Wiring – Cabling into concrete

I was afraid of doing this the first time; but after a plumber let me assist him I saw it was pretty basic. When you want to clear a drain pipe you want to consider the diameter of the pipe and the material of the pipe. The size of the pipe will determine what size bits you want to use. Bits come in a variety of sizes and shapes to handle different size pipes and types of blockage. Since you are overflowing at the toilet seal, I'm going to assume you want to clear your main line which is going to be pretty big.

The size of the bit will also determine the thickness of the cable you need to use. If you use a cable that's too thin for the bit, it will bind up and could become a twisted mess when it hits the blockage. For most jobs, the power drain cleaner you can rent at Home Depot is sufficient.

An important point is to go slow and use a low speed until you get to the blockage. The thing you want to avoid is to have the bit banging around with so much force that you damage the pipe, especially if you have a brittle material like clay. Start with a small bit to see how far the blockage is and how tough it is. Work the small bit through the blockage if you can, and then replace the bit with a larger one and repeat until you have the pipe cleared.

The 'tricky' part is working through the blockage without twisting the cable. You don't want to push the cable, just let it pull itself through the pipe and blockage. You also want to make sure to wear a pair of thick leather gloves. If the cable does twist up it will protect your hands and fingers from getting seriously pinched.

If you think there is some kind of damage or other serious issue, you can rent a camera to inspect the inside of the drain pipe. Most of them will also give you a distance measurement and record the video. This would be useful if you have to bring in a professional plumber.

Concrete walls typically have conduits where all wiring passes (edit: as pointed out by @alx9r, this might not always be the case. Sometimes wiring is cast directly into the concrete). This allows you to add additional wires to the same conduits, but doesn't help if you need to pass a wire between two places that don't have a conduit already in the wall.

Whether or not you can use the existing conduits is both a matter of convenience (are there existing conduits from and to the place you want to run the Ethernet cabling) and of wiring code - is it allowed to run Ethernet (low voltage) cabling along side other cables - high voltage (110/220 V), phone lines, TV coaxial cables, etc.

If there are no existing conduits you can use, you'd need to consider several options (all pictures from Google Images):

1. Run the cable along the walls, often by the skirting boards. The cable can be attached with clips to the wall. This method is easiest, cheapest and fastest, but people often don't like cables running visibly around the house and if the cables aren't properly secured they might be a tripping hazard.

   

2. Run the cables in plastic channels that are attached to the walls. This is similar to number 1, only that the channels help hold the cable better and are probably more aesthetic.

   

3. Run new conduits in the wall. This is done by carving a channel in the wall (called "wall chasing"), placing a plastic conduit in the channel, mortaring the conduit in place and patching up the channel on top of the conduit. As can be imagined, this is hard work (especially for long distances), very dirty (especially if grinding disc cutters are used to score the channel) and must be done carefully to avoid hitting other cables and pipes already in the wall. However, this will give the best aesthetic result.

   

If a conduit is used, fishing the new cable through the conduit is done either using preexisting cables in the conduit or with a fish tape. The new cable is attached to the preexisting cable or the fist tape (after pushing the fish tape through the conduit to the other side) and then pulled until the new cable is fully in the conduit. From my experience, if you have cables already in the conduit, it is much easier to pull them completely out and then fish the entire bundle (old cable/cables together with new Ethernet cable) back into the conduit.

Finally, Cat6 doesn't give that much of a difference in the common house over Cat5e - the extra shielding is useful with lots of cables running close together and for long distances. For home use spans are usually much shorter than the maximum 100 meters defined for Ethernet and there are only a few cables running side by side. However, Cat6 is much stiffer than Cat5e, making it quite challenging to fish it through conduits.