Tricks of the Trade: How to Run Cable Behind Baseboards and Casings

One of the most frustrating things about fishing wire through the walls of older homes is encountering unexpected obstructions. Older homes often have one or more 2 X 4's running horizontally between studs as fire stops. Running wire through such a wall space is very time consuming and labor intensive. First, you have to locate each of those horizontal blocks.

Next you have to remove a section of the wall finish in front of each of those blocks, large enough to allow you to drill through the block or to notch the block for the cable to pass through it. Then, after getting the cable where you need it, you have to go back and patch all the holes you made in the wall. Having to patch a hole/cutout in a modern wall with a wallboard finish may not be all that bad, but you have quite a job on your hands if you are working on an older home that has plaster wall laid over wooden lath. Running the wire behind baseboards and around door casing takes a fraction of the time while causing little damage to the wall finish.

Tools and supplies needed for this project

• Carpenter's Claw Hammer

• 5 in 1 Tool

• Flat Pry Bar/Stanley Bar

• Utility Knife

• 4” Putty Knife

• Nail Set

• Scrap Piece of Plywood

• 3/8-Inch Drill/Driver

• Portable Electric Jigsaw

• 1-Inch Wood Chisel

• 24-Inch Carpenter's Level

• Tape Measure

• Carpenter's Pencil or Felt Tip Marker

• Nailing Plates

Removing the Baseboard

Proceed carefully here, especially when working on older homes, because wood dries out with time and it is very easy to crack a baseboard or door casing during removal. Finding an exact replacement molding may be impossible and will end up a custom molding milled to order and that can get expensive. If you follow these steps and work slowly, you should not have any problems.

Using your utility knife, carefully cut the caulking and/or paint bead between the top of the baseboard and the wall. If you neglect to cut through the bead first, you damage the wall when prying off the baseboard. With wallboard, the paper facing is easily ripped if the bead is not broken. With older, plastered walls, large chunks of the plaster is likely to come off with the baseboard if you skip this step.

Once you have cut through the bead, carefully drive the 5-in-1 tool down behind the baseboard.

Your objective here is to create enough space between the baseboard and the wall to insert your Stanley Bar.

Place the plywood scrap between the Stanley Bar and the wall to keep from damaging the wall as you pry the baseboard away from it. Work you way slowly along the length of the baseboard, prying it away from the wall a little at a time. Trying to pry too much at one time will end up with you breaking the baseboard. Follow these same steps when removing a door casing.

Once you have removed the baseboard, cut a channel in the wall finish. Since “Nailing Plates” are 1 and ½ inches by 5 inches, you need to cut a channel in the wall behind the baseboard at least 5 inches in width.

Outline the area to be cutout using your level and felt tip marker. Then drill 3/8-inch holes in each corner of the cutout so you can insert the blade of your portable electric jig saw.

Set the depth of cut for 1 and ½ inches so you will cut through the wall finish but not the wall studs at the same time. Once you have made the channel, cut a 3-inch long X 1-inch  deep notch in the studs using the jigsaw and the 1-inch wood chisel and hammer.

Once you have the cable in place, cover the notches with the steel nailing plates.

Running cable around doors behind the door casing

Once you have removed the door casing there will be a space already available for you to lay the cable in.

Reinstalling the baseboard

When reinstalling the baseboard, you will need to shim it out at the studs using wood the same thickness as the wall finish, which is usually 1/2-inch if you have wallboard. It is also a good idea to run a strip along the front of the wall's sill plate too for extra support.