New store - "old work" - Holdzit straps?

Status
Not open for further replies.
B

bjp_ne_elec

Senior Member
Location
Southern NH
Looked at a new commercial store, but the issue is it's already sheet rocked, and the guy leasing the store wants a bunch of new receptacles in the already finished walls. Really not liking the idea of putting "old work boxes in a brand new place. Anyone else have any better ideas?

I was actually thinking of cutting in old work boxes, but cutting out the sheetrock in front of the stud and using Caddy clips designed to hold boxes on the edges of the metal studs. Not really liking the thought of old work boxes and Holdzit straps.

Haven't bought MC cable in a while, as I was thinking of using MC on this job. Anybody know what a 250' roll of this has been going for? This store has 12' ceilings - not sure why the owner put 14' ceilings in. Know I need to buy some 12' step ladders - this "going in to the EC business is getting pricey. (Not sure, for those reading this, that I've had other posts - and I'm just getting a business started. Quite a different experience than "just doing the work".

Thanks


Brett
 
old work boxes are made just for this situation.

it is unlikely anyone will ever notice much difference.

good luck in your new business.

never forget the important thing is to make a profit. all the neat new toys are meaningless otherwise.
 
bjp_ne_elec said:
. . . this "going in to the EC business is getting pricey. (Not sure, for those reading this, that I've had other posts - and I'm just getting a business started. Quite a different experience than "just doing the work".
Click to expand...
You ain't seen nothin' yet!

The best of luck to you.
 
I agree. Use old work boxes.
Last time I checked, 12-2 MC was about $128 at Home Depot, $140 at the supply house.

John
 
JES2727 said:
I agree. Use old work boxes.
Last time I checked, 12-2 MC was about $128 at Home Depot, $140 at the supply house.

John
Click to expand...

And if you're using MC, I suggest metal old-work boxes with box supports, and a 90-deg. flex connector in the back KO of the box.
 
Larry - which box supports are you referring to? I like your suggestion about the 90 degree connectro - I had that same idea back several years ago, and had forgotten about how much easier it was until you mentioned it.

Thanks,

Brett
 
We use MC and metal switch box listed for use with MC, to support the box we use madison straps, neat and easy installation, reason we don't use a 90 connector in back of box is for one, the connector would be buried, and it places entry of wiring behind recpt. which can be a problem if using commercial grade recpt's.
 
I agree with the others that pointed out a code violation installing 90 degree connectors in the wall.

I would use deep metal old works with MC clamps. Cut the hole tight and make sure you are gentle enough not to cause drywall 'blowouts' on the back side.

Install the Madison straps carefully and tightly as a final touch I use metal plates as they add a lot of support when people push the plugs in and have more depth to cover the box ears.

Pay attention to box fill, only one 12/2 cable per box.

Oh don't forget to cut the receptacle yoke to fit inside the box ears.
 
When using cut in boxes with madison straps is a 90 deg flex connector really inaccessible?

If any of theses walls are fire walls the madison straps are out of the question.

Roger
 
roger said:
When using cut in boxes with madison straps is a 90 deg flex connector really inaccessible?
Click to expand...

I guess that depends on if you consider the box part of the building finish.;)

Honestly no, not by a strict reading of the definition. :)

Just not a fan of 'rear entry'.

If any of theses walls are fire walls the Madison straps are out of the question.
Click to expand...

Good point.....one that is virtually unknown in my area.

Have a great forth of July Roger. :)
 
iwire said:
Have a great forth of July Roger. :)
Click to expand...

And you too Bob, and everyone else as well.
icon14.gif


Roger
 
Roger - what section of the code specfies you can't use teh madison straps? By the way, how did "madison straps" get their name? When working through my apprenticeship in NY, we always called them "holdzit" straps.

THanks,

Brett
 
bjp_ne_elec said:
what section of the code specifies you can't use teh madison straps?
Click to expand...

Not the NEC it is more of a UL rated firewall assembly building code issue.

But if it is a double layer firewall and you cut a big hole to mount your boxes patching without overlapping seems is a pain in the rear as well.
 
Was going to edit my previous post, but Iwire already responded.

I would imagine that if it's a fire wall, then it's probably loaded with insulation as well. That brings up another interesting challange - and let's here how some of you would handle that challange.

One of the things with this job, is that the business owner is green. First when he called, he said he needed an electrician to give him an estimate on a "100 A" service added in a commercial building. So I'm thinking - no ladder needed when I show up to find out he wants 110 volt receptacles added around the place - and find 14' ceilings. We also looked at the panels and I quizzed him about the amount of breakers in the panel. The panel only had 14 circuits labeled, but the panel was almost fully loaded with breakers. Do they typically run homeruns throughout the ceiling in spaces like this, anticapating the the tenant will need to tap in to them at various locations?

He's dealing with some leasing broker, but doesn't have direct contact with the buildings owners. I've asked him to get a set of prints and see what we can find out about if any circuits are already sprinkled about. I think he's already got another price or two - so I'm not sure how the other guys bid it. If there are HR's that are already run around to cover the 10 - 12 circuits I need to establish, this will save needing to get up above the ceiling and run EMT. This would obviously reduce the bid, and the business owner's expense of the overall job.

THanks

Brett
 
Last edited:
Brett, here is the UL info

WALL AND PARTITION ASSEMBLIES

Metallic Eletrical Outlet Boxes
Listed single and double gang metallic outlet and switch boxes with metallic or nonmetalliccover plates may be used in bearing and nonbearing wood stud and steel stud walls with ratings not exceeding 2h. These walls shall have gypsum wallboard facings similar to those shown in Design Nos. U301,U411, and U425. The metallic outlet or switch boxes shall be securely fastened to the studs and the opening in the wallboard facing shall be cut so that the clearance between the box and the wallboard does not exceed 1/8 in. The surface area of individual metallic outlet or switch boxes shall not exceed 16 sq in. The aggregate surface area of the boxes shall not exceed 100 sq in per 100 sq ft of wall surface.
Metallic boxes located on opposite sides of walls or partitions shall be seperated by a minimum horizontal distance of 24in. This minimum seperation distance between metallic boxes may be reduced when "Wall Opening Protective Materials" (CLIV) are installed according to the requirements of their Classification. Metallic boxes shall not be installed on opposite side of walls or partitions of staggered stud construction unless "Wall Opening Protective Materials" are installed according to the requirements of their Classification.
Click to expand...
the boxes must be fastened to the studs.

I don't know how all the names came about for Madison Straps, I have heard them called jiffy clips, steam ships, holdits, box holders and more.

Roger
 
macmikeman said:
Using a 90 deg flex connector inside a finished wall rings code alarm bells in my head, go read 350-20.
Click to expand...


Article 350 in the 1999 NEC is for FMC not MC cable. Besides why would a 90 degree connector on a piece of MC cable be a violation? MC is not a raceway. There is nothing wrong with a 90 degree connector on MC cable.
 
Sometimes, if I'm concerned about a old work box staying secure, I will run a bead of liquid nails around the outside of the box (near the edge) before I push it into the wall.
Just a thought
steve
 
I doubt that liquid nails would be a good idea in a fire wall since the glue is flammable. Around here they let you use a fire rated putty on metal boxes. They sell it in squares that are 1/4" thick and just right for a 1900 box at Graybar. Cost about $2.00 to fire proof a box. bjp_ne_elect I have one bit of advice. If this owner is green then asked to see the other bids ( not the price quoted just the scope of work ), this will let you know if the others are planning on charging for new circuits and how many. If there are spare circuit you may be able to cut their price and still make some good money on the job. If you take the time to do the research you should be paid for it.
 
Status
Not open for further replies.
Top