YOU STARTED FIVE WEEKS LATE. YOU FINISH ON THE ORIGINAL DAY.
Drywall comes after MEP rough-in and before finishes. Every upstream trade that takes longer than planned pushes your start, and nobody moves your completion, so a nine week window becomes six and the missing three weeks get bought back with premium labour.
On a $240,000 hang and finish package, a five week mobilisation slip against a fixed completion date compresses a nine week window to six. Buying back three weeks of production costs about $10,980 in premium hours and second crew learning curve. Drywall subs at $1M to $5M average 19 percent gross, so that job held $45,600 of gross profit and the compression took 24 percent of it, closing the job at 14.4 percent. The delay was upstream and the cost was yours.
Nothing here is a production failure and your crews did not slow down. A calendar moved on one end only, and the trade in the middle paid for it.
This post covers one schedule mechanic and what it costs. That page covers the three places drywall margin goes and how the trade is managed month to month. Read Drywall Operating System for the complete treatment, worked figures included.
WHY DOES DRYWALL ALWAYS START LATE?
Because you cannot hang board over rough-in that has not passed inspection. Framing has to be complete, mechanical, electrical and plumbing all have to be roughed and signed off, and insulation has to be in. That is four trades and at least two inspections in front of you, and every one of them owns part of your start date.
None of them owns your finish date. Finishes do. Paint, flooring, casework and ceilings are all waiting on your board, and the certificate of occupancy is waiting on them. So the back end of the schedule is defended by everybody and the front end is defended by nobody.
A drywall subcontractor is therefore the trade with the most people ahead of it and the least float behind it. That is a structural position on the schedule, and it does not improve with a better crew.
WHAT A FIVE WEEK SLIP DOES TO NINE WEEKS.
Take a $240,000 hang and finish package bid at nine weeks. Labour is roughly 55 percent of that contract, so $132,000, and the production plan assumes a single crew working straight time.
MEP rough-in takes three weeks longer than planned and the inspector needs another two for a re-inspection. You mobilise five weeks late. The finish trades are already sequenced and the owner has a lease commitment, so completion does not move. Nine weeks of work now has six weeks of calendar.
There are only two ways to buy back three weeks. Work longer days, or add people. Both cost more per unit of production than the bid assumed, and neither is a change order unless somebody wrote one.
WHERE THE $10,980 ENDS UP.
Saturdays and ten hour days first. Say 320 premium hours across the crew at a $19 per hour differential once burden is on it. That is $6,080, and it is the visible half.
The second half is harder to see. Adding a crew to a job already in motion means two weeks of somebody learning a board layout, a stocking route and a GC's punch standard that the first crew already knows. Call it $4,900 of production that got paid for and did not get installed.
Together that is $10,980. The job held $45,600 of gross profit at drywall's 19 percent, so the compression took 24 percent of the job's profit and closed it at 14.4 percent gross. Your bid was fine. Your calendar was not.
MOST SUBS MISS THIS: THE CLOCK STARTED WITHOUT YOU.
Here is the part that costs money on the next twelve jobs. The overtime is booked to your labour cost code, so the job cost report says drywall labour over budget. It does not say drywall labour over budget because the window was cut by a third, because the report reads cost codes and a cost code has no calendar in it.
So the review meeting goes looking for a production problem. Are the crews too slow. Should we be piece rating the hang. Is the foreman managing the stock properly. Every one of those questions is fair and every one of them is aimed at the wrong number.
The number that moved was days available, and nobody tracked it. If you want one thing off this post, put two dates in your job setup: contracted mobilisation date and actual mobilisation date. The difference between them, in days, is the single best predictor of whether that job will overrun labour, and you have it before you hang a sheet.
THE FOUR LINES THAT MAKE IT BILLABLE.
None of this requires renegotiating a contract. It requires four things in writing at the front, and a subcontractor who sends one email on the day the slip happens.
1. A contracted mobilisation date in the subcontract, alongside the completion date. A completion date with no start date is a duration you never agreed to.
2. A clause saying that if mobilisation is delayed and completion is unchanged, the compressed duration is a change in the work and premium time is compensable.
3. A notice email on the day you learn the start moved, stating the new available duration and the premium cost of holding the original completion. Sent before the overtime, not after.
4. A separate cost code for schedule acceleration, so the premium hours go somewhere other than base labour and the review meeting can see them.
WHAT THIS IS WORTH ACROSS A YEAR.
One job at $10,980 is a bad month. Repetition is the problem. A drywall sub with $2.5M spread across eight to twelve packages a year, with half of them compressed to some degree, has $40,000 to $60,000 of unbilled acceleration.
Drywall at $1M to $5M averages 6 percent net against a 10 percent target, the thinnest spread in the finish trades. On $2.5M that distance is $100,000, and unbilled acceleration is a large piece of it.
A bigger crew and a harder foreman both leave this in place. What closes it is a start date in the contract and an email on the day it moves.
THE SHORT LIST.
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