What are 'exclusion zones' in demolition work?

• AOnly during working hours
• BOnly if using heavy equipment
• CClearly marked areas restricting access to prevent people being struck by falling material or exposed to hazards✓
• DDiscretionary

Answer: Exclusion zones are clearly marked and barricaded areas around demolition work. No unauthorized persons are permitted. Zones must extend beyond potential fall distances.

What must be done regarding 'hazardous substances' in demolition?

• AA matter for the client, whose refurbishment survey covers all of the hazardous materials in the building
• BOrdinary care unless material is visible
• COnly asbestos matters
• DSurvey for asbestos, lead, PCBs; remove safely; manage waste; provide respiratory protection if needed✓

Answer: Demolition must address hazardous substances: survey for asbestos, lead, PCBs, and other hazards; remove via licensed contractors; manage waste; and provide worker protection.

What is 'asbestos management' in demolition?

• ARemoving any asbestos that is obvious on inspection and leaving concealed material for the licensed contractor to find at a later date
• BAsbestos can be thrown away
• CSurvey before demolition, notify authorities if asbestos found, engage licensed asbestos contractors, manage waste as hazardous✓
• DDispensed with where the asbestos is bonded into cement sheets, which may be broken up and skipped with general construction waste

Answer: Asbestos in demolition requires: pre-demolition survey, notification to authorities, licensed contractor removal, hazardous waste management, and worker protection.

What is 'dust containment' in demolition?

• AUnnecessary for demolition in the open air, where dust disperses naturally before anyone can inhale it
• BEnclosures, wetting, extraction systems, and respiratory protection to control dust from demolition✓
• CSpraying the debris with water at the end of each working day once the machines have been shut down for the night
• DOnly relevant indoors

Answer: Dust containment includes: enclosing work areas, water spraying, extraction systems, respiratory protection, and monitoring to protect workers and nearby residents.

What is 'utility disconnection' and why is it critical in demolition?

• AAn afterthought
• BSafely isolating and capping all services (electricity, gas, water, communications) before demolition to prevent explosion or injury✓
• CCan be done during demolition
• DOnly electricity matters

Answer: All utilities must be safely disconnected before demolition: electricity (to avoid electrocution), gas (explosion risk), water (flooding), and telecommunications. Disconnection should be by authorized personnel.

What is 'waste management' in demolition?

• ADump waste anywhere
• BOnly large pieces matter
• COnly material that can be recycled needs a waste transfer note; everything else may go in the site's general mixed skip
• DSegregate waste, use licensed waste contractors, dispose to appropriate facilities, manage hazardous waste separately✓

Answer: Demolition waste management includes: segregation of materials, use of licensed waste management facilities, compliance with Site Waste Management Plans, and separate handling of hazardous waste.

What is 'vibration monitoring' in demolition?

• AMonitoring vibration from demolition to prevent damage to adjacent structures and ensure worker safety✓
• BWasted effort on demolition sites, because vibration from machines is absorbed by the material being broken out
• CMonitoring needed only for buildings over four storeys, since smaller demolitions cannot transmit vibration
• DSomething arranged only after a neighbouring owner has complained about cracking appearing in their own property

Answer: Vibration monitoring measures vibration levels from demolition activities to ensure adjacent structures are not damaged and vibration levels do not harm worker health.

What role does a 'Temporary Works Designer' play in demolition?

• ADispensable where the demolition contractor is experienced, as the site foreman can design propping on site
• BDesigns temporary support structures (shoring, bracing) needed during demolition to maintain stability✓
• CRedundant on a demolition project, since temporary works apply only while a new structure is being built on the site
• DOnly for new builds

Answer: Temporary Works Designers engineer temporary structures needed during demolition to ensure structural stability. Their designs must be approved before implementation.

What is a 'Site Waste Management Plan' (SWMP) for demolition?

• ADocument planning waste segregation, reuse, recycling, and disposal for compliance and sustainability✓
• BA voluntary record
• COnly for large projects
• DOnly for recyclable material

Answer: A SWMP details the management of all waste from demolition: materials to be segregated, reuse/recycling opportunities, licensed contractors, and disposal routes.

What is 'selective demolition' versus 'complete demolition'?

• ABoth are the same
• BOnly complete demolition needs planning; selective removal of elements can be agreed verbally with the site manager on the day
• CSelective is less risky always
• DSelective removes some elements while retaining structure; complete removes entire building. Different hazards and controls✓

Answer: Selective demolition retains part of the structure; complete demolition removes everything. Selective demolition may require more complex sequencing and temporary support.

What must be considered regarding 'adjacent structures' during demolition?

• AOnly where the neighbouring building physically touches the structure being demolished, such as a party wall
• BAdjacent buildings matter only where the adjoining owner serves a notice; otherwise they are not the contractor's concern
• CImpact on adjacent buildings, vibration monitoring, dust control, temporary support to prevent damage✓
• DOnly relevant where the adjoining building is owned by the same client as the structure being demolished

Answer: Adjacent structures must be protected from demolition impacts: vibration monitoring, dust control, temporary support or propping if needed, and regular inspection for damage.

What is 'soft demolition' or 'deconstruction'?

• ADemolition carried out with hand tools rather than machines, which is taken to remove the need for a written method statement
• BCareful dismantling to reuse and recycle materials; more hazardous and requires detailed planning than standard demolition✓
• CSomething other than demolition
• DAlways safer than conventional demolition, because materials are removed one at a time by hand from the top of the structure down

Answer: Soft demolition or deconstruction involves careful dismantling to preserve and recycle materials. It often presents additional hazards and requires meticulous planning and sequencing.

What is a 'structural engineer's report' in demolition planning?

• AA discretionary report
• BOnly for historic buildings
• CProfessional assessment of structural condition, sequencing requirements, and temporary support design for safe demolition✓
• DOnly for large buildings

Answer: A structural engineer's report assesses the building's structural system, identifies key load-bearing elements, recommends demolition sequencing, and designs temporary support if needed.

What is 'noise management' in demolition?

• AIssuing hearing protection to the demolition gang, which removes any need to control the noise at source
• BOnly if residents complain
• CControlling noise through equipment selection, silencers, screening, work hours, and hearing protection✓
• DMeasured only when the local authority serves a notice under the Control of Pollution Act on the contractor

Answer: Noise management includes: selecting quiet equipment where possible, using silencers, noise screening, restricted work hours, monitoring levels, and hearing protection for workers.

What documentation must be retained for a demolition project?

• AOnly the invoices and payment certificates, which the client's quantity surveyor keeps for the duration of the contract
• BSurveys, method statements, inspections, incident records, waste documentation, and compliance evidence✓
• COnly final photos
• DMinimal paperwork; once the site is cleared the records may be destroyed as the structure no longer exists

Answer: Demolition documentation includes: pre-demolition surveys, method statements, competency records, inspection certificates, incident reports, waste management records, and disposal certifications.