Why Run Ethernet Cable Instead of Using Wi-Fi
A wired Ethernet connection delivers faster speeds, lower latency, and more stable performance than Wi-Fi, regardless of how many devices are connected to the network.
Wi-Fi signals degrade with distance, pass through walls with varying levels of loss, and are affected by interference from neighboring networks, microwaves, and other wireless devices. A wired connection is not subject to any of these factors — the signal travels through copper wire from the router to the device with no degradation.
Ethernet is particularly important for tasks where network stability directly affects performance: remote work video calls, online gaming, 4K video streaming, large file transfers between computers, and always-on devices such as NAS storage systems or security cameras.
What You Need Before You Start
Running Ethernet cable through a house requires specific tools for drilling, fishing cable through wall cavities, and terminating connections at both ends.
Tools required:
- Stud finder — locates wall studs and, on advanced models, detects electrical wiring and pipes behind drywall
- Drill with spade or auger bit — for drilling holes through wall plates, studs, and floor joists
- Fish tape or fish rods — flexible tools used to guide cable through enclosed wall cavities
- Drywall saw — for cutting outlet-sized openings where wall plates will be installed
- Cable stripper and RJ-45 crimping tool — for terminating cable ends with connectors
- Voltage tester or wire detector — for identifying live electrical wires before drilling
- Measuring tape and pencil — for marking hole locations and measuring cable runs
Materials required:
- Ethernet cable (see cable selection section below)
- Wall plates with keystone jacks for each outlet location
- RJ-45 connectors for terminating cable ends
- Cable staples or clips for securing cable along exposed runs
- Low-voltage mounting brackets for wall plate installation
How to Choose the Right Ethernet Cable
The choice of Ethernet cable depends on the speed requirements of your network, the distance the cable needs to travel, and whether the cable will be installed inside walls permanently.
Cat5e supports speeds up to 1 Gbps at distances up to 100 meters. It is the minimum standard for a new installation and is suitable for general home use where gigabit speeds are sufficient.
Cat6 supports speeds up to 10 Gbps at distances up to 55 meters, and 1 Gbps at up to 100 meters. It has tighter wire twisting and better crosstalk reduction than Cat5e, making it the recommended choice for most new home installations.
Cat6a supports 10 Gbps at the full 100-meter distance with significantly better shielding against interference. It is the best choice for high-performance networks, but the cable is thicker and stiffer, which makes it harder to route through tight wall cavities.
For cables installed inside walls, look for in-wall rated cable marked CMP (plenum-rated, for air-handling spaces) or CMR (riser-rated, for vertical runs between floors). Standard outdoor or patch cable is not rated for in-wall installation and does not meet building code requirements in most jurisdictions.
Purchase 10–15% more cable than your measured route length to account for routing around obstacles, slack at connection points, and measurement errors.
Safety Precautions Before Drilling
Before drilling any holes, you must identify what is inside the walls — electrical wiring, plumbing pipes, and structural elements can all be damaged by a drill bit.
Turn off the electrical circuit for the area where you will be working at the breaker panel. Even with power off, use a non-contact voltage tester to verify that no live wires are present near your drill points before drilling.
Use a stud finder with wire and pipe detection capability to scan the wall surface before marking any drill locations. Mark the positions of studs, and avoid drilling within 1.5 inches of a stud edge, where electrical cables are often stapled.
If you suspect plumbing behind a wall, cut a small exploratory hole with a drywall saw rather than drilling blindly. Use a flashlight to inspect the cavity before proceeding.
In homes built before 1980, be aware of additional hazards: lead paint on walls, asbestos insulation, and knob-and-tube wiring that does not respond to standard voltage testers. If you are unsure about the age or condition of your home’s infrastructure, consult a professional before drilling.
How to Plan the Cable Route
Planning the cable route before drilling determines how much cable you need, where to drill, and which path avoids structural and electrical obstacles.
Start by identifying the source location — typically the router or network switch — and the destination in each room. Mark both points on a rough floor plan of your home.
There are three primary routing approaches, each suited to different home layouts:
- Through interior walls horizontally — the most direct route between adjacent rooms on the same floor. Requires drilling through wall plates (the horizontal framing members at the top and bottom of wall cavities) and navigating fire blocking inside walls.
- Through floors vertically — used when the router is on a different floor than the destination. Requires drilling through floor joists and locating a path between floors that avoids obstructions.
- Through attic or basement — routing cable up into the attic or down into the basement and then dropping down or up through wall cavities to each destination room. This is the least invasive method and avoids most in-wall obstacles.
Do not run Ethernet cable parallel to electrical power cables. Electromagnetic interference from electrical wiring can degrade signal quality on unshielded cable. Maintain a minimum separation of 6 inches from power cables, or cross them at a 90-degree angle if the routes must intersect.
Measure the full planned route including vertical drops, turns, and routing around obstacles. Add 10–15% to this measurement when purchasing cable.
Step-by-Step: Running Ethernet Cable Through Walls and Floors
Running Ethernet cable through interior walls involves drilling entry and exit holes, feeding the cable through the wall cavity using fish tape, and securing it at both ends with wall plates.
Step 1: Mark the Entry and Exit Points
At each room where a network outlet will be installed, mark the wall location for the outlet box — typically 12–18 inches above the floor, aligned with existing electrical outlets for a clean look. At the source end, mark the exit point near the router or patch panel location.
Step 2: Turn Off Power and Verify with a Voltage Tester
Switch off the circuit breaker for the affected area and confirm with a non-contact voltage tester that no live wires are present near your marked locations. Do not skip this step even when drilling low on the wall.
Step 3: Cut Outlet Openings and Drill Routing Holes
Use a drywall saw to cut the outlet-sized opening at each wall plate location. Then drill routing holes through the wall plates (top and bottom framing members) using a spade or auger bit. For vertical runs, drill through floor joists as needed. Keep the drill bit perpendicular to the surface to avoid deflecting into adjacent cavities.
Step 4: Attach Cable to Fish Tape and Feed Through the Wall
Connect the end of the Ethernet cable to the fish tape using electrical tape, folding the cable back on itself to create a smooth nose that will not snag on obstacles inside the wall cavity. Feed the fish tape from one opening toward the other, applying steady forward pressure. In longer runs, a second person at the exit point can help guide the tape through.
Step 5: Pull the Cable Through and Leave Slack
Once the fish tape exits at the destination opening, detach the cable and pull it through by hand until you have at least 12 inches of slack at each end. This slack is needed for termination and for future re-termination if a connector needs to be replaced. Do not pull the cable tight against the wall frame — leave a slight loop inside the wall cavity at each bend point to prevent stress on the cable jacket.
Step 6: Install Wall Plates and Keystone Jacks
Mount low-voltage brackets in each outlet opening. Terminate the cable into a keystone jack by following the T568B wiring standard — strip 1 inch of the outer jacket, untwist each pair only as far as needed, and seat each wire into the jack’s punch-down terminals in the correct color order. Snap the keystone jack into the wall plate and secure the plate to the bracket.
Step 7: Terminate the Source End
At the router or patch panel end, terminate the cable with an RJ-45 connector using a crimping tool, or punch it down into a patch panel port using the same T568B standard. Consistency in wiring standard across all terminations is essential — mixing T568A and T568B on the same cable run will result in a non-functional connection.
Step 8: Label and Test Every Run
Label each cable at both ends with its room destination before patching it in. Use a cable tester to verify continuity and correct pin mapping on each completed run before closing up any walls. A basic continuity tester confirms the connection works. A more advanced tester can verify speed capability and identify wiring errors by pin.
Alternative Routes: Attic, Basement, and Crawl Space
When running cable directly through walls is not practical — due to insulation, fire blocking, or structural obstacles — routing through an attic, basement, or crawl space is a cleaner and less invasive alternative.
Through the attic works well in single-story homes and for second-floor rooms in two-story homes. Cable runs horizontally across the attic floor between wall cavities, then drops vertically down through the top wall plate into the room below. This method avoids drilling through multiple wall cavities and is easier to route over long distances.
Through the basement or crawl space is the mirror approach for ground-floor rooms. Cable runs along the basement ceiling between joist bays and enters each room by drilling up through the floor and bottom wall plate. This is the most common method for structured cabling installations in finished homes.
Surface-mounted cable raceways are a non-invasive alternative when drilling into walls is not possible — in apartments, rental properties, or homes with masonry walls. Plastic or metal raceways attach to the wall surface along baseboards or door frames and conceal the cable without requiring any drilling. This approach is faster to install but more visible than in-wall runs.
Frequently Asked Questions
What is the maximum length for an Ethernet cable run?
The maximum recommended length for a single Ethernet cable run is 100 meters (328 feet) for Cat5e, Cat6, and Cat6a at gigabit speeds. Beyond this distance, signal quality degrades and speeds drop. For longer runs, a network switch or repeater is required to extend the connection.
Do I need to turn off power before running Ethernet cable?
Yes. Although Ethernet cable itself carries no mains voltage, drilling through walls without turning off the power risks puncturing electrical wiring inside the wall cavity. Turn off the relevant circuit breaker and verify with a non-contact voltage tester before drilling any holes.
What is the difference between T568A and T568B wiring?
T568A and T568B are two wiring standards for terminating Ethernet cable into RJ-45 connectors and keystone jacks. They differ in the arrangement of the orange and green wire pairs. Both work equally well — the critical requirement is to use the same standard on both ends of every cable run. T568B is the more common standard in North American commercial and residential installations.
Can I run Ethernet cable through exterior walls?
Exterior walls can be used for routing, but they present additional challenges: they typically contain insulation that obstructs cable feeding, and they may have a vapor barrier that should not be penetrated unnecessarily. If routing through an exterior wall is required, use a flexible drill bit to navigate around insulation and seal any penetrations with fire-rated caulk.
How do I get Ethernet cable from one floor to another?
The most practical method for floor-to-floor runs is routing through the basement or attic rather than drilling through floor joists inside wall cavities. Drop the cable from the attic into the top wall plate of the destination room, or bring it up from the basement through the bottom wall plate. This avoids drilling through multiple structural members and is easier to fish cable through.
How long does it take to run Ethernet cable through a house?
A single cable run between two adjacent rooms on the same floor typically takes 1–3 hours for an experienced DIYer. A full-house installation covering 4–6 rooms across multiple floors usually takes one to two full days. Professional structured cabling installation for the same scope is typically completed in one day with proper equipment.
When to Hire a Professional for Ethernet Installation
Ethernet installation becomes significantly more complex in multi-story homes, older buildings, or when the network needs to cover many rooms and support high-performance applications.
Professional installation is the better choice when: the home has multiple floors and no accessible attic or basement; walls contain masonry, concrete, or steel framing that requires specialized drill bits; the building is older and may contain hazardous materials; or the project requires a structured cabling system with a central patch panel, cable management, and documentation.
A professionally installed structured cabling system uses in-wall rated cable, properly terminated patch panels, labeled cable documentation, and tested runs — ensuring the network performs at rated speeds and meets building code requirements.
Lock & Tech installs structured cabling and Ethernet networks in residential and commercial properties across New York City. Our technicians handle full home runs, multi-floor installations, patch panel setups, and cable management for offices and apartments.
Contact Lock & Tech to get a quote for Ethernet installation at your property in NYC.
