The Waste You Cut Off Is Money You Already Bought

The problem in one breath

Every roof you build, somebody drives back to the supplier mid-morning for four more bundles — or a half pallet rides back to the yard and sits there till it's the wrong color. Both of those are money you already paid for, and neither one shows up anywhere in your bid.

Why it happens

Waste gets treated like a habit instead of a number. One owner adds ten percent to everything he ever orders because that's what he's always done. The next one orders dead to the squares and lets the crew figure it out. Neither man is measuring anything — a simple gable and a cut-up hip roof with four valleys and three dormers get the same treatment, and the cut-up roof eats the difference out of the job. The shingles you cut off and throw in the dumpster cost exactly the same as the ones you nail down. Nobody ever put that on the bid, so nobody ever priced it.

The play

1. Order off squares-with-waste, never off bare squares. Your takeoff gives you the roof's real area (M10-01). The order goes off that number plus waste. Two different numbers, two different jobs — mixing them up is how a truck shows up short.
2. Let the shape of the roof set the waste, not habit. A long simple gable with two planes wastes very little; there's almost nothing to cut around. A roof with hips, valleys, dormers, skylights and six changes of direction wastes a lot, because every one of those is a cut, and every cut leaves a piece too small to use. Start around ten percent on a two-plane gable and somewhere in the mid-teens once you're counting valleys and dormers — and let the valley feet already on your takeoff decide which of the two this roof is. Those are starting points to correct, not rules; the roofs you actually build will tell you your real numbers inside a season.
3. Count the cut-up work instead of feeling it. You already logged linear feet of hip and valley on the takeoff. That's your evidence. A roof with eighty feet of valley is not the same roof as one with none, and now you can say so with a number instead of a hunch.
4. Don't forget the material that isn't field shingle. Starter and ridge cap get cut from bundles or bought as their own product. Either way they come off linear feet, not off squares — if they're riding inside your waste percentage, your waste percentage is doing two jobs and lying about both.
5. Check yourself on the back end. At the job debrief (M3-01), the foreman writes down two numbers: bundles left over, and anything he ran short of. Ten jobs of that and you stop guessing forever — you'll know your waste by roof type, off your own roofs. What those leftovers cost you in dollars is priced in Module 15, Play 2.

Do this this week

On the next three tear-offs, have the foreman write leftover bundles and any short runs on the debrief sheet before he leaves the job. Nothing else. That's the beginning of the only waste number that will ever be true for your shop: your own.

The tool

No spreadsheet. The takeoff sheet in M10-01 already carries a waste cell, and this is the play that tells you what to type in it. Print this and tape it inside the estimator's binder:

  WHAT MAKES THIS ROOF WASTE MORE — check them before you set the number

  ADDS LITTLE            ADDS A LOT
  [ ] long simple planes  [ ] valleys (count the feet)
  [ ] one ridge, no hips  [ ] hips on every corner
  [ ] square footprint    [ ] dormers, turrets, cut-ups
                          [ ] skylights & chimneys to cut around
                          [ ] steep pitch (more breakage, more scrap)
                          [ ] pattern or color you can't blend from stock

  Starter and ridge cap come off LINEAR FEET, not off your waste %.
  Order = squares from the takeoff  +  waste %.   Never bare squares.
  Back end: leftover bundles ____   ran short ____   -> onto the job debrief.

If your crew is 1099

Asking a sub crew to leave you a leftover-and-shortfall count is a delivery term, not you running their men — write it into the sub agreement with everything else you expect handed back at the end of a job. What you don't do is stand on the roof telling a sub crew how to cut their valleys.