Cable entry - air tight

skjom

Getting the hang of it
Jul 3, 2015
105
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I was wondering how to create an airtight cable entry system in concrete wall.

To allow for future expansion, let's say running 4 cables now but 20 in future.

The entry system should not reduce the airtightness of the house or the thermal property of the house.
 
Concrete usually requires core drilling.
Drill maybe 80-100mm diameter and then maybe cable junction boxes on each side of the wall that can be sealed off to maintain the air tightness.
 

These look handy
 
I was wondering how to create an airtight cable entry system in concrete wall.

To allow for future expansion, let's say running 4 cables now but 20 in future.

The entry system should not reduce the airtightness of the house or the thermal property of the house.

I’d say you wouldn’t have much to worry about really. Unless your pipe is a few metres in diameter, airflow and thermal exchange would be largely insignificant in a house. Maybe in a houseboat, but that would be water intrusion.

However, tape both ends of your pipe which is significantly longer than the wall thickness. Slather the pipe with hydraulic cement like DryLok or get the foundation crack sealing stuff (forget which brand is best). Slide pipe into hole and let cement set up. Use the small tubing of the crack filling kit to work it’s way around the pipe. You can cut a lengthwise groove top and bottom and a round groove around the midpoint of the hole to let the filler flow from bottom to top and out each end. Let set and harden.

Cut tape all the way back to near the now dry and airtight outer end of the pipe. You can use the airtight pipe grommets mentioned above now as well. It might cut down on rodent/insect entry. Leave enough of the pipe exposed to slide the end cap and/or elbow fittings and glue them to the pipe. If elbows, remember 2 45s instead of a single 90 degree. Or a junction box.

Look for the “flexible grommets” or “whisker grommets” for inside the pipe. The wiskers are like snow brush bristles that the wires will push through but disrupt airflow. The flexible grommets are more of a flexible rubber membrane that can stretch a bit. But going from 4 to 20 wires will likely need those changed.
 
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Any pictures of videos of what this looks like afterwards?

if you mean of what I described? Not really.

But each step has videos thanks to Google….

concrete coring
foundation repair
etc

There might even be an “This Old House” doing some of this…