Re: Hole Diameter for running cable

["HLS" <henryhartley@xxxxxxxxxx>]

Robert Green wrote:
>
> Thanks.  I'm always reluctant to drill through joists and wonder whether
> some of the engineers here could suggest what size plywood "cladding" would
> offset the loss of structural integrity by drilling 2" holes in 8 or 10"
> joists.  I've been laying out a CCTV upgrade and with RG6 going everywhere,
> the holes add up.

I cannot imagine needing 2 inch holes to run these sorts of wires in a
home.  I'm assuming that these holes are in the floor joists in the
ground floor, meaning it is the unfinished ceiling of the basement.  Or
is this a house that's still under construction?  If it is still being
built assume an inspector will see the holes - make sure they meet to
code.  The code is generally not arbitrary.  Find out what it says and
either follow or exceed its requirements.  While building codes are
generally not published on-line, you should be able to find out what
code applies.  Then you could check to see if your local library has a
recent copy.  For instance, my county uses a slightly ammended version
of "International residential code for one- and two-family dwellings"
which our libraries have.

If it were my home (and it was, recently) I'd be inclined to drill 1/2"
holes somewhere near the ends of the joists.  That hole is large enough
for two, three or even four cables.  If I'm only running one cable, I'd
make it 3/8".  If you need to run a bunch though one stretch, you might
need to increase the hole size to as much as an inch but two inches
seems excessive.  If an inch isn't enough, then perhaps you need to do
a bit more planning.  Also, you're better off using a single cable with
more conductors than trying to fit a whole bunch of individual cables
in any particular run.

--
H