The five stages → Trades
Trades and sequencing
A stage slips because a trade arrived before the trade in front of it had finished. The dependencies below are the ones that actually bite.
Who follows whom on site
| Trade | Waits for | Blocks | Why |
|---|---|---|---|
| Electrician, first fix | strip-out swept, socket plan marked up | the plasterer | a socket moved after the skim is a patch, and a patch shows through two coats |
| Plumber, first fix | the same strip-out; shares the floor with the electrician | the plasterer | pipes and cables wanting the same joist notch is a return visit for one of them |
| Plasterer | both first fixes tested and signed | the joiner and the decorator | boarding over an untested circuit means taking the board back off |
| Joiner, second fix | plaster dry at the door linings | the decorator | architrave fitted to damp plaster moves as the plaster shrinks |
| Electrician, second fix | plaster dry at the accessory positions | the decorator | cutting a box into green plaster breaks the skim out around it |
| Decorator | all second fix complete | the floor layer | one trade back in after the second coat is one patch per visit |
| Floor layer | decoration finished and dry | the snagging walk | the floor is the surface every other trade is carried across |
The three dependencies that cause most of the slip
Plaster and the drying it is owed
The plasterer leaving is not the plaster being dry. Second fix at the accessory positions and at the door linings waits on the plaster at those specific points rather than on the room as a whole, so second fix is sequenced room by room off the plasterer’s finishing order instead of off one date for the unit.
The joist notch
The electrician’s cables and the plumber’s runs want the same notches in the same joists. Both first fixes are walked together before either starts, with the plan marked up in front of both, and the plumber goes first wherever the two want the same piece of timber, because a pipe cannot be rerouted the way a cable can.
The floor, and everybody who stands on it
The floor goes down after decoration because it is the surface every other trade walks over. The bathroom is the exception: that floor goes down before the suite, because the suite sits on it. The exception is written on the schedule so that nobody later treats it as a mistake and corrects it.
How a clash over a room is called
When two trades want the same room on the same day, the stage the schedule is in decides, not whoever telephoned first. The trade whose stage is current holds the room. The other is moved to the next working day on which the room is free, and the move is written on the schedule the same day so that the stages behind it move with it rather than being quietly compressed.
A stage is never compressed to recover a slip. The durations on the schedule are the durations the work takes. Taking a day out of plaster to recover a day lost at first fix produces a snagging list long enough to cost two, and the snagging stage is the one stage that cannot be hidden, because it closes only when the list is empty.
Durations and what each stage contains are on the schedule of works. What happens once snagging closes is on letting the finished unit.