Spray Foam Insulation and running wires

[Bryce_H]

Not sure if this is in the right place...

So we are moving into a new build house and it has a room dedicated to as a "media room" that is pre-wired for 5.1...in the wrong orientation. The room is 9X18 (I will have to treat for the room modes) and it currently is wired for the screen to go on the 18' wall. I want to change the orientation so the screen goes on the 9' wall. It is on the 2nd floor with the attic above, so I figured I would get up in the attic and run the wires up there and drill in drops for the 5+ speaker locations. Basically drill through the wall top plate from the attic and drop speaker wire down the wall, then fish it from a hole in the wall near the floor. I would also run HDMI for the projector.

However, it dawned on me that 2 of the walls are exterior and filled with spray foam insulation. Anyone have experience in running wires through spray foam insulation?

Once I get the all the wires run, can I then fill the other two interior walls with spray foam insulation (i.e. drill access holes from the attic through the top plate and fill it up...??) to help with sound isolation from the rest of the house.

Any info is appreciated. Thanks.

 

[Rickster71]

It's doable, just not as easy as an open bay.
Something like this: https://www.kleintools.com/catalog/flex-bit-augers/flex-bit-auger-34-19-mm-x-72-1829-mm Greenlee makes them too: http://www.homedepot.com/p/Klein-Tools-Flexible-Drill-Bit-Kit-3-Piece-53721/203913339
One issue, you'll have to use speaker wall plates and mount them higher than preferred, since the bit is 6' long and you have 9' ceilings and 3" for top plate.
I'd cut the hole for the wall plate and drill 'up' from there. Since it doesn't matter where you come out on the upper plate.

 

[Bryce_H]

That seems like a good approach. Apparently you can buy a 54" extension to the 72" kit - this gets me 10' 6" total which should work. Also like the idea of going up rather than down...