Wallfishing cable- An introduction
Wallfishing cable is one of the most dreaded tasks a CableTech can perform. ( It falls right ABOVE running a new mid-span or sub pole to pole drop..) but it shouldnt be.
There are various reasons why Wallfishing cable is such a mystery. Ill list a few here-
- 1-Techs arent carpenters. They arent trained as carpenters. They generally take a quick modual based course on home construction and are exposed to a few in classroom props to practice on. The few wallfishes you perform, the less experience you will have.
- 2- What is in that wall? Insulation, exposed wiring, water lines, horizontal fire stops?
- 3- Liability. Be you a contractor or inhouse tech there will always be some reprocussions for a foot through a ceiling, a drill through a water line or, knock on wood, a metal drill bit through a power line.
- 4- Time. If you are going to do a “custom job” which wall fishes are considered these days, you want to take your time to avoid everything previously mentioned. In the present days of efficiency and 2 hour timeframes, this becomes a balancing act.
We will skip some knowns. Lets assume you know where the cable is coming from and you have laid out the best place to drop the outlet.
Good things to avoid?
Exterior walls – They generally have insulation in them and various other obstacles which make wallfishing cable tricky.
Wet walls- Wet walls are any wall that houses your main water lines. Kitchens, bathrooms etc. These are generally loaded with piping. If you KNOW what you are doing these walls can be useful and you can see from below where the line goes up and can judge for accuracy a little better. But this all comes with time.
Most cable lines come into the basement. So we can start there and cover most scenarios. This can entail a very short wallfish from the basement to the next floor up or a longer wallfish from the basement to the attic. ( yes. it can be done )
If I am Wallfishing from a basement to an attic the first thing I look for is the “stink stack” or Vent Pipe for the home waste plumbing system. This is generally a larger black pipe ( or white PVC these days ) that runs from the basement all the way to the attic and out the attic to a vent. It is used to vent dangerous gases to the exterior of the home. Why is this a good bet?
Its a straight shot to the attic.
Also some homes have vents for other uses as well that might go from the basement to the attic as opposed to the side of the home. Look at the roof for tell tail signs of these golden pathways. Rain caps.
Most Vent Pipes have enough room on either side of them to allow for a fiberglass rod to slide up or down for your wallfish. Ive even had a few that allowed me enough space to simply weight my RG6 cable with an old triple trap and lower it right down to the basement. ( older homes)
For this fish you will typically use fiberglass rods or gravity. Fiberglass rods are usually provided by your employer but you can also get them at most Big Box Home Improvement stores. These are generally called GLOW STICKS as they are meant to be seen inside walls. They come with an array of “ends” as well for either attaching or retrieving cable or clearing an impass.
Another way to fish from an attic to a basement where the home run may start it by using common closets. Generally easier as long as each floor shares a similar floor plan. You can sometimes drill a hole in the far upper corner of a bedroom closet and pull a line down from the attic and then drill a hole in the same corner /floor of the closet and pass the line down to the next closet. Do this until you reach the basement.
Its also a good idea to use this method to put an outlet in a room. Its a cheap wallfish that just allows a hole in the corner of the inside closet ceiling and allows you to route your cable within the closet to either that room or an adjoining room on the other side of the closet wall. Pop a wallplate on the wall and you are good to go.
One of our premier members “Wallfishman” also offered some quality advice.
I go down the basement and try to fish up. i use greenlee fishsticks. whatever sticks you use you need to figure the length of them into what you are fishing.
Example if I’m going from basement to attic in a normal house i know that my sticks are 5 ft long, and i know by my walkthrough how many floors and how high they are. walls are normally 8 ft so 2 of those + 1ft thick floor between first and second floor = 8 x 2 + 1 = 17 . So I know that if i get 4 fishsticks up next to that pipe I’m in the attic.
When you goto the basement and find the sewer stack if you see phone or electric or alarm lines already going up next to those pipes thats a good sign. especially if you look in the attic and see those same lines coming out next to the sewer pipe. that means its been done before and can likely be done again.
The problem with sewer stacks is that many of them turn between the first and second floor. Again you will know by only 2 sticks going up there. Your beat if that happens and you move on. Sometimes i just walk around the basement while i have my sticks right there and just try sending them up next to things. in a split level you can fish next to the chimney to get to the attic.
In alot of real old stone houses the exterior walls are all on ferring strips. so theres a 3/4 inch space basically around the whole exterior of the house. sometimes you can go right up that space from basement to attic that way, but sometimes you will hit at the second floor.
In the mansions you can also use return air vents .
The stairway walls are usually the good ones. especially the double vents that take up 2 bays. 2 HBO filters and try dropping it sometimes you have to try for 5 minutes before it falls down past the second floor. if you do make it to the basement you now have a line hanging out of the vent 6 ft high on the second floor. if they want alot upstairs i use that line to pull 3-4 more whatever. then i take the right angle drill stick it in the vent and drill up into the attic. I drill like a 1 inch hole with those spade bits. Then shove the lines up into the attic . From there we can put anywhere on second floor you want. If the customer dont care i steer them towards interior / hollow walls. When we are walking around together, i throw wallplates on the floor in front of where they want them so i dont forget.
Look out for posts on tools, further tricks, MDU in unit fishes and other techniques!
If you have any comments you can leave them here or, encouraged, in the Installation Forum.