In-Wall Cable Rating
A cable that goes inside a wall has to be rated to be there, and the rating is printed on the jacket. Every other property of the cable is secondary to that one line of text.
The marking itself
In-wall rated cable carries a marking such as CL2 or CL3 printed along the jacket. The marking describes the jacket, not the picture: it is about how the cable behaves as part of a building, not about bandwidth, connectors, or resolution.
A cable with no such marking is not an in-wall cable, no matter how well it performs on a shelf. Speed ratings and jacket ratings answer different questions, and one has never implied the other.
Local requirements
What is required for cable inside a wall is decided where you live, and it is not the same everywhere. Check what applies at your address before anything is cut, and check it with the authority that actually decides, not with a summary.
Nothing on this site states a requirement for any location, names a code, or interprets one. That is deliberate. A page cannot know which rules cover your building, and a wrong answer here would be worse than no answer.
Power, kept out
A signal cable in a wall cavity does not share that cavity with mains power. A factory power cord does not go inside a wall at all, in any cavity, for any distance, regardless of how neat the result would be.
If the plan you are drawing needs power to arrive somewhere it currently does not, that part of the plan belongs to an electrician. Where the screen sits is your decision. Where the current comes from is not.
Before the first cut
Measure the whole route first, from the connector at one end to the connector at the other, including the drop inside the cavity and the slack you will want at each plate. A cable that arrives one foot short inside a closed wall is a second hole.
Then plan for the cable to be replaced. Standards move, and the run that is adequate now is the run somebody has to pull out later. A conduit or a smooth path makes that a job; a stapled cable makes it demolition.
The surface route
A surface raceway keeps the cable outside the wall, visible, and replaceable in ten minutes. It looks like less of an achievement and it removes the entire question this page is about.
For a rented room, a wall you do not know, or a run you expect to change, the surface route is the one that does not need a rating, a permit conversation, or a second person on a ladder.
Stated and not stated
The left column is what a listing can tell you. The right column is what only your wall and your local authority can, and nothing on this page substitutes for either of them.
Stated
- The in-wall rating, on the listings that carry one
- Bandwidth in Gbps
- Length
- Connector type at each end
Not stated
- Jacket diameter and minimum bend radius
- What is required for in-wall cable where you live
- What is already inside your wall cavity
- Whether the run needs a wall plate at each end
- How much slack the cavity will let you leave
Common errors
| Error | Consequence | What to do |
|---|---|---|
| Reading a high bandwidth figure as permission to go in the wall | A cable with no jacket marking ends up sealed inside a cavity. | Look for the in-wall marking on the jacket and the listing, separately from the speed figure. |
| Measuring the wall face instead of the cable route | The cable is short by the depth of the drop and the slack at both plates. | Measure connector to connector along the actual path, then add slack at each end. |
| Running the power cord up the same cavity to tidy the wall | A factory cord ends up inside a wall, where it was never built to be. | Leave power outside the wall entirely and have an outlet added by an electrician if you need one higher up. |
| Stapling the cable so it cannot move | Replacing the run later means opening the wall rather than pulling a cable. | Leave the path smooth so the next cable can be pulled through it. |
Before starting
Stop
Only a cable marked with an in-wall rating on its jacket goes inside a wall. If there is no marking, it does not go in the wall, whatever the listing says about speed.
Stop
Never run a mains power cable or a factory power cord inside a wall, and never in the same cavity as a signal cable. If the plan needs power in the wall, hire an electrician.
Stop
Requirements for cable inside walls differ from place to place. Check what applies where you live before anything is cut. Nothing on this site states a requirement for any location.
Note
If you cannot tell what is inside the cavity, whether that is wiring, pipes, ductwork, insulation, or fire blocking, stop and get someone who can. An unknown wall is not a media project.