The National Electrical Code mandates that plastic-sheathed wires (commonly known as Romex) be safeguarded in high-risk regions. You may not require conduit if you can run the plastic-sheathed wire high in the cabinets or behind drawers. But if water is a concern, then you should consider using conduit.
You can also run Romex in shallow boxes attached to the wall with metal screws. Make sure that you use metal screw heads instead of wood so that over time they will not become an electrical hazard themselves. Attach the boxes to the wall using metal-stud anchors or drywall screws. Then cover the holes in the box with tape or filler material before adding paint or wallpaper.
Do not use staples, glue, or tape to attach cables to walls. They can cause problems later if the cable needs to be moved or replaced.
Cable must be able to withstand a load before it begins to fail. If it cannot, then it is not adequate for most applications. For example, if a person were to touch both ends of a piece of wire that has been used as a ground, it would be called a "third rail". Such wire is not suitable for lighting purposes because it will not stand up to being touched repeatedly by people walking across it.
The trademark name Romex refers to non-metal sheathing wire. To summarize the National Electrical Code (NEC) standards, Romex wire should not be left exposed anyplace in the house, including the basement, attic, or the house itself. The cable should be securely fastened or, preferable, run via a conduit. The usual purpose for using Romex is to provide electrical service within buildings before the metal wiring system is put in place. This allows outlets to be installed wherever they are needed without having to first tap into the metal piping with special tools.
When Romex is used as the sole means of electrical distribution inside a building, it must be done according to code requirements. The cable needs to be properly terminated and arranged so that no two circuits are tied together. Also, make sure that you use only certified Romex wire when using it as supply lines inside buildings. Non-Romex wire cannot be used as supply line material because it will not meet code requirements. Certified Romex is manufactured to specific specifications for use as supply line wire; otherwise, it can cause serious injury if it comes in contact with electricity.
If you own a home built after 1990, then you know how important it is to have your water meter placed in an area where it will not be damaged by water. The same thing goes for your gas meter. If these essential parts of your home energy management system are exposed to weather conditions, they may fail prematurely.
The applications for Romex wires are many, but most DIYers are perplexed about whether they can strip Romex and use it in a conduit outside. Yes, it is a resounding yes. In reality, the National Electrical Code (NEC) requires that all non-metallic wires be used in conduits to minimize physical harm, particularly if stripped. This includes using only solid core wire when possible.
If you have Romex running throughout your home with no outlets present, you should check with an electrician to make sure these lines aren't part of a live circuit. If not, then they can be included in your conduit installation without causing any problems.
You should also call in an electrician if you plan on using any appliances that could cause damage if they became energized, such as washers, dryers, and dishwashers. These types of devices need to be located away from your conduit installation in case they malfunction and contact the line. A qualified electrician will be able to assist you in determining what type of conduit is required for your specific situation and help you select the right materials for your project.
Conduit is needed only if the route you choose goes beyond the interior of one dwelling unit. For example, if you want to run cable through the walls of a large room or entire house, you will need to include a junction box at each end of the conduit section.