# Wire through cinder block



## bobelectric (Mar 3, 2007)

You'll be ok with UF,not NM


----------



## nap (Dec 4, 2007)

you can put a sleeve through the block of either EMT or PVC conduit and then pass the NM through that. If the block is a firewall, you will need to caulk any openings with rated caulk. If not a fire wall, you can use any caulk.

What I would do is mount a junction box on each side of the wall with a length of EMT between the two boxes and use THWN wire to run from box to box. You can then run NM to the boxes and on to the rest of your branch circuit.


----------



## Red Squirrel (Jun 29, 2009)

I was thinking of using a small piece of conduit too, I might go that route. I will most likely do this on both sides, instead of running the wire inside the crawlspace to the next socket.


----------



## nap (Dec 4, 2007)

Both sides? You just run one continuous piece through the entire wall (block) so it is protected the entire distance. You might want to consider plastic bushings on the ends of the conduit to protect the NM from the conduit. I like these:

http://www.arlcatalog.com/EMT/Insulating%20Bushings.htm


----------



## Red Squirrel (Jun 29, 2009)

Actually I was not really clear, I meant both sides of the crawlspace, it is divided by a huge beam, so I need a light on both sides. Though the more I think about it, This is probably the best way to go about it (pic). What is the best way to mount the wire or conduit to concrete? Should I use pipe brackets with masonry screws, or is there a better way that has less risk of causing cracks?


----------



## nap (Dec 4, 2007)

I see.

for concrete, I like tapcons for fasteners and then, whatever type of strap that will properly hold the the conduit or nm.










for blocks, I prefer hollow wall anchors or AJ's as some guys call them. Typically for something like this, I would use anchors for 1/4-20 machine screws, and then, of course, a proper strap.









the problem with this type of anchor is the tool required to install them is somewhere around $35-$50. If you only use it once in a long while, it isn't worth using this system. 

I stay away from just a screw for blocks. They are not actually very hard or solid so a screw often pulls out.

A plastic anchor would work ok if there is no abuse to the pipe once in place.


----------



## Red Squirrel (Jun 29, 2009)

Plastic anchor might be my best route then. So would I drill a hole, put the anchor in, then screw into it same way as I'd do with drywall?


----------



## nap (Dec 4, 2007)

Red Squirrel said:


> Plastic anchor might be my best route then. So would I drill a hole, put the anchor in, then screw into it same way as I'd do with drywall?


drill hole

insert plastic anchor

place j-box, pipe strap, etc.

put screw through hole


twist until seated.

If you have a battery operated screw gun, that is the best way to install the screw. I have done them by hand and if only a few, it's ok. You need to be able to stop the rotation instantly and a battery screw gun allows that.


----------



## Red Squirrel (Jun 29, 2009)

Perfect, think that's going to be the easiest route, when I'm ready to do this I'll go buy the stuff needed. Will be nice to actually have some light in there.


----------

