Emergency response

Water inside an occupied building is an operations problem first

On a commercial building the roof leak is usually the smaller cost. The larger ones are the tenant whose stock got wet, the production line that stopped, and the ceiling grid and floor covering that have to be replaced afterwards.

What to do in the first hour

1. Contain and divert. Bins, poly sheeting run to a drain, and anything valuable moved out of the path. A temporary diversion above a ceiling grid saves far more than it costs.
2. Deal with the electrical risk. Water into fittings, panels or racks means isolating circuits rather than working around them.
3. Photograph everything, with times. The affected area, the ceiling, the contents, and the water itself.
4. Note the weather. Wind direction and rainfall intensity are diagnostic: a leak that only appears with wind from one direction is a different defect from one that appears in every heavy rain.
5. Record where it entered the space, which is rarely where it entered the roof, but is the starting point for tracing it.

What temporary work can and cannot do

Emergency work on a wet, and often windy, roof is about getting the water stopped safely. That may be a membrane patch welded in, a temporary dry-in over a damaged area, or sealing a specific detail that has failed. What it is not is a diagnosis: the same conditions that make the leak urgent make the roof difficult to assess properly.

Tracing it properly, afterwards

1. Start from inside and work up

   Water travels along deck flutes, purlins and conduit before it drops. The entry point can be a long way from the stain, especially on a metal deck.

2. Check the usual suspects in order

   Penetrations and curbs, then drains and scuppers, then terminations and edge metal, then seams, then the field. The field of a membrane roof is rarely the cause.

3. Look for the trade that was up there

   A new conduit run, a fresh satellite mount, an abandoned unit cut free and left. Unflashed penetrations left by other trades are one of the most common causes of a sudden leak on a roof that was fine for years.

4. Scan for wet insulation where it matters

   Where a leak has been running for a while, the wet area under the membrane is usually much larger than the entry point, and it does not dry out.

5. Write it down for the file

   What leaked, what was found, what was done, and what remains. That record is what stops the same leak being rediscovered from scratch next year.

Insurance and the paperwork

Commercial policies differ far more than residential ones, and the interesting questions are usually about the contents and the business interruption rather than the roof itself. What helps in every case is dated documentation of the loss and of the emergency measures taken to limit it. The insurance section covers the general mechanics; your policy and your broker decide what applies to your building, and nothing here predicts a carrier's decision.