Prefab

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dcv

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texas
My company is wanting to me get into prefabricating
as much as I can in the on going job I am currently working on.
The product will consist of this: 1-25'HCF cable connected to 1- 1900 box with a mounting bracket(caddy),a 3/4" mud ring and a receptacle with tape as protection from paint and sheetrock mud,(all of this will be done 150 times) now the parts I listed will be mostly typical on this project and are subject to change according to the need of the application.
This product will be used in patient rooms (normal power only)and any other areas where a typical product like this can be applied.
I am unsure of the cost saving and I am interested in what some of you that have done this before have to say.
I would like to here some pro's and con's on this subject.
All opinions will be appreciated
dcv :roll:
 
Re: Prefab

Why the rolling eyes? You have the option to make up everything you need in a clean, heated, well lit shop with a bathroom nearby (assuming your company has a shop with those amenities). Sounds like a no brainer.
 
Re: Prefab

Maybe, I was not to clear in my first post ,I personally will not be the one doing the work, the point I was asking is if the prefabrication method would be cost effective.
dcv
 
Re: Prefab

i did a 34 story condo building and we used to prefabricate everything we could think of. it is cost effective and we used people who we handicapped to do the prefab. the prefab would be bundled up "per floor" amounts and landed as soon as the floor was poured. we rigged a cart with a port-a-band saw to cut all the floor stubs off at the same heighth. say six inches above finished floor. we would ream the stub and install taped close couplings on the stub. this made it safer and also reduced the number of bent over pipes since they were short. ten inch nipples with box offsets were prefabbed to use in the rough. the nipple's legnth provided proper box heighth and the offsets allowed for movement to roll the box to the surface of the partition. one man would do the boxing and rough in. we put as much as the pipework in the slab as we could. panels were prefabbed by using templetes during the slab that matched the knockout pattern of the panelboard. again the pipes for the panelboard installation were prefabbed with offsets and cut the same, at proper lengths to install the panelboard without cutting a pipe. probibly, the biggest advantage was the team work that this type of operation creates on a job and also in the prefab shop.
 
Re: Prefab

I guess your inspectors will let you install devices before the rough in inspection. Why not do the switches and even the lay in lights. Come on this is a health care facility and no matter what the engineers say about every head wall being the same, it ain't that way in the real world. To many med gas, vacum lines, nurse call and on and on. Then you have to figure out how to put in the electric stuff. If this is a patient room as you say one duplex on normal power may meet code but will it meet jobs specs. If you tried to this in my hospital you would be out the door before you could get your rope in the wall.
 
Re: Prefab

dcv,
Pre-fab is the way to go,the more mirror footprints on the plans the better it pays.
Even pre-fabbing on the site will be better,faster,and more savings than regular methods.
frank
 
Re: Prefab

Frank, out of curiosity, have you ever done any "Equipotential" ground testing in a "Patient Care Area" to meet the criteria of 4.3.3 of NFPA 99?

There are some issues with loose connections that may be a problem with trying to meet the less than .1 ohm requirement if these prefab units are moved around to much during installation.

This less than .1 ohm measurement must be made with recognized Bio Med equipment, which is calibrated yearly.

Dcv, is asking this question for opinions only, he is well knowledged in hospital installations.

Roger
 
Re: Prefab

Originally posted by roger:

There are some issues with loose connections that may be a problem with trying to meet the less than .1 ohm requirement if these prefab units are moved around to much during installation.

Roger
Click to expand...
So prefabbing anything going into a hospital is not such a good idea?
 
Re: Prefab

if i needed 400 -- 4 11/16" one piece steel boxes with two one inch steel connectors -straight through and a 3/4" steel connector out the right side with a number 12 equipment bond wire in it. i could have them prefabbed either on site or off site and it really shouldn't effect the ground spec you mentioned??? hospital-office tower-residential....
 
Re: Prefab

Frank, look at the OP and notice the term HCF and Patient rooms, this should be a clue as to where my post came from as well as Jeff's reply.

Charlie, let me assure you that getting all devices in a patient care area to be within this limit is not always a given when it comes to commissioning a room, even without this type of handling.

Roger

[ March 01, 2005, 09:16 PM: Message edited by: roger ]
 
Re: Prefab

roger,
Look at OP yourself,take out the words "patient room" and term HFC and answer the question!
Notice this,the 3rd post by the OP'er clarifies what his intent is,"PRE-FAB". Did you miss the part in OP that states "any other area where a typical product like this can be applied".
Lastly, do you like the way you post answers used against yourself?
frank
 
Re: Prefab

Originally posted by benaround:
roger,
Look at OP yourself,take out the words "patient room" and term HFC and answer the question!
Notice this,the 3rd post by the OP'er clarifies what his intent is,"PRE-FAB". Did you miss the part in OP that states "any other area where a typical product like this can be applied".
frank
Click to expand...
Frank, what are you talking about? There is no 3rd post by DCV in this thread.

Then
Lastly, do you like the way you post answers used against yourself?
Click to expand...
I must ask again, what are you talking about? :D

Roger
 
Re: Prefab

dcv
How are the ears of the recept. going to be against the sheetrock if you install them for the wall is rocked?
Rockers love their zip routers.I bet the device will not survive. I am all for prefab but don't go to far.
 
Re: Prefab

I work for the same company as dcv and have talked to him about this issue. His original post is asking about a specific application, a 25' piece of HCF connected to a box with a recept installed.

My thoughts were pretty much all negative. What kind of time is being saved here?

A man will have to measure each length of HCF, roll it up and secure it. Distribute them throughout the job. The HCF will now have to be unrolled. The box will have to be mounted with 25' of HCF coming out the top. A man will still have to secure the cable from the recept to the j-box above ceiling. The HCF would already have a connector on it, so more than likely it would not be tightened sufficiently at the j-box. All the handling would probably loosen the connector at the receptacle. What to do with any slack in the cable. What to do when the cable is too short. What to do when the tabs on the recept are pinned behind the sheetrock. .....

On the positive side. The HCF will already be stripped out on both ends, and the pre-fab man will have a restroom close by. :)

Bottom line is, I think a man with a roll of HCF will be faster and the quality of work will be better.

I would also like to here others opinions, although "upper management" might not.

Brent
 
Re: Prefab

In my first post I asked but was never answered about your inspectors letting you install devices before rough-in inspection, does that happen? As far as taking out stuff from the OP if you want to put conectors in boxes great go for it. But to make up and assembly like this to put in a patient care facility, I just don't see it happening. Where are you guys that want to save resources at on this post? 25 feet of AC cable man that could be way to long or way to short.
 
Re: Prefab

caj1962

Read my post again brother. It's right above your post.

This is something that might be crammed down our throats. If I can talk for dcv, neither one of us are comfortable with it. The original post was asking for pros vs cons. Your comment about inspections has been well received.

This is not our companies first health care facility. We have done many. This is something new being kicked around by management in order to be more efficient and competetive. At the same time we do not want to sacrifice quality. That leads to the question, can it be done?

[ March 02, 2005, 06:37 PM: Message edited by: brentp ]
 
Re: Prefab

I think Brent is correct on this issue, where is the savings here? I'm sure the process of making these items will be quick,but if 1 tail is 1 foot too long this mean 50 tails are too long,that's 50' of HCF cable wasted .That coupled with handling these items "8" times,..yes! 8 times...far out weighs any saving we may have incurred in doing this.
Jeff mention, inspections,this I believe could easily turn into a costly problem if any rework is required.
Ears on the receptacles will not be on the surface of the sheetrock another good point, although 3/4" mud ring works perfect with 5/8" so the device will be flush with the rock surface,which should relieve any type of support needed from the sheetrock .
Roger, brought up Equipotential grounding,"thank you Roger" if anything will shoot this idea down this reason will ,I do this test myself and I am not looking forward to tightening screws at the last minute to pass TDH's inspection.
This is a part of quality control which is on going everyday from outlet to outlet not,every 50 outlets to 50 outlets.
thanks to all
 
Re: Prefab

Brentp I agree with you when prefabs are done there are all to many variables to consider.If this is a cookie cutter enviorment then by all means go for it.But in a hosptal for example there are all to many different types of rooms with all to many different types of equiptment :D
 
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