Our home remodel includes expanding the kitchen by about six feet,
enough to add a good-sized island as a workspace and to define the
dining area. We'd like to add power to the island, with outlets for
The island will sit on an existing concrete slab floor. My question is
whether it's feasible to trench the slab with a concrete saw from the
service panel to the island, lay conduit in the trench, pull conductors
through the conduit, then patch the trench with fresh concrete. (We're
replacing all flooring in the kitchen anyway, so there's no issues with
I'm guessing the trench will be about 2" deep, 2" wide, 8 ft long
before reaching the wall nearest to the service panel. Our slab is 4"
thick not including footings. Any danger of weakening the existing
Any issues with burying wire permanently in the floor like this?
I have a friend who has (well had) poured floors of concrete in his
old house... come to think of it, in his new house (which we joking
call the bunker.... the whole thing is concrete) as well.
We had a heck of a time drilling through it (from the basement) to run
electricity for a garbage disposal.
Had a masonry bit, but just a regular drill... hammer drill might have
With no crawlspace, you have limited ways to go.
Trench as OP mentioned(if it's allowed by code)
Raised floor (if it didn't present too many other problems)
Drop from above.
Wish I could add more... but i'm not a pro.
Ich habe keine Ahnung was das bedeutet, oder vielleicht doch?
Will the island have structures of any kind, like a cabinet above it?
Anything which might give you a post which could be hollow, through which
you could run conduit to the ceiling?
As far as grooving the slab, I see no reason why that couldn't be done. Just
check with your local building inspector for code regulations. Sometimes,
just reading the code can give you ideas for good ways to achieve your
purpose. Granted, codes are full of "thou shalt not", but they also contain
"thou oughta consider this idea".
I think that you will find that it will be much easier to remove the
concrete if you make your cuts all the way through the concrete, then just
smack the concrete with a sledge hammer a couple of times in 3 or 4 spots.
Once the first piece is pried out it's all downhill.
I agree with Volts. Go down to the full thickness of the slab. Don't remove
any wire mesh from the trench as you will want that to help the new concrete
tie in with the old.
You can use PVC conduit underground, but I always suggest stubbing up
through the concrete with a rigid metal elbow. The point where the conduit
emerges from the concrete is always the most vulnerable to abuse and
consequently breaks after a few years. You can mount a junction box on the
rigid stub-up and convert to non-metallic or armored cable to facilitate the
installation of receptacles throughout the island. You can also adapt the
rigid elbow to EMT for better protection of the wires in the island.
Table 300.5 in NFPA 70 can provide some insight.
Look at FCC (flat conductor cable). It is wide, but thin copper
conductors that are attached (glued) to your slab and the floor
covering, tile, carpet, etc. is then placed over it. FCC is available
in 12 and 10 gauge (20 or 30 amp capacity). The stuff isn't free but
it is a lot better than trenching in concrete. I've had several of
these installed in my conference rooms to bring substantial power for
large projectors and other equipment to large conference room tables
located in the center of the room. As I recall the last ones I signed
off on came from Hubbell.
A quick Google search only yielded this but they do exist and work well.
I didn't think FCC cable was used much anymore. I spent a few years on my
knees with that stuff in one office building that I serviced. The whole
building was wired that way. Mostly Thomas and Betts. It's expensive and
has specific code requirements for the installation. For instance, the
floor covering must be removable tiles that cannot be larger than 36"
square. It is not approved for residential use. The floor base must be
extremely smooth as any dimples or bumps can cause damage to the cable. It
is also available for data and phone wiring. I would only recommend its use
as a last resort.
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.