Putting wire in conduit is a simple way to protect it from physical damage and wear and tear. It can also improve the appearance of the wiring, making it more discreet. In some cases, conduit must be used with wire.
Does wire in the attic need to be in conduit?
While this is not a strict requirement, there may be some benefit to putting wires that are located in your attic in conduit. If the wiring is likely to be moved, putting it in conduit will protect it. However, it is not always essential and depends on other factors like the type of wires you’re using.
An electrical conduit is used to route wiring around a building.
Not only does it protect the wire from damage, but it also makes it easier to organize your wiring and make it less noticeable.
Although you don’t necessarily need to use conduit for wires in the attic, there are certain scenarios where this may be advised.
In this guide, I’ll provide you with all of the information you need on this subject.
Does Wire in an Attic Need to be in Conduit?
Using a conduit may be beneficial for the wire in your attic, but it is not essential in most cases. There are some exceptions to this if your local wiring regulations require the use of conduit for wiring in your home.
While the wire in your attic doesn’t necessarily need to be in conduit, there are several benefits to this. Firstly, the conduit will protect the wiring from any pests that are in the attic.
- Attics are generally dark spaces that can easily become damp and infested with rodents or insects. Mice and rats are likely to bite through the wires in the attic if they are not in conduit, which could result in the electricity being disrupted.
Unfortunately, the plastic coating that surrounds the inner wires is not robust enough to prevent such an occurrence from happening.
Rodents can easily chew through the material, exposing the inner components of the electrical cable and making it less resistant to damage.
Another reason that it might be a good idea to use conduit in your attic is that it keeps all of the wires together in one secure place.
This prevents them from being moved around too much or being damaged when accidentally stood on.
Some local areas require electrical wire to be used with conduit, to make it safer and less likely to cause any issues.
It’s a good idea to check the regulations of your area to determine whether you need to use conduit in your attic.
- If the wires are positioned somewhere that rodents cannot reach them, and they are unlikely to be moved or stood on, you may not need to put them in conduit.
This will vary with each case, so if you’re unsure it may be worth getting a second opinion from an experienced electrician.
In the majority of cases, you don’t strictly need to use conduit for your wires in the attic.
Nevertheless, doing so may be a good long-term investment as it will likely increase the longevity of your wires.
How to Secure Electrical Wires That Run Through the Attic
There are many approaches that you can take when securing electrical wires in your home, but when doing so in the attic it’s advised that you stick to some specific guidelines.
First and foremost, the wires must be secured to ensure maximum safety. If wires are exposed, hanging down from a structure, or laid out somewhere that they could be tripped over, this could be very dangerous.
The easiest way to secure the wires that run through your attic is by using staples.
Check out this YouTube video that shows you how to staple conduit.
Most attics have plenty of joists or wood studs that support the structure. These are ideal for securing the electrical wire, as they are very sturdy and are generally positioned out of harm’s way.
If you’re running the electrical wire parallel to the joists in your attic, you should staple it to the inner side of the wood.
A gap of around 2 or 3 feet between each staple should provide adequate security, but if you notice some of the wire sticking out, you can staple it with shorter gaps.
The electrical wire should remain at least one inch away from the bottom edge of the joist. This will prevent the wire from being damaged if any building work is done in the future, such as the installation of another structure or drywall.
If the wire is positioned too close to the bottom edge of the joist, there is a risk that a builder may not see it and put a nail through it, or damage it in some other way.
You may find it easier and more practical to run the wire perpendicular to the joists.
If this is the case, then the best course of action is to drill holes through the wood and run the cables through them.
Depending on the specific wire that you’re using, you’ll need to use a certain sized drill bit to make the holes.
In most cases, a ½ inch spade bit will be used for 14AWG NM electrical wire.
Here’s a table that shows the diameter and other attributes of different varieties of copper wire.
| AWG | Diameter (inches) | Ohms (per 1000ft.) |
| 10 | 0.1 | 1 |
| 12 | 0.0791 | 1.6 |
| 14 | 0.0633 | 2.5 |
| 16 | 0.05 | 4 |
| 18 | 0.0395 | 6.4 |
If the wire needs to bend, you should put a staple within 1ft of this point. The same method should be followed if the wire needs securing close to an electrical box.
I’d also recommend having no more than four 90-degree bends in the wire between junction boxes, and any holes that you make in the joists should be at least 2 inches away from the edge of the structure to avoid weakening them.
Providing you follow these tips, you should have no problems securing the electrical wire in your attic.
I have written a separate article on installing junction boxes in an attic. You can read it here.
Is Conduit Better Than Romex?
One common topic of discussion in the world of electronics is whether conduit or Romex is the best option for wiring. While both varieties have several strengths and weaknesses, the jury is out on which is better.
Firstly, conduit is more versatile than Romex. This is because when you use conduit, you can essentially create your color-coding system due to the wide range of available colors.
Romex, on the other hand, is only available in red, white, and black. This limits the options you have when connecting wires.
With conduit, you could use a pair of yellow wires to connect a switch to a light, without the need for a white wire.
With that being said, Romex is considerably more cost-effective than a conduit.
Electrical installation using conduit may cost around twice as much as a Romex installation. However, the flexibility it affords you is arguably worth the extra investment.
Another advantage that romex has over conduit is that it is generally quicker to install.
Many electricians claim that romex is easier to work with than conduit, but others argue that this is due to them not being as familiar with how the former is used.
Realistically, both conduit and Romex are effective providing they are installed properly and safely. Some electricians prefer to use one variety, but either will work for residential purposes.
How To Protect Wires in an Attic
In addition to securing any electrical wires that run through your attic, it’s important to adequately protect them. This can be achieved using simple tried and tested methods.
If your electrical wires run across the top of the joists in the attic, or are secured to any other structure, you should use guard strips for protection. These guard strips must be robust and substantial to ensure that the wire is preserved.
As a minimum requirement, the guard strips should match the height of the electrical cable in the attic. If you cannot access this area using a ladder or a permanent set of stairs, you are only required to protect the wire within 6ft of the entrance.
Guard strips are very easy to install. They provide a layer of protection to the electrical wire so that if it is stood on or something falls on top of it it won’t be damaged or dislodged.
Related Questions
What are the different types of electrical conduit?
Electrical conduit can be categorized into four main types. The first is known as RMC, which stands for the rigid metal conduit. Then there’s IMC – intermediate metal conduit. FMC is short for flexible metal conduit, and finally, EMT is electrical metal tubing.
What is the difference between electrical conduit and PVC?
PVC and electrical conduit are different colors. The former is commonly white, while the latter is grey. Also, PVC is commonly used for plumbing purposes rather than electrical applications.
How deep should an outdoor electrical conduit be underground?
Electrical conduits made from metal should be buried a minimum of 6 inches beneath ground level. This distance increases if you’re burying the conduit under a driveway, or a road.
