Stopping Air Infiltration at Cable / Phone Line Entry

This is an entry point for cable TV coax, phone lines and a couple of grounds. They exit the basement of this home through a hole drilled in the foundation.

The air infiltration at this opening is significant. There is effectively a open path to the outside between every cable. If you flex the cables a bit you can see sunlight.


I'm struggling with how to stop the airflow. My first thought was expanding foam but that could be a mess and not guarantee that the leaks would be filled.


I searched the web but mainly came up with industrial products for outdoor utility boxees.

Any suggestions?


Thanks for your help,




Johnny on Energy - Helping you improve your home energy efficiency.

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Gosh, that's a lot of wires.  If there weren't quite so many, I'd suggest making a foam gasket so that each wire passed through its own hole.


How about if you attached a zip tie to the bundle of wires on one side of the wall to immobilize them, and then on the opposite side peeled the wires apart one at a time and injected caulk between them, then bundled them back together (squishing the caulk) and zip tied that end?  That would seal all the gaps between wires, leaving you with only the outside of the bundle to seal.  Of course, getting any wires in or out after that would be nearly impossible.


Looking forward to hearing other people's suggestions.

With access like that, I'd try pushing into gaps appropriate lengths of wooden dowel of various diameters, to function like shims and fill those gaps.  Clean and reversible.  If it doesn't work, pull them out and try another's suggestion.


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