6.9 Waste Management During Construction

 

 

6.9 Waste Management During Construction

As outlined in chapter 3, dealing with waste follows a hierarchy starting with the most important measures to reduce, followed by reuse to finally recycle.


Figure 6.9.1 The waste hierarchy for construction materials [see reference 7]

Figure 6.9.1 is sourced from ORBEE under a Creative Commons Licences Attribution-Non Commecial-Share Alike License
http://www.orbee.org/teaching-learning-resources.html?view=oerareas&expand=3%3A25

 

Reduce

The best way of dealing with waste is reducing the amount you create in the first place. This action is often neglected in terms of waste management, but it is by far the most important. The following are methods of waste reduction:

Design specificationThis will be most effective in the planning stages of the project. A lot of waste is created by cutting materials on site to fit a complicated design. This waste can be reduced by considering waste when designing the project designing dimensions to fit available material lengths, simplifying the design and giving thought to the construction type and method.

Material Procurement and Logistics – Construction waste arises from inaccurate material orders, changes to the design midway through the project, or poor storage of materials from badly planned logistics. Generally, material costs have a lower priority than labour costs so arent given as much consideration; this shouldnt be the case as material wastage has a high environmental as well as economic impact. Effective logistical planning can reduce these problems.

Off-Site Manufacturing - Ordering parts of the project to be built off site before delivery can significantly reduce on-site waste. Examples of this include: pre-cast concrete, light steel frame construction and timber framing. The use of timber frame construction has the potential to reduce on site wastage by 40% compared to traditional construction (source: WRAP).

Reduce PackagingThe construction industry has the highest waste arising from packaging in all industry sectors. The site manager can reduce this impact by choosing materials that have less packaging, buying in bulk and recycling packaging wherever possible.


Reuse

There are many situations when materials can be re-used in their raw form. Re-using materials doesnt require energy, so is preferable to recycling. The key is to store materials in good condition on site. Keep on good terms with the builders merchants so you can return goods for cash.

Raw materials that can be reclaimed include timber, tiles and bricks. Sometimes packaging such as crates can be re-used or returned to the supplier. If you dont need the surplus materials maybe somebody else does. The project manager must consider:

What materials can be re-used within their project

What wasted materials from their project could be re-used elsewhere.

Therefore they must have knowledge of where to obtain second hand materials (e.g. reclaimed timber yards), as well as where to take their unwanted reusable materials.



Examples of reusing materials:

  • Topsoil can be reclaimed and re-used for landscaping or as compost once all the necessary tests (for physical properties, chemical composition and moisture content) have been carried out.
  • Bricks (e.g. from an old Victorian house) that are still structurally sound can be reused in certain types of construction and can sometimes fetch a high resale price. Reclaimed timber can often be used for an assortment of jobs.


Recycle

Many materials can be either recycled on site or sent away to be recycled. . An example of on-site recycling is breaking up old concrete or rubble to use as aggregate or hardcore. The key to making waste ready to be recycled is segregation: the on-site sorting of materials before collection for recycling. The following are examples of labels that can be used for bins on site to sort waste:

There are online databases which list all the recycling facilities near the construction site. It will be the job of the site manager to contact these recycling companies and secure pick up and transportation of the separated waste from site to be recycled.

Below are some links to examples of such databases:

Wood: www.recyclewood.org.uk

Glass: www.recycleglass.org.uk

Plasterboard: http://www.wrap.org.uk/construction/plasterboard/plasterboard_4.html

Aggregates: http://www.aggregain.org.uk/supplier_directory/index.html