There are several reasons you may need to run a cable through exterior siding. Installing an outdoor security camera, wiring landscape lighting, connecting a hot tub or other exterior appliance, and adding an outdoor electrical outlet all require running cables through siding. While it may seem daunting, with the right tools and technique, running cables through siding is a straightforward DIY project.
The key steps are choosing the cable path, drilling holes through the siding, running cables, sealing holes, and securing cables. With proper planning and care, you can install new low-voltage wiring while maintaining the integrity and aesthetics of your home’s exterior.
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Should You Go Through Siding or Use Conduit?
When running new exterior wiring, you have two main options:
- Running cables directly through holes drilled in the siding
- Running cables through exterior-rated conduit attached to the surface of the siding
Here are some factors to consider when deciding on an approach:
Through Siding
- More aesthetically pleasing, as conduit is not visible
- Requires drilling holes in siding
- Cables may be subject to more exposure and damage
- Best for low voltage wiring like landscape lighting and security cameras
Surface Conduit
- No holes required in siding
- Conduit is visible on exterior walls
- Wiring is more protected inside conduit
- Easier for inexperienced DIYers
- Better for higher voltage wiring like exterior outlets
In general, low voltage wiring can safely run directly through siding, while higher voltage cables like those connecting an electrical outlet should be protected in conduit.
Choosing a Cable Path
Once you decide to run cables directly through the siding, some planning is required to choose the optimal route:
- Run cables as vertically as possible to avoid angled holes that allow water intrusion.
- Follow studs whenever possible, as this provides solid attachment points.
- Choose an interior wall location that avoids plumbing, wiring, and insulation.
- Electrical codes require exterior cables be at least 8 feet above ground level.
- Pick an accessible area you can easily work on and reach the interior outlet or fixture.
- Blend the cable route into architectural features to hide it.
If running multiple cables, leave at least 2 inches between them. Measure twice before drilling to ensure your cable path is optimal.
Drilling Holes Through Siding
Once you’ve mapped the route, you’ll need to drill holes through the siding. This requires:
- High-quality drill with sharp twist or auger bit, rated for siding materials
- Eye protection
- Vacuum to capture siding debris
Follow these best practices when drilling holes:
- Drill slowly and carefully to avoid cracking siding.
- Keep drill bit perpendicular to siding to minimize larger holes.
- Start with a smaller pilot hole, then increase to the desired diameter.
- Place a wood block behind siding when drilling to prevent splintering.
- If drilling through exterior cladding into sheathing, stop before drilling into house wrap or tyvek.
- Vacuum up debris during drilling to keep work area clean.
Hole diameter depends on the number and type of cables:
- Security camera: 5/8 inch hole.
- Landscape lighting: 1/2 to 3/4 inch hole.
- Electrical outlet: 1 1/4 inch hole.
Allow a 1/4 inch gap around cables for sealant. Avoid oversized holes that require excessive sealing.
Running and Connecting Cables
Once holes are drilled, run cables from the interior connection point to the exterior fixture. Take care not to damage the jacket or insulation while pulling wires through the hole. Use grommets, conduit, or cable clamps when passing wires through metal studs to prevent damage.
Leave 8 to 12 inches of extra cable at each end. Connections depend on the cable type:
Security Camera Cable
- Typically RG59 coaxial with BNC or RCA connectors
- Crimp or twist-on connectors attach to pre-installed cable ends
- Keep connections dry inside a weatherproof junction box
Low Voltage Landscape Lighting
- Two-conductor low voltage cable
- Use gel-filled wire nuts for connections
- Seal connections with silicone or electrical tape
- Keep junctions out of direct moisture
AC Power Cables
- Sheathed multi-conductor cable
- Attach to receptacle with cable clamp
- Use proper gauge cable for expected amperage
- Keep connections inside weatherproof exterior boxes
Take time making solid, weather-resistant connections to avoid issues down the road.
Sealing Holes and Securing Cables
The final steps involve sealing holes and securing cables. This helps restore the integrity of the siding and prevent moisture intrusion.
Sealing Holes
Use silicone caulk, exterior polyurethane sealant, or silicone rubber sealant to seal around cables. Look for weatherproof varieties that maintain flexibility long-term. Apply a generous bead and smooth with a finger or caulk tool. Other tips include:
- Clean and dry the area thoroughly before sealing
- Consider backer rod for larger holes to reduce sealant volume
- Wear gloves to smooth sealant
- Seal from both interior and exterior sides for best results
- Paint sealant to match siding if desired
Take the time to properly seal holes to prevent water ingress and damage.
Securing Cables
Finally, secure cables to provide strain relief and keep them organized. Options include:
- Cable staples
- Plastic wire clips
- Zip ties
- Electrical tape
Attach cables neatly at regular intervals along the route without overtightening. Excessive tension can damage cables over time.
Safety Tips
Observing basic safety measures helps prevent injury and damage:
- Turn off relevant breakers and disconnect power sources before working.
- Use a non-contact voltage tester to confirm power is off.
- Wear eye protection when drilling.
- Work slowly when drilling to avoid damaging siding and tools.
- Do not attempt to cut or drill into electrical boxes and meters.
- Have help available for long cable runs through walls.
- Use proper sealants and adhesives to avoid toxic fumes.
- Confirm cables are secure and not exposed before restoring power.
Rushing the job or skipping safety steps risks damaging the home, cables, and electronics.
Conclusion
While it requires care and effort, running cables through exterior siding is a job an ambitious DIYer can tackle. Following a careful process from choosing a route to sealing holes will allow you to safely install new low-voltage wiring that functions reliably for years. Pay attention to details like drill technique, weatherproof connections, and generous sealing to prevent moisture issues down the road. With the right materials and patience, you can add new exterior electrical features while maintaining the look and integrity of your siding.
| Cable Type | Typical Use | Drill Bit Size |
|---|---|---|
| RG59 Coax | Security Camera | 5/8 inch |
| Low Voltage | Landscape Lighting | 1/2 to 3/4 inch |
| AC Power | Exterior Outlet | 1 1/4 inch |
| Safety Item | Purpose |
|---|---|
| Eye Protection | Prevent eye injury from debris when drilling |
| Gloves | Protect hands from sealants and sharp edges |
| Voltage Tester | Confirm power is off before working |