I have been on jobs where interior concrete walls were firred out with 1 x 2's. We wired them with romex and carved out recesses at the box locations. We used nail plates where the romex went through or behind the firring strips. In between the firring strips, this left the romex very close to, and sometimes touching the sheetrock. We were always passed on rough in. I always wondered if there was a violation in doing this. Is the 1.25 only required at framing members?
3/4" firring strips & NM
- Thread starter monkey
- Start date
- Status
- Location
- New Jersey
- Occupation
- Journeyman Electrician (retired)
The 1.25" dimension is from the edge of the framing member. The NM can be run just under the sheetrock without protection providing the 1.25" from the framing member is maintained. 300.4(D)
mdshunk
Senior Member
- Location
- Right here.
in that aplicAtion I use 3M's SIFS
Buck Parrish
Senior Member
- Location
- NC & IN
If it is a 2"X2". Which is really a 1 1/2". I use a shallow 4" sq. metal box with a plaster ring on it. Bring the wire up the middle with three eighth one hole straps shot to the wall. I never had a problem.
We do it that way also with 2 x 2s, but if you re read my post I was asking about 1 x 2s which are only 3/4" thick. What do you do in this case?
ptonsparky
Tom
- Occupation
- EC - retired
What box are you going to use? Getting a 1/2' conduit into a 1 1/2" deep box with 3/4"firing & 1/2" rock will be a real pleasure.
mjf
Senior Member
fire rewire
fire rewire
Just completed a fire rewire where all the existing was romex run along 3/4" strips against block wall (like your scenario). Turns out all the home runs were stapled along the bottom of the ceiling joist which were also firred down 3/4". Not the whole house was fire damaged, but all of the walls and ceilings were gutted, so all wiring was exposed. The existing wiring may have been to code at one time, but not today. I made them frame exterior walls along the block and I drilled all the joist (atleast 1 1/4" from edge). I wound up rewiring 98% of the house.....there were 2 existing wires that were fine how they were. I asked my inspector what he would have done if I had left the existing wiring and he just shook his head and said "you know better than that".
fire rewire
Just completed a fire rewire where all the existing was romex run along 3/4" strips against block wall (like your scenario). Turns out all the home runs were stapled along the bottom of the ceiling joist which were also firred down 3/4". Not the whole house was fire damaged, but all of the walls and ceilings were gutted, so all wiring was exposed. The existing wiring may have been to code at one time, but not today. I made them frame exterior walls along the block and I drilled all the joist (atleast 1 1/4" from edge). I wound up rewiring 98% of the house.....there were 2 existing wires that were fine how they were. I asked my inspector what he would have done if I had left the existing wiring and he just shook his head and said "you know better than that".
Buck Parrish
Senior Member
- Location
- NC & IN
You would have to use a 10cu. in box. And make all splices in a j-box above.
Or like your op said. bust the wall.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Caddy CJ-6.
- Location
- New Jersey
- Occupation
- Journeyman Electrician (retired)
I agree, just silliness. And not only that some places may require insulation in finished basements to comply with the building code. Not much going in a 3/4" space.
We did a job a few years ago with an old time carpenter. He was using furring strips nailed to the walls with cut nails. A real crappy job IMO. We asked how he was going to get a box in the 1.25" space and he said that he would chop out the block wherever a device was to be installed. And he did.
- Location
- Massachusetts
Standard practice where I am, at least in multi dwelling buildings.
We have done a lot of large assisted living, condo, hotel type work and many time they shoot metal high hat on the block partition walls, we will have to blow holes out wherever a box goes. The one project where I was actually assigned on site for a while there was one helper who spent a lot of his time making the holes.
steelersman
Senior Member
- Location
- Lake Ridge, VA
The main reason I beleive for not using 2x4's is the room will be that much larger with just furring strips. But if it were my house I would not want it done that way. For one I would like my block wall to remain intact as much as possible and secondly I would want to be able to put adequate insulation in the walls.
Cavie
Senior Member
- Location
- SW Florida
You northern guys need to get out of the house more often. 3/4 furring strips on block walls has been a part of my daley life for about 38 years. That's how it's done in Florida. Before the 1.25 spacing came out we used to just staple to the side of the furring strip. After the change in the NEC we started buying the standoffs Mark mentioned. They come in plastic and metal. Just install a nail plate over any notches in the strips. There is no requirement to keep the wire from touching the drywall. The standoffs keep the wire away from the strip and out of the way of the dry wallers nails. the plates take care of the 1.25 requirement and stop the nails and screws. I don't know how to wire basements. Have never seen one. Guess I should get out more.:wink:
Guess I should get out more.:wink:
steelersman
Senior Member
- Location
- Lake Ridge, VA
Around here, some of the older homes were just furring strips with the block wall punched out for boxes, but as for all new basements I've seen everyone uses 2x4's. That's pretty much the norm.You northern guys need to get out of the house more often. 3/4 furring strips on block walls has been a part of my daley life for about 38 years. That's how it's done in Florida. Before the 1.25 spacing came out we used to just staple to the side of the furring strip. After the change in the NEC we started buying the standoffs Mark mentioned. They come in plastic and metal. Just install a nail plate over any notches in the strips. There is no requirement to keep the wire from touching the drywall. The standoffs keep the wire away from the strip and out of the way of the dry wallers nails. the plates take care of the 1.25 requirement and stop the nails and screws. I don't know how to wire basements. Have never seen one.
hillbilly1
Senior Member
- Location
- North Georgia mountains
- Occupation
- Owner/electrical contractor
I've used Wiremold and Wiremold boxes, Don't really know how legal it is, being concealed behind the sheetrock, but you have more room without having to bust a hole in the block, or even worse chisel out a hole in poured walls (Majority of basements down here are now poured concrete walls) No conversion problems unlike EMT due to low profile, but much more expensive. The shallow boxes with a MIDI or jumbo cover works fine.
- Status