What is a hot works permit?
A hot works permit is a written authorisation for work producing heat, sparks or flame — welding, grinding, soldering, torch-on roofing — issued for set conditions and signed back after a watch period.
Hot works are among the most common causes of fire in occupied buildings under refurbishment, and the fire usually starts somewhere the operative could not see: in a void, behind a wall, or in material that smouldered for an hour.
That delay is why the permit includes a watch period after the work stops. Signing a permit back the moment the torch goes off skips the part of the control that addresses how these fires actually develop.
The permit also handles the alarm. Detection in the work area normally has to be isolated to avoid unwanted signals, and reinstating it is part of closing the permit rather than an afterthought.
In practice
Welding finished at four on a Friday afternoon.
The permit was issued carefully, the area was cleared and detection was isolated. Everybody left at five.
Hot work starts fires after the work has stopped, which is why the permit is not closed until somebody has gone back and checked the area and restored the detection.
A permit with no cancellation entry is an area nobody re-checked.
What goes wrong in practice
- Closed immediately at the end of the task with no watch period.
- Detection isolated for the works and not reinstated at the end of the day.
- Issued for a whole project rather than for a defined task, place and period.