DIY wiring your building

At some point I felt like DIY wiring a sort of community centre. Because of a lack of knowledge, I made mistakes, costing work, frustration, and some money. And hunting down all the knowledge cost a lot of time. Therefore, here is my write-up of everything I learned along the way.

Wiring your building is a big job, so you preferably only do it once, and then enjoy for a long time. Therefore, my recommendation is to not take any shortcuts, and to not skimp on costs. Because shortcuts will cause (often hard to detect) errors, which cause work, frustration, and ultimately having to re-do the wiring, meaning make costs instead of less.

The most often made error is to think wiring a bigger building is just like wiring your home: router > some cheap 8 port switch > some computers, printer, wifi etc. Just add some more cable and some more switches, right? No. Just like it's not recommended to plug 4 powerstrips into one powerstrip, and then 4 devices in each of those powerstrips: do NOT use multiple switches. Use as little switches as possible, which often will mean only one switch in one building. Even when this means pulling hundreds of meters of extra cable. Why, you ask? The answer is: switches introduce complexity, latency and use power 24/7. In this scenario, you end up with 2, 3 or more (probably low-performance) switches in between a device and the router. Don't do it! It will cause errors under load, often hard to pin down, as your switches have no or very limited diagnostics. Which causes frustration, and ultimately, a re-do. Meaning way more effort spent, and more money. (Yes, installations in big buildings or datacenters have multiple switches in a row. They are not DIY and cost €€€€. And there are still kilometers of cable in that building).

Less switches means more cable. Lets say you have a room where you need 4 connections, which is 10m from the switch. Just pull 40m of cable. It's a one time expense, but its worth it. Just buy as much cable as you need according to the plan, plus some extra.

Buy the right cable: solid core, 100% copper. Solid cable is made for permanent installation. It has better performace, especially over longer runs. It will break more easily when stressed, but since there will be no stress after installation, this is no issue. Copper is best for conductivity. There is a cheaper alternative called CCA. But you are risking performance issues, if not now, maybe in the future if you try to upgrade your devices to a higher speed. Copper does not have this risk.

Solid cable does not work with the familiar rj-45 plugs you crimp onto cable with pliers. There are plugs sold for solid cable. You may get lucky with a small installation. With a bigger installation, you will run into plugs not making connections on all the wires. If you absolutely have to try, buy plugs that are exactly made for exactly your wire. Even if the AWG of the wire and the plug match, still ask the shop first. If they don't know what your are talking about and recommend just some generic plug, don't do it. Even better, don't do it at all.

Solid cable is terminated onto a patch panel at the side of the switch, where all cables come together. On the side of the endpoints, it is terminated onto a wall outlet. From the patchpanel to the switch, and from the wall outlet to the device, you use a ready-made patchcable. This is the way to go, and it saves you from having to crimp any plugs onto cables, and leaves you with reliable connections. Termination is done with keystones, or on LSA strips with a punchdown tool. Keystones are more convenient, but more expensive.

Run cables in pipes or cable trays to protect the cable and have a neat installation. Plastic pipe is very cheap. Mount them first, then pull the cable trough. If you pull multiple parallel cables, make sure they don't tangle. At the point of the tangle the cables are thicker, making them harded to pull through, stressing the cable. This can be prevented by having a second person on the other end of the pipe. Or (my preferred method) by making a smooth bundle of cables without tangles, with some black installers' tape every 30cm. UTP cable is low voltage. Therefore, pipes or trays are just practical, not for isolation. So save yourself a lot of trouble, and only use pipe or tray for straight parts. In bends and corners, its fine to just have bare cables.

Solid cable comes rolled up in a box, or on a spool. Do not pull the cable of the side of the spool or roll! This will cause the cable to coil. If try to pull coiled cable into a pipe, it causes torsion on the cable, causing one or more wires to break. Instead, you need to place the coil or spool on some kind of axle so it can 'roll' freely when pulling of cable. One exception is a system called Reelex, which boxes cable in a way that prevents coiling. Leave cable in the box or on the spool for as long as possible. Big lenghts of cable laying on the floor will tangle.

Don't buy your cable in one length. For instance, lets say you need 1000m of cable. Buy 3 boxes of 300m and one of 100m, instead of one 1000m spool. Reason: this lets you pull multiple cables in parallel, straight from the box. With just one box, you need to pull out all the lengths of cable first, causing tangle, or you need to pull the cables one by one, meaning extra work.

CAT5, 6, 7, 8: at the time of writing CAT6 is the way to go, and it will be for a long time. It is marginally more expensive than CAT5e, but offers better performance, up to 10Gbit/s at max 55m lengths. That is, if your equipment supports it. CAT6a and up are more expensive, and have very tight tolerances. Make one mistake, and you lose all the benefits, and hunting down mistakes is hard. If you really need such performace, look at optical fibre instead. Make sure that when you choose CATx, all your components are CATx: cable, keystones, patchpanels etc.

FTP, SFTP: If you need this, you know. For instance because you run heavy machines that have already caused trouble with other electrical equipment. When in doubt, don't do it, also not 'just in case'. Save money and added complexity, go for UTP. Also, FTP and STP need to be terminated exactly right. If they are not, they can actually degrade the signal instead of improving it.

WiFi: one way to save on cable in a proper way is by having proper WiFi, which now is a great time to install, and then switching equipment currently using a cable, to WiFi. Most things people do on computers are fine with WiFi, and modern WiFi (AC/5 or up) is very reliable. There are limits of course, so the number of machines and workload should be matched to the power and number of the accesspoints. And there are some workloads that really still do require cable.

Power over Ethernet: some WiFi accesspoints, and other devices, can use Power over Ethernet. The benefit is, you dont have to place your accespoints near a power outlet, and you can have more things centralized in your equipment closet, in this case the power supply of these devices. Ideally, the switch you get has PoE integrated. Another benefit, is that you can power off devices remotely, for instances to save money on electricity during the night. Or for troubleshooting, meaning you don't have to get up on a ladder to get to your accesspoint. You can also power non-PoE devices with a PoE splitter, but do make sure its stable first. PoE is not the same as having a regular AC/DC adapter.

Connecting multiple buildings in one network: use fibre optic cable. It is a bit harder to work with, but not that expensive, and neither are (second-hand) switches supporting it. The reason is twofold: first, metal wire can can conduct a lightning strike into your building and equipment. Second, you are making an electric connection between to separate electric installations. This can cause electricity to be transported over your wire and equipment, causing issues.

Switch: start out with any second hand business-grade switch you want that has enough ports. Just watch the power usage, as its on 24/7. The big benefit of doing this project in the way described above, is that all active components (the one switch, and other appliances like servers, routers or power over ethernet adapters) can now be all in one closet. So the 'active' components of your installation are easily replacable when necessary. Also, when using a business-grade switch, you get more diagnostics, making problems much easier to trace.

Now that you've read all this, its time to get going. First of all, make a floorplan. Decide the best location for your switch. This will be a central location, ideally in some kind of closet where it can make a bit of noise (fans). Draw the locations of the wall outlets. Then calculate the lengths of wiring and the number of outlets. Add some slack on both sides. What will you need to buy in the very least:

  • cable
  • patchpanel. Get a 19" one if your switch will also be 19". Make sure it has enough ports, with some room for future expansion.
  • wall outlets
  • keystones, if you will use them
  • LSA punchdown tool, if you use LSA strips
  • Cable stripper tool. The ones on plug crimper suck. Buy a nice one, like the barrel shaped models, as you will be stripping a lot of cable. Make sure to check it strips UTP sized cable and not just the thicker 240v cable.
  • installers tape (black, somewhat rubber-like/flexible)
  • zipties to for the patch panel and organizing the wiring closet
  • switch. Make sure it has enough ports, with some room for future expansion. With Power over Ethernet for WiFi accespoints, make sure the power budget of the switch is enough, and the PoE type matches the one required by the accespoints.
  • cable tester: tells you if one of the wire's isn't connected.

Second hand:

  • A switch, the tools and the tester you can get secondhand. Factory-reset the switch. Test if all ports on the switch work with your laptop.
  • With patchpanels, keystones and wall outlets, make sure the connecting points for the wires aren't damaged (they can break if cable is ripped out).
  • Getting cable secondhand is a risk. If you have pulled 50m of cable trough 6 different rooms and it turns out there is a break, you will curse yourself. Also, if its not boxed or spooled up anymore, it adds hassle. So make sure the money you save is worth the extra time and effort you will spend. If cable is one big length (preferred), test it with a cable tester. Make sure the specifications printed on the side of the cable are the ones you want. For smaller lengths its too much effort to test them. You should get these for close to free, as very few people will buy this.

Good luck! (which you will need much less of if you follow the above)