Cutting material waste on site
On Friday afternoon behind a three-storey wood-frame community health centre, the superintendent looks into the framing bin before its second haul of the week. Most of it is sheathing: offcuts up to a metre long and four full sheets with crushed corners. The estimate allowed 8 per cent waste, and nobody knows the real figure.
Look in the bins before you trust the waste allowance: they show where the main materials go after delivery — offcuts, pieces damaged in handling and storage, good material thrown out at cleanup — and which habit to change first. Wasted material is paid for twice, to buy it and to haul it away. The US Environmental Protection Agency gives source reduction, preventing waste before it is generated, the highest priority, ahead of reuse and recycling. Ordering the right quantity is a separate check: checking quantities before you order.
Find it, then change the habit
- Look in the bin every week with the foreman, before it is hauled: which materials, how long the offcuts, how many full or damaged pieces.
- Count used against the take-off, area by area, for the two or three materials with the most money in the bin.
- Change the cutting: mark a cut plan before cutting, cut at one station, keep an offcut rack sorted by size, and use offcuts before opening a new bundle.
- Change the handling: set bundles whole where they will be used, keep bands and wrap on until the crew needs them, and carry sheets rather than drag or drop them.
- Change storage and issue: a day or two of material per area, stored as the manufacturer instructs and protected from weather and traffic. Usable leftovers go back to stock, not into the bin.
- Show the crew the numbers: what went in the bin last week, what it cost, and next week's count.
Common mistakes
- Treating the estimate's waste allowance as a budget to spend.
- Cutting small pieces from new sheets while offcuts pile up.
- Letting good sheets become dunnage, ramps or temporary covers.
- Binning good pieces at cleanup because nobody knows where they go.
Checklist
The weekly waste check
- The bin looked into before it goes out
- Material used against the take-off
- A cut plan first, and offcuts used first
- Bundles set and opened at the work
- Usable leftovers back to stock
- Last week's result shown to the crew
Check your understanding
A foreman says waste is fine because the job is still inside the estimate's 10 per cent allowance. What do you check before agreeing?
