Interior exterior walls that are furred out with 7/8" furring strips

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infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
Furring strips takes me back to the fifties, and do it yourself jobs.

I agree, a method that should have expired years ago when Chanel and Rickels went out of business.

If you had an inch and a half,,,,you could have flush mounted it,,,,why was it sticking out?

What kind of box would you use with only 1.5" distance between the finished surface and the wall?
 

hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
I have used wiremold boxes, they just shallow enough, but are wider than a standard UT box, so you get more wire fill space. A midi or jumbo cover will cover the hole if its cut right. Only problem is they are probably not rated for concealed use.
 

macmikeman

Senior Member
Talk the builder into turning wood 2x2 or 2x4's on edge for furring and leave you a horizontal gap just wide enough for wiring method that allows for a nail plate to cover the gap. Hilti gun shoots wood to block as well as it does hat channel. Mount either 1-1/2" deep 4 sq metal box with 1/2" rings or use carlon non mettalic 1-1/2" x 4" boxes with 1/2" non metal rings. You will be flush after sheetrock is installed. Easier for him and you to work with than hat channel. If he won't do anything like that, a tile bit in a rotozip cuts block knockouts fast as long as the user knows how to use a rotozip without dulling the bits every 10 seconds.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
Mount either 1-1/2" deep 4 sq metal box with 1/2" rings or use carlon non mettalic 1-1/2" x 4" boxes with 1/2" non metal rings. You will be flush after sheetrock is installed.
Just an aside note: I have found that a 5/8" ring works better for 1/2" drywall, 3/4" for 5/8" drywall, etc.

Making the ring 1/8" deeper allows room for the 8-32 screw heads, and holds the devices more firmly.
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
Gluing sheetrock does not exempt you from putting receptacles on that wall,,,,,It's still a wall line.
Your comment caused me to see the ambiguity in the description in the OP:
I'm working on a new project where the GC wants to fur out the exterior walls . . .
I read "new project" and understood work in an existing dwelling. That is how I framed my comment.

In my experience, in the jurisdictions I've worked it, the existing construction has to be open to framing for 50%, or more, of the wall area of any given room before the local ordinance claims that the current version of the NEC is invoked for that single room. The result, in my experience, is that skimming an existing wall surface with rock is one way for a GC to dodge upgrading mechanicals, electric, insulation, etc.

Now, if the OP means "new masonry wall" in a "new construction project", then your point is accurate.

Perhaps Lee Graves can offer an update and clarification?
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
In my experience, in the jurisdictions I've worked it, the existing construction has to be open to framing for 50%, or more, of the wall area of any given room before the local ordinance claims that the current version of the NEC is invoked for that single room.
Interestingly, the 50% rule is applied globally to the entire premises by floor area here.

One might get around it by doing a remodel in stages, but you didn't read that here. :cool:
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
50% of the "floor area"? How is it phrased? I'm not getting it.
If you have a 2500 sq.ft. building, and you renovate 1250 sq.ft. or more, the entire premises must be brought current for all trades: us, plumbing, HVAC, floor-spans, insulation, etc.

Truthfully, and not from a trade's perspective (okay, not only from that), I think it's a great idea. It's easy to bury dangerous flaws in a new skin, as others here have seen and heard.

I can find the legalese if you really want to see it spelled out.
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
I can find the legalese if you really want to see it spelled out.
:smile:
Thanks, Larry. Your paraphrasing it in what is probably a "customer friendly" turn of language is just fine, for my purposes.

What I stated is a similar turn of phase, that is, less legalistic. . . at least I hope it is.

The jurisdicitional variation in the approach to improving existing occupancies is interesting.
 

iwire

Moderator
Staff member
Location
Massachusetts
Furring strips takes me back to the fifties, and do it yourself jobs.

I agree, a method that should have expired years ago when Chanel and Rickels went out of business.

As I said pretty common around here and these are no DIY projects.

This is the last one I was personally involved with.


Sakonnet Bay Manor

From ground to top each units exterior walls are CMUs, the insulation is on the exterior of the CMUs under the fancy facade.

On the interior of the CMUs steel high hat track was shot onto the wall.


What kind of box would you use with only 1.5" distance between the finished surface and the wall?

We send a helper around to blow out the CMU wherever boxes will be, then we use a 4" sq with raised ring. Yes it is a pain and is more work for us.
 

chris kennedy

Senior Member
Location
Miami Fla.
Occupation
60 yr old tool twisting electrician
Every new home here is CBS (concrete block system) with furring on the exterior walls, along with most commercial buildings, no big deal.

Bob, what does CMU stand for.
 
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