Use your combustible gas indicator (CGI) to monitor the air around the building.
If gas concentrations do not exceed 1% (or 20% of LEL) and you can enter the building without risk, check for natural gas in the following locations:
- The areas where any underground water, sewer, electric or drain lines enter the building
- The regulator, meter bar and all piping that supplies natural gas as well as the piping around all gas-fired appliances, such as water heaters and clothes dryers
- The spot where the gas service enters the building
- Any cracks in the wall
- All high points in the ceiling where natural gas could collect