By Bob Catanzarite
The Rough-In - Chapter 1
The rough-in stage involves a lot of work being done in what usually is a short span of time. In order to get everything done in this short time span means that you need to be prepared. You have to know what you want to get done and have the tools and materials on hand to get it done.
The timing for the rough-in is critical too. Ideally the rough-in should be done BEFORE the drywall goes up. And it SHOULD be done AFTER the electricians, plumbers and HVAC people have finished their rough-in. Working AFTER the electricians, plumbers and HVAC people have finished their rough-in will allow you to place your wiring such that you'll be keeping the minimum distance away from things like electrical wiring, etc. See the reference page for these minimum recommended distances. Remember that you can cross your structured wiring with the electrical wiring and have spacing less then the recommended minimum distance but you should do so at 90º.
The goal of the rough-in is to install all of your room outlet boxes and run the cabling from the outlet boxes back to where the CWP (Central Wiring Panel) is going to be located. You may want to actually install the CWP during the rough-in especially if you are going to flush mount your CWP. Having some form of a floorplan done showing the rough location of all the outlet boxes is a must. I'll refer you here to the floorplan that I used. You also need to have a good idea where all of the cable bundles are going to run and where they are going to be routed as they get back to the CWP.
You have an option here at the rough-in stage that I haven't mentioned yet. You can install the actual cabling or you can just install 'pull cords'. Both of these options have pro's and con's. Let me explain what pull cords are and how they work. You can install pull cords running through the walls instead of the actual cable bundles during the rough-in. Then later on, usually after your home is finished, you secure the cable bundles to one end of this pull cord and pull on the other end of the pull cord which in turn pulls the cable bundles through the walls. Pull cords are just run through the walls from the outlet box to the attic or basement or crawl space.
I have a separate page with more information on the use of pull cords.
I chose to install pull cords during my rough-in and I'll explain why I did that.
I told my home construction supervisor well ahead of time what I was going to do here. I also told him that I didn't want his people to staple down or otherwise disturb any of my cables. He was concerned that this could pose a problem during a pre-drywall inspection process that takes place just before the drywall goes up. Building inspectors do this pre-drywall inspection to make sure the construction, electrical, plumbing etc. was done to code before all that gets covered up by the drywall. Although the type of wiring involved in a structured wiring plan is usually not covered by local codes, these inspectors MAY see some kind of problem with the wiring that you installed. A builder doesn't want to have to deal with problems with things like this. This was one of the reasons I chose to install pull cords instead of cabling.
Another reason was the 18" of wire that I wanted to have coming out of the outlet boxes. Having this 18" of cable out of the box made sure I had enough cable to work on during the finishing stage. I was using single gang outlet boxes and had five cables running to each of the boxes. See the figure to the right. It was just not going to be possible to stuff this 18" bundle of five cables back into the small single gang outlet box so that the cable would not get in the way during the drywall installation and the other stages of finishing the home. Having this cable bundle hanging out of the outlet boxes left it vulnerable to being cut, mangled, pinched, painted and all sorts of nasty things. Pull cords can easily be stuffed into and better yet tied to the outlet boxes.
Another reason to install pull cords is the time element - it is quicker to install pull cables -vs- real cables. This can helpful if the builder is giving you very little time for you to do your rough-in. Not having all your cabling on hand is another reason. Not having a well thought out floorplan ready is another. Not having a good idea where the CWP will be located is another.
The cons of pull cords are numerous as well. Pull cords can break when you are using them to pull cable bundles through the walls. Bad news - very frustrating and difficult to fix. Pull cables don't work well unless your pulling cable with them is a straight line. Don't plan on using these to pull cable bundles around corners. Cable bundles are thick and stiff. Even small jogs in the path can cause the cable bundle to bind and get hung up. If this binding or hanging up does occur you'll have a hard time fixing it because at this point your home will likely be finished already. It adds one more step to the whole install process - having to use the cords to pull the cable bundles through. One thing to remember if you choose to install pull cords - cable bundle that you will be pulling later on with these pull cords are MUCH thicker than the pull cords. When you are drilling holes for these pull cords make them large enough for the cable bundles. Run the pull cords in straight lines. Use pull cord that is strong enough so as not to break when your pulling cable bundles. Beware of potential places for things to get bound or hung up when pulling cable bundles later on.
This issue of installing pull cords -vs- cables will have to be your own decision.
Now on to installing the outlet boxes. For my project I chose to use the outlet boxes that are commonly used for electrical wiring that you can buy cheap at any hardware store. These type of boxes work well with one exception. The knock-out tabs that they have for the wiring to get in and out of are far too small for the bundle of cables that you'll have with a typical structured wiring system. To get around this problem I pre-drilled a larger holes in the top of all my boxes. See the photo below on the right. I used the same 1 1/8" spade (or auger) drill bit that I using to drill holes in the wall studs. Now you may need to drill your holes on the bottom or the back of the outlet box depending on how the cables will run out of the box.
You may have to make slight modification to the location for the outlet boxes called out on your floorplan in order to avoid things like electrical wiring, plumbing and other such things. Before you install an outlet box make sure there is a clear place for the cable bundles to run. Don't mount the outlet box's face flush with the stud you are nailing it to. The box's front surface needs to extend out from the stud far enough so that the box fits inside of the hole in the drywall the drywallers will be cutting later on. But you don't want the box's face to set out so far from the stud that the box face actually extends past the front surface of the drywall when it's hung up. See the photos below.
The photo on the left shows how how the outlet box should set inside the hole that will later be cut into the drywall. The photo on the right shows two ridges that came molded into the boxes that I used. The ridges are on the right side of the box. They are there to act as a guide to help you space the box face off the stud the proper distance. To set the height of the box from the floor I just set it to the same distance that the electricians used. This way the structured wiring outlet plates will end up the same height as the electrical outlets. While we are on the subject of matching the electrician - find out what color the electrician will be using for the electrical outlet covers and buy the same color for your structured wiring outlet covers. A better idea here would be to TELL the electricians what color you want them to use. Not all builders will ask you what color to use for the electrical trim. You can tell them what you want though.