i have no access to a nec publication, so i thought i'd ask
around until i can get a hold of one.
i purchased an old house (30's) and some of the wiring are
old (still on insulators). i don't like digging around for
cable under weather insulation. can i hang (from the roof
rafters) or suspend it from the joist?
the house is on pier and beam. i thought "floating" it
(vs stapling) will keep the wires from getting stretched
as the house/foundation moves.
All junction boxes should be attached to the structure. Any box for
"hanging" fixtures needs to be rated for that purpose.
Any hanging fixture usually comes with a chain or support device that is
attached to the structure either directly or through the rated support box.
If the home is circa 1930's it is time to think about a complete electrical
upgrade, service and all wiring. Way back then there were no ground
conductors (usually) and the newer electronic devices like to be grounded.
Not sure what you mean by "floating" but code requires that cables be
stapled properly. If by "floating" you mean "sagging", then No.
Generally code prohibits running cables unprotected on the bottom of
joists and rafters. If the space is one that will never be finished,
like a crawlspace, it should be ok to nail "running boards" to the
joists and then staple the cables along the boards. In attics you may
be restricted to areas of low height, like less than four feet or so. I
believe it's never ok to run cables along the tops of ceiling joists in
Otherwise the "right" way is to drill holes in the joists and pull
cables through them. The holes need to be a certain distance from the
edges so if someone ever attaches a ceiling or floor (or a new roof on
the rafters) the nails won't reach the cables. If you've got knob and
tube, someone's already done a lot of drilling (maybe with a brace and
bit, something to think about as your cordless drill purrs along) and
usually the holes are the right size and in the right place. Of course
you've got to remove the wire and the tubes first.
See if your big-box stores have a book that shows the code simplified.
Around here HD carries one called "Electrical Code Simplified" by P.S.
Knight; specific versions are published for each province. I would
assume something similar is available in the States. You'd want one as
specific to your jurisdiction as possible.
this is meant (attempt anyway) to respond to those that replied.
i had thought about the running board. but am not sure if i can suspend
it (yes, with support/straps vs stapling). basically all i was thinking
was to have easy access to the wires and not have them buried under
yes, a few of the circuits were new runs ("modern" cables). but, some
that go to light switches etc are still on knobs and tubes. so, they
are definitely going to go.
i'll do a running board instead, and clear out the insulation along
side it to provide access.
not sure where you are, but Can ele. code says:
" cable shall not be run on or across:
a) upper faces of ceiling joists or the lower faces of rafters in attic or
roof spaces, where the vertical distance between joists and the rafters
if it is more, you must use a running board.
this should answer it.
also, if the rafters are engineered wood, do not drill trhough them (they
should not be in house from 30's)
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.