KNAUF DRYWALL ANTI-WASTE INITIATIVES GENERATE BIG SAVINGS
Innovative design detailing and improved plasterboard waste management combine to generate significant building site savings and environmental benefits. On-site evidence from successful tests at a major residential development in East London underline the potential for savings on material and waste costs through cutting the weight and volume of plasterboard waste. Knauf Drywall Marketing Manager Bob Stark says the findings are excellent news for builders – and the environment.
The plasterboard waste stream was measured over several similar floors of the spectacular Elektron development overlooking the River Thames at Leamouth, where Barratt East London is building 437 high-specification apartments in three concrete frame buildings, up to 25 storeys high. Dry lining subcontractor BDL Group is working with Knauf Drywall systems to shape the individual apartments. Plasterboard waste is collected in 660-litre wheelie bins on each floor, and sent to the Knauf Plasterboard Waste Recycling Service.
The tests, using the average waste production on two typical floors as the baseline, measured the benefits of Knauf Drywall’s design for a low-waste door jamb, coupled with chipping the plasterboard offcuts to avoid wasting space in the bins. The results showed that:
• Installing the Knauf Eco Door Jamb instead of the standard British jamb reduced plasterboard waste by 27%, and cut the number of bins required from 44 to 32 per floor.
• Use of a Knauf Plasterboard Chipper increased the average weight of waste plasterboard in each bin from 118kg to 175kg and reduced the number of bins by 32% from 44 to 30 per floor.
• Combining the Knauf Eco Door Jamb and the Knauf Plasterboard Chipper reduced the number of bins by 50%.
The combined figures showed a reduction of 1.42 tonnes of waste per floor – reducing overall plasterboard waste from 16% to12% – with 22 fewer bin movements to and from the collection vehicles. A typical floor at Elektron consisting of five apartment types and common areas uses 32.3 tons of plasterboard, and includes 52 doorways in drywall.
“Budgeted plasterboard waste on building sites ranges from 10 to 25% – much of which adds unnecessarily to the financial and environmental costs of construction,” says Bob Stark. “The study is clear evidence of the savings potential in design innovations and smarter ways of dealing with the waste stream. Over the whole building industry, savings of this nature are potentially huge.”
He says the Eco Door Jamb is part of Knauf Drywall’s programme to reduce plasterboard waste through sound technical solutions. It enables the installer to create a doorway from standard plasterboard sheets more economically than with the standard British design – without affecting the final appearance or structural integrity of the jamb. The new design uses full size boards, on studs at normal centres, up to the edge of the doorway. Additional strengthening studs are placed no more than 150mm from the door edges. A spandrel panel, cut to fit above the doorway, is fixed to cripple studs.
The Knauf Drywall chipper uses an easily relocatable machine supplied by Starke Arvid, to reduce the labour involved in breaking up plasterboard offcuts at the workplace and to fill the dedicated collection bins more efficiently. Chips can be fed directly into a bin, or via a waste chute to a bin on the ground.
“The chipper breaks the offcuts into 140mm x 100mm pieces, which is conveniently small without creating dust. Plasterboard waste handled in this way is readily recyclable, as both the gypsum core and the fibres of the paper liner can be re-used. Recycling avoids the costs and ecological problems associated with sending gypsum waste to landfill,” says Bob Stark.
Vinny Walker, BDL Group Regional Director, says the control of waste is an increasingly major issue on building sites. “We are always looking for new ways to reduce waste,” he says. “Designing waste out of the building process produces the best financial and environmental solutions. The Knauf Eco Door Jamb undoubtedly helps reduce waste, while using the plasterboard chipper facilitates removal of waste and significantly reduces the vehicle movements required for collections.”
Barratt East London supported the project by agreeing to test the door jamb and by providing space on site for the storage and segregation of the wheelie bins.
Paul Robinson, Barratt East London Project Manager, says: “The results prove impressive cost savings can be achieved by careful construction detailing at the design stage, and management of board offcuts on site. Benefits can be maximised on site by careful consideration of how the waste is segregated, transported and stored at all stages.”