How do I run Ethernet cable through the walls?
Use paths that already exist: a basement, crawlspace or attic into the wall, then a small drywall opening for the jack. Fish the cable with a fish tape, keep it away from household power wiring, and never share a box with it. Anything needing new holes in framing, fire-rated walls or runs beside line-voltage wiring is a job for a licensed pro.
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By Kasra Taheri, Founder, LoclisPublished
Researched and drafted with AI, then checked claim by claim against the sources listed below before it was published. Prices and rules change; the dates beside each source say when it was last checked.
Step by step
Read when to stop and call a pro, further down this page, before you start.
Step 1: Choose the central spot
Pick one location for the router and switch, then mark every room that needs a jack and plan one cable from each back to that spot.
Step 2: Find existing paths
Look for stacked closets, an unfinished basement ceiling or an attic hatch that gives cable a route without new holes in framing.
Step 3: Check the length
Keep each run one unbroken cable; a house-sized run is within the 100-metre channel length Siemon describes for its cable.[1]
Step 4: Keep clear of household power
Route away from outlets, switches and their cables, never share a box with line-voltage wiring, and note any plenum or fire-rated wall.[2]
Step 5: Open the wall for the jack
Mark the jack location with a stud finder and cut the opening in drywall for a low-voltage mounting bracket.
Step 6: Fish the cable
Feed a fish tape or pull string along the route, attach the cable and pull steadily within the cable maker's tension and bend limits.[1]
Step 7: Label and leave slack
Label both ends with the room name and leave some slack at each end.
Step 8: Terminate the jack
Fit the keystone jack and wall plate following the instructions that come with the jack.
Step 9: Test every run
Check each cable with a cable tester, or plug in a laptop and confirm the link speed.
Run the cable through paths that already exist: from a basement, crawlspace or attic down or up into the wall, then out through a small opening cut in the drywall for a wall jack. Pull it with a fish tape or pull string, keep it well away from anything that carries household power, and never share a box with it. If the route needs new holes through framing, passes near line-voltage wiring or crosses a fire-rated wall, that is where a licensed pro takes over.
Plan the route first
Start with the endpoints. Pick the room where the router and switch will live, usually a closet, utility room or basement wall, and mark every room that needs a jack: the office, the TV, a Wi-Fi access point on the ceiling or the top floor. Run one cable from each jack back to that single spot, not from jack to jack.
Look for a path before you look for a cable. Two floors with a closet stacked above another closet, an unfinished basement ceiling under the room, and an attic hatch over a hall are the easy routes. Mark them on a rough floor plan, and keep the plan: it is also what you hand to a contractor if you change your mind.
Length matters too. Siemon's spec sheet for its Category 6A cable describes a channel built for 10GBASE-T operation over 100-metre, 4-connector topologies,[1] so a house-sized run is well inside the limit. Keep each cable in one unbroken length from jack to the central spot.
Stay clear of household wiring
Ethernet cable is low-voltage, and the building code treats it differently from household power. Virginia's Uniform Statewide Building Code exempts installation of wiring and equipment that (i) operates at less than 50 volts, (ii) is for broadband communications systems,[2] from needing a permit, but not when the installation is in a plenum or penetrates fire rated or smoke protected construction.[2] A plenum is a space that carries air for heating and cooling.
In practice that means three rules for a homeowner. Keep the cable away from outlets, switches and the cables running to them. Do not put an Ethernet jack in the same box as an outlet or switch. And if you find you must cross a wire, cross it at a right angle rather than running alongside it.
Handle the cable gently
Network cable is easier to damage than it looks. Siemon lists a maximum pulling tension of 110N (25 lbf) and a minimum bend radius of 27mm (1.1 in.) for its Category 6A F/UTP cable,[1] and other cables have their own limits, so check the spec sheet for the cable you buy. Pull steadily, never yank, and avoid kinks and tight corners. A damaged pair may still link at a lower speed and be mistaken for a bad router.
The same sheet gives an installation temperature of 0 to 60°C (+32 to 140°F),[1] so do not pull cable in an attic on a freezing morning.
Finish and test
Leave a little slack at each end, label both ends with the room name, and terminate with a keystone jack and wall plate, following the instructions that come with the jack. Then test every run, with a cheap cable tester or by plugging a laptop in at the jack and checking the link speed. Most "mystery" problems show up here, before the drywall is patched.
Stop and call a pro if
- The route needs a new hole through a stud, plate or joist, or any change to framing.
- The cable would run near or alongside line-voltage wiring, or share a box with it. That is the line between a low-voltage job and an electrical one.
- The cable passes through a fire-rated or smoke-protected wall or ceiling, such as the wall between a garage and the house, or through a plenum, which the building code treats differently.[2]
- You are not sure what is behind the wall, or the house has plaster, brick or old insulation that blocks the way.
- Someone is paying you or you are paying someone for cabling worth $1,000 or more. The Board for Contractors says a valid Virginia Contractor's License is required for work valued at $1,000 or more.[3] Cabling is a specialty of its own: the Board defines it as the installation of systems that operate at 50 volts or less, including computer cabling and data and network installation.[4]
Getting help in Virginia
For costs, read what it costs to wire a house for Ethernet in Virginia and whether to hire a low-voltage contractor. If the real goal is Wi-Fi in every room, see whole-house Wi-Fi costs. Browse security and smart home pros or more smart home answers.
When the route is more than you want to take on, describe your cabling job once and licensed local pros quote it.
Common questions
- Which Ethernet cable should I run in the walls?
- Solid-copper Category 6 or 6A is the usual choice for a new house run, because it supports gigabit speeds and, in the 6A case, 10GBASE-T over a full 100-metre channel according to Siemon's spec sheet. Check the cable's own datasheet for its pulling-tension and bend limits before you buy.
- Do I need a permit to run Ethernet cable in Virginia?
- Usually not. The Uniform Statewide Building Code exempts wiring and equipment that operates at less than 50 volts and is for broadband communications, but not when it is in a plenum or penetrates fire rated or smoke protected construction. Ask your local building department if you are unsure.
- Can I run Ethernet next to electrical wires?
- Avoid it. Keep the cable away from outlets, switches and their cables, cross a power cable at a right angle if you must, and never share a box with line-voltage wiring. If the only route runs alongside household wiring, hire a licensed pro.
- How tight can I bend Ethernet cable?
- It depends on the cable. Siemon lists 27mm (1.1 in.) as the minimum bend radius for its Category 6A F/UTP cable, and other makers list their own. Avoid kinks and sharp corners, and check the spec sheet for yours.
- Is it cheaper to run cable myself?
- Often, if the route uses existing paths. Cabling through finished walls and fire-rated construction is where the time goes, and where a pro earns the fee. See the cost answer for what a quote covers.
Sources
- [1] Spec Sheet, Category 6A F/UTP 4-Pair Cable, Siemon. Checked October 27, 2026.
- [2] 13VAC5-63-80, Section 108 Application for permit (Virginia Uniform Statewide Building Code), Virginia Administrative Code, Virginia General Assembly. Checked October 27, 2026.
- [3] What You Should Know Before You Hire a Contractor, Virginia Board for Contractors, DPOR. Checked October 27, 2026.
- [4] 18VAC50-22-30, Definitions of specialty services, Virginia Administrative Code, Board for Contractors. Checked October 27, 2026.
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