Building and Housing Codes Department
Frequently Asked Questions
Tom Winbush, Director
119 E. Main, Suite #208
Jackson, TN 38301
What is a Backflow Preventer?
A backflow preventer is a device which prevents the reverse flow of water due to atmospheric or higher pressure by means of positive check members in addition to atmospheric ports which provice back siphonage protection.
Why is a Backflow Preventer used?
Backflow preventers are required between the City water mains and the customer's piping to protect the public water supply from possible contamination from back siphonage (water running from the customer's piping into the public water supply). Under normal conditions, this would not occur. However, there are conditions which cause low pressures on the city main and/or high "back" pressure on the customer's piping. For example: If a fire were occurring and pumpers were connected to fire plugs, a possible negative water pressure (suction) could result. If a customer had a hose connected to a bibi and the opposite end of the hose in a bucket of liquid fertilizer, he/she happened to be mixing at the time, the liquid fertilizer could utterly be sucked into the city main. This would result in the city water supply becoming undrinkable.
Where & When should a Backflow Preventer be utilized?
Backflow prevention devices are required on all new plumbing installations and adaptations of existing, and/or changes of occupancy, except for one and two family dwellings. In apartment complexes with individual water meters, backflow prevention devices are required only on the lines serving common facilities (laundries, swimming pools, lawn sprinklers, etc.). Backflow prevention devices are required on any individual line serving a boiler, cooling tower or other piece of equipment where back pressure exists or extremely hazardous solutions are used.
At what point is a licensed contractor required?
The State contractors law goes into detail regarding the type of work and dollar limits a contractor is limited to by the type of license he/she possess. Typically speaking, a licensed general contractor is required anytime the dollar value of a project exceeds $25,000. Not that the $25,000 figure must include all phases of the work (building, plumbing, electrical, gas, mechanical, etc.) as the owner may not contract for work up to $50,000. If a sub contractor is working for an owner or someone who is not a licensed general contractor, his limit is $25,000.
How many layers of roof covering can I install on my roof?
The 2006 International Residential Code section R907 states:
R907.3 Re-covering versus replacement. New roof coverings shall not be installed without first removing the existing roof coverings where any of the following conditions occur:
- Where the existing roof or roof covering is water-soaked or has deteriorated to the point that the existing roof or roof covering is not adequate as a base for additional roofing.
- Where the existing roof covering is wood shake, slate, clay, cement or asbestos-cement tile.
- Where the existing roof has two or more applications of any type of roof covering.
- For asphalt shingles, when the building is located in an area subject to moderate or severe hail exposure according to Figure R903.5.
When the existing roof covering is removed, any damaged decking or joists must be repaired or replaced prior to the installation of the new roof covering.
How do I get an electrical meter set on new residential or commercial building?
There are a couple of ways a residential or commercial building can get an electrical meter set. First, the electrical contractor must contact Jackson Energy Authority (JEA) to get a “meter spot”, this is the location on the building where JEA will attach the overhead or underground electrical service.
Next, an electrical permit must be purchased for the “amp” size of the service. For example, 100 amp, 200 amp, etc, fees are based on “amp” size. An “amp” permit allows the contractor to get a rough-in and final inspection only. Once a final electrical inspection has been requested by the contractor and approved by the electrical inspector, JEA will be contacted and an electrical meter will be set.
However, at some point during construction, the electrical contractor may need the electrical service turned on. The contractor can then purchase a Temporary Service Entrance permit for a fee of $30. The electrical service must be completed with at least one G.F.I. protected receptacle installed. All covers for the service equipment and any potentially energized outlets must be in place. This is a temporary service inspection only; the final electrical inspection should still be requested when the job is complete.
Temporary services must be in compliance with Article 305 of the 1999 National Electrical Code.
For any questions contact: Devilon Young: Commercial Electrical Inspector @ 425-8256 or Jeff Clark: Residential Electrical Inspector @ 425-8226.