Property exposures depend upon the work done by the contractor at his own premises. Some contractors have facilities to construct their own piping, so cutting and welding would be done at the yard site. In those cases, fire exposures may be high. Welding has exposure from the storage of tanks of gases that must be handled properly to avoid loss.
The welding operations themselves need good controls. Are the welding operations separated from the other operations either in a cut off area or by flash and welding curtains?
Other fire concerns are from the storage and cutting of the piping and fixtures that may be plastic and pose exposure to toxic fumes should a fire occur. Plastic plumbing and piping use adhesives that may be flammable. Handling and storage of flammables need good controls. If repair work on vehicles and equipment is done in the building, fire hazards may be much higher.
Theft can be a high exposure if inventories of valuable metals such as copper or brass are at both the yard and the job sites.