How to Run Wire Through a Wall to Avoid Water Leaks

Tips for a trouble-free installation

Hidden water leaks caused by improper cable and phone line penetrations through the siding can cause rot and mold. Here's the right way to run the cable service.

By the DIY experts of The Family Handyman Magazine

Blocking water drips

TV and Internet signals are the only things coaxial cables should be bringing into your house, but improperly installed cables can let in water, which can lead to rot and mold. So the next time you’re trimming the bushes, take a quick look where the cable enters the house.

Cable should never run downward and directly into your house. Rainwater will adhere to the cable and follow it right into your home. Ideally, the cable should run upward and then in. If your cable was installed incorrectly, contact your service provider and voice your concerns. If the provider refuses to fix the problem, see if you can reroute the cable in order to gain a couple of feet. Try to avoid splices if you can. They can weaken your signal.

If you’re installing new cable, loop the cable before it enters the building. The loop will not only help shed the water but also provide extra cable in case a mistake is made inside.

A properly sized feed-through bushing will allow you to drill a slightly larger hole so you can fish the cable in without damaging it. Dab silicone caulk behind the bushing before pushing it into its final resting place.

Back to Top

Required Tools for this Project

Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.

  • Cordless drill
  • Caulk gun
  • 4-in-1 screwdriver
  • Drill bit set

Required Materials for this Project

Avoid last-minute shopping trips by having all your materials ready ahead of time. Here's a list.

  • Cable clamps
  • Feed-through bushing
  • Silicone caulk