There are a couple of reasons why volunteer fire departments don’t work in many cases. In rural communities, they are an excellent resource, but after a response area reaches a certain size, they generally (with a few exceptions) don’t work.
1. Insurance companies: The real mission of the fire department is not to put out fires. It is to save the members of a community money through reducing insurance costs. Fire departments are rated by the insurance services organization on a scale of 10 (no fire department) to 1 (very few departments achieve this). Rankings range from 1 to 10, with 1 being the best and 10 being the worst. An ISO Class 3 rating is a very good rating especially for a department that has both paid and volunteer staff. Class 1 is very difficult to achieve as it means total fire protection. Departments that are outside city limits tend to receive Class 8 or 9 because of extended response times and lack of water supply, and this is true whether or not the department is paid or volunteer.
This is where volunteers shine. In rural areas, the cost/benefit of maintaining a paid department is out shone by volunteers.
2 Liability: In general, it is difficult to discipline volunteers. After all, it isn’t as if you can suspend them without pay or terminate them. In addition, many younger volunteers tend to drive way, way too fast when responding to calls, and they tend to freelance more. This causes liability issues, especially in urban areas where there are more chances of hitting someone.
3 Activity levels: The training and response levels demanded of firefighters increases every year. In urban and busy suburban departments, a fire station may easily run 3,000 or more calls per year. It is difficult to find volunteers who will dedicate themselves like this. I know there are departments who have volunteers at this level, but they are the exception, and not the rule.
There are other reasons, but these are the big ones. I say this after spending 8 years as a volunteer and having to face all of the above issues. Volunteerism used to be fairly strong in central Florida, but it has all but disappeared within the last 5 years. That is also the case in many other areas of the country.