Ordering pre-cut plasterboards to enhance productivity and reduce site waste
Drywall Contracts Limited (DCL) are drylining specialists that undertook an innovation challenge as part of the innovation driven procurement (IDP) programme. As part of the programme, its site operatives identified the size and weight of plasterboards as a possible opportunity for product innovation along with the possibility of pre-marking the plasterboard with a common coordinating dimension (600mm) for cutting.
The weight of the plasterboards (about 40kg) and size could be reduced to improve handling and installation as manual handling aids are not possible to use in every project context. Weight reduction could also help tackle the problem of an ageing workforce in the drylining trade by making product handling as efficient as possible and preventing experienced workers from leaving the industry due to injury.
The weight and size of plasterboards has been previously investigated with some evidence to demonstrate that the use of lighter and smaller plasterboards can have positive effects on the workforce. The IDP project team at NTU worked collaboratively with DCL and Morgan Sindall on the following:
Investigate the use of smaller sized boards (900 wide mm) across the variety boards commonly in use.
Determine the feasibility of smaller boards in relation to compliance and test data.
Determine if plasterboard weights can be brought in line with other construction products such as bags of plaster or cement (25 kg).
Determine the feasibility of having boards pre-marked with a 600 mm line to posture and improve productivity.
Based on the investigation, a proposal was developed by NTU for engaging with the plasterboard manufacturer to make a case for resizing and reducing the weight of the plasterboards to improve handling and efficiency of installation. DCL and Morgan Sindall engaged the manufacturer to discuss the case for resizing.
Whilst the manufacturer was not able to make any changes to weight because this required changing the material density, they were able to offer an alternative for the material sizes. They could not make the width (size) of the boards narrower to improve manual handling as originally intended. However, they agreed to collaborate with DCL by modifying the length (size) so that these can be ordered to specified pre-cut lengths.
Normally the boards come in standardized sizes of 2.4m, 2.7m and 3m length but building heights have changed and can be 2.5, 3.6 or other height variations. So, for a 2.5m soffit height for example, a standard 2.7m board will be ordered and the operatives will have to cut 300mm of waste for every board or a 2.4m board is ordered and a 100mm strip with additional flat plate is added, giving rise to plasterboard waste and additional labour time. This waste and additional labour time is all avoided if pre-cut lengths that are based on the design specifications are ordered for delivery to site.
The only challenge was to ensure that enough time was allowed to organize pre-cut with the manufacturer.
Traditionally, standard plasterboard sizes can be ordered from the manufacturer for delivery to site in 4 days. Pre-cut orders needed to be placed 6 weeks in advance, which require that DCL will need to be in contracts a lot sooner to allow enough time, with buy in from the main contractor’s procurement team. DCL took up this offer and is now using pre-cut plasterboards across 3 of DCL’s projects. This has made the plasterboards more sustainable in terms of cost and waste, whilst also improving installation efficiency.
Engaging the manufacturer with the initial proposal has now led to DCL being more productive because of a variant of the original issue of weight reduction. For every 10 plasterboards on a typical project, 1 plasterboard is usually accounted for as waste (10%). With each plasterboard weighing up to 40kg, this means that for every 400 kg of board, about 40 kg is wasted. However, on one of the new projects where the pre-cut plasterboards are being used, the waste has reduced by 3-4% and workforce productivity has improved by about 5% (5% saving in labour time).
“If they had a 2.5 metre soffit, you wouldn't send a 2.7m board because it would be too wasteful. Instead, so you would use a 2.4 metre board and then screw that up. Next, they would have to install an additional piece of metal and afterwards cut another part of the board. They wouldn't have to do steps two and three, so it makes it more efficient and less wasteful; I'm definitely happy with that” – Director, Drywall Contracts Limited
With one of the 3 trial projects having over 90,000m2 of plasterboard, 9000m2 of waste would have been generated the old way, but this waste will be reduced to 54,000m2, saving about 36,000m2 of waste. Over a 5-year period, DCL forecast that the savings in waste alone could be more than £50,000 if they ordered pre-cut boards on every job. They have also made savings on skips due to the less waste generated whilst contributing to reduction in carbon emissions. This is also an easy win for main contractors to reduce their carbon footprint, given the push for net zero whilst also resulting in the additional 5% labour productivity improvement.