Demolition and clearances of commercial and industrial sites
Site clearances carried out as part of commercial or industrial demolition projects must take into account many considerations - depending on the type of site and waste materials present. Some common examples of commercial sites requiring complete demolition & clearance are:
- Factories and industrial manufacturing facilities
- Office buildings/blocks
- Commercial retail units
- Warehouses and storage facilities
Demolition site clearances
The majority of commercial site clearance processes typically follow the demolition of main commercial/industrial buildings and structures. The site clearance process refers to the process of sorting, removing, recycling &/or transportation of rubble, debris, utilities, machinery & hazardous waste materials from a location so that it can either be re-used or disposed of safely.
Whatever the site , the waste must be dealt with with due care and consideration. Some waste has high value (.e.g. scrap metal and other assets) and will help cover the demolition cost - whereas some may be hazardous and has to be dealt with in a controlled way. The majority will be recyclable and local authorities will demand that a commercial site clearance be carried out correctly as part of granting planning consents.
Situations requiring site clearances
A commercial or industrial site clearance can become necessary because of a number of situations:
- The owners of the commercial site want to change the usage of some or all of the site
- The commercial site has previously been abandoned & been subject to fly-tipping or vandalism and must be cleared
- An incident (e.g. fire, flood or chemical spill) has caused significant damage to an area making it unsafe or contaminated
Site clearance contractor services
A fully project managed commercial or industrial site clearance usually requires a demolition contractor who can provide a portfolio of services to occur in conjunction with structure demolition - these include:
- Disconnection of live services
- Soft stripping
- Floor by floor deconstruction
- Waste handling & sorting
- Screening, crushing & recycling of concrete
- Asbestos removal
- Other hazardous waste disposal
- Dismantling of plant & equipment
- Scrap metal/asset recovery
- Groundworks & excavation
- Underground tank removal
Some demolition and commercial site clearance contractors will be able to provide all of the above services as in-house services (as part of a group of specialist companies) - some may use trusted sub-contractors.
Management of site clearance waste
When demolition & site clearance contractors deal with the waste from a project there will be many considerations depending on the construction and demolition (C&D) waste to be disposed of.
Presently, approx 30% of UK waste comes from the construction & demolition sectors - (Approx 100M tonnes of waste/year, half of this amount is recycled and approximately 25M tonnes goes to landfill (Defra, AEA Technology, bre, 2007.)
Construction and demolition (C&D) waste material from a commercial site clearance typically includes:
- Metal alloys
- Roofing materials
- Electrical wiring
- Tree stumps & plants
There are a number of financial schemes which provide incentives to demolition and site clearance contractors to maximise the recycling rates they achieve of the above materials - some examples are:
The UK Landfill Tax was introduced in 1996 to decrease the level of waste going to landfill. It was initially set at:
- £24 per tonne for active waste
- £2 per tonne for inert materials (rocks, soils, ceramics and concrete)
At the time of writing (late 2016) the rates are:
- £84.40 per tonne for active waste
- £2.65 per tonne for inert materials
The Aggregates Levy
The Aggregates Levy was launched in 2002, is an environmental tax on the commercial exploitation of aggregate (sand, gravel and rock) to reflect the costs associated with quarrying those materials - it is presently charged at at £2 per tonne of sand, gravel or rock. This makes sure that crushed concrete aggregate from commercial & industrial site clearances
Dealing with construction waste materials
With the mixture of demolition waste arising from an industrial or commercial site clearance - different constituent elements will be dealt with in different ways by site clearance contractors - some guidance is below:
Recycling of metal from a site clearance
After a site clearance there may be large quantities of metal that can be recovered for a scrap value. Recovered metals from a commercial site clearance are split between non-ferrous and ferrous metals.
Ferrous Metals mostly contain Iron, are magnetic and give little resistance to corrosion. Non-Ferrous Metals do not contain Iron, are not magnetic and are usually more resistant to corrosion - some examples are:
- Aluminium & Aluminium Alloys
- Stainless Steel
- Electrical Cable
Apart from the steel building structure the recovered metal components can be part of equipment that has reached the end of life - in some cases specialist equipment can be salvageable for re-use through asset recovery at a higher value than scrap.
Removal of asbestos from a site clearance
Typically the most hazardous demolition material from a commercial or industrial site clearance is asbestos - (asbestos related diseases still accounts for approx 4000 UK deaths per annum.)
Asbestos is likely to be present in a commercial site clearance - having been used extensively as a building material in the UK ( 1950s to the 1980s) - over half a million industrial & commercial buildings could currently contain asbestos.
The main forms of asbestos to be dealt with in commercial & industrial site clearance & demolition projects are:
- Sprayed asbestos and asbestos loose packing – generally used as fire
- breaks in ceiling voids.
- Thermal insulation of pipes and boilers.
- Sprayed asbestos used as fire protection in ducts.
- Fire breaks, panels, partitions, soffit boards, ceiling panels and around
- structural steelwork.
- Asbestos insulating board (AIB) used for fire protection, thermal insulation,
- partitioning and ducts.
- Asbestos cement products, including gutters, rainwater pipes and water
- tanks and corrugated sheets, largely used as roofing and wall cladding.
- Certain textured coatings
- Ceiling tiles & Bitumen roofing material
- Vinyl or thermoplastic floor tiles.
There is a legal requirement to remove most asbestos-containing materials (ACMs) from buildings prior to demolition. This will be done by specialist contractors and taken to an appropriate asbestos disposal facility
Recycling of concrete from site clearances
When concrete structure are demolished, recycling practices must ensure a that the the commercial or industrial site clearance contractor sends a minimum level of concrete waste to landfill.
Industrial & commercial demolition contractors typically arrange a concrete crushing & recycling service (many companies have will have on-site crushers as part of their demolition vehicle fleet). If all of the crushed aggregate is not required on site, this can be sold on for subsequent construction projects
Sorting other demolition waste from site clearance
Demolition waste which cannot be separated and processed on site will be taken to a materials recovery facility (either run privately or by local authority). Using a combination of manual and automated sorting processes, the demolition waste is separated until only the non-recyclable elements remain to go to landfill.
Examples of industrial & commercial site clearances
Below are some examples of considerations for site clearances in the demolition of some types of industrial & commercial buildings
Industrial site clearance issues for: Factories
Factories describe a very broad range of industrial buildings & include many types of production & manufacturing environments such as:
- Petrochemical & energy
- Food & pharmaceutical production
- Paper & pulp
- Chemical processing
A big consideration in any factory site clearance is the decommissioning and dismantling of plant & equipment (deplanting) for maximum value - this will require specialists in asset recovery.
Typical assets to be recovered from a factory site clearance project include:
- Motors, pumps & compressors
- Reactors & mixing vessels
- Power Generators
- Power Plants
- Chillers & condensers
Other issues include:
- Fuel/chemical storage tank degassing, cleaning & removal
- Explosive demolition & clearance of chimneys and cooling towers
- Disassembly & relocation of plant if business moving premises
- Asbestos containing materials including AIB, asbestos sprayed limpet, vessel lagging and asbestos lagged pipe work
Commercial site clearance issues for: Warehouses
A warehouse site clearance may not present such the same risks as a factory to a contractor - however they still can take the form of very large buildings up to several hundred thousand square feet.
Warehouse racking presents a very valuable asset and care should be taken by the warehouse demolition contractor to maximise the amount that can be recovered.
Other recoverable elements from a warehouse include:
Conveyor systems Removal and relocation of heavy duty machinery Temporary ceilings and floors Non load bearing walls Heating systems including ducting pipes and air con systems Redundant gas and water pipes Electrical cables including lighting and cable trays
Commercial site clearance issues for: Offices
If an office in a town centre location with listed status then there may need to be facade retention while soft stripping & the remaining building structure is removed.
Office building clearances may have large amounts of cable & redundant office equipment - the disposal of any electronic equipment has to comply with the WEEE directive.
Commercial site clearance issues for: Large retail units
Commercial retails units typically using large amounts of steel in their construction (steel portal frame structure). When dealing with a commercial retail unit demolition the type of structure needs to be assessed & disassembled carefully - often using manual metal cutting techniques
Services after a site clearance
After an industrial or commercial demolition & site clearance project - the site can be prepared for future usage. The site clearance contractor can provide additional services to prepare the site for future use, include:
- Erection of site signage & boundary fences
- Forming and sculpting land contour (groundworks)
- Landscaping & planting schemes
- Installation/re-routing of underground services and utilities including telecommunication, cable, electric, gas, water, storm and foul drainage
- Creation of manholes and storm drains
- Creation of water channels & soakaways
- Creation of roads, footpaths with installation of area lighting
- Excavation for new building foundations
- Underground drainage to damp proof course
- Installation of foundations to damp proof course
- Laying of a concrete bases floor slab
The stages of a site clearance project
All site clearance projects will go through the same approximate stages - complex projects such as factory demolition will require additional stages such as decommissioning/ deplanting stages (to ensure maximum asset recovery value).
The typical stages are as follows:
- Site Evaluation
- Estimation of the type and quantity of waste types to be cleared from the site
- Identification of potential hazardous wastes
- Evaluation of the contaminated land
- Creation of a WASTE MANAGEMENT PLAN
Task Lists: A number of tasks are commonly involved in site clearance
- Planning of Site Clearance Project
- First item
- Second Item
- Third Item
Removal of large heavy materials, liquids, hazardous soils & industrial waste.
- Demolition Site
- Asbestos containment & removal
- Break-up and removal of concrete foundations, slabs & hard-standings
- Sorting of residual site waste
- A GLAMOUR BULLET POINT REQUIRED
- Commercial Site
- Commercial building soft-stripping
- Removal of abandoned or returned stock
- Removal of refrigeration units
- Land Clearance
- Tree felling and root clearance
- Hedge clearance
- Removal/addition of soil from/to a site
- Levelling of the land
- Organising and removal of fly-tipped waste
- Factory Site
- Identification of hazardous waste
- Hazardous waste removal planning
- Removal of underground tanks
- Removal of production machinery
Note that large industrial factory site project may require on-site chemical analysis.
- Demolition Site
Execution of Site Clearance Project
Environmental Audit of Cleared Site
- Decide if there is a need for industrial cleaning programs to remove residual contamination from a site
What is a site waste management plan?
A waste management plan documents the: * amount and type of waste that will be produced * how the residual material will be re-used, recycled or disposed of
A waste management plan will reduce construction, or demolition waste going to landfill.
What waste management legislation must be considered?
Until 2013 contractors in the UK carrying out building site clearance work on a clients behalf were subject to the following legislation:
Small site clearance projects < £300k
Smaller projects below £300k in value (or within the size range of 20-250 sq meter (residential), or 40 - 200 sq meter (commercial)), require a site waste minimisation statement in order to comply with BH05.08.
Medium site clearance projects from £300k to £500k
Site clearance projects exceeding £300k (but below £500k) in value are subject to regulation requiring a site waste management plan.
Large site clearance projects > £500k
For larger projects exceeding £500k in value, the site waste management plan must fulfil additional requirements.
These project valuation categories were on a per project per site basis i.e. for larger, multi-site projects a site waste management plan was only required on individual sites with project values exceeding £300k. Splitting the projects costs in such a way to avoid a site waste management plan requirements at either the £300k or £500k thresholds was unacceptable.
Following a consultation the aforementioned legislation was subsequently removed because it not only reduced red tape and administration costs. A contractor may, however, decide that it is still in their interest to do prepare a site waste management plan because it promotes the minimising of material, disposal & labour costs.
Site waste management legislation had applied broadly across the demolition & construction industry. Example projects include:
- Residential, commercial & industrial onstruction
- Building Renovation/ Conversions/ Alterations
- Industrial/ Commercial Building Fit-outs
- Site clearance
- Land remediation (e.g. soil cleaning)
- Plant commissioning/decommissioning
- Industrial demolition/dismantling
- On-site assembly