The demoman is one of the most versatile of classes in TF. He has the firepower to take on multiple enemies and come out on top and moves at a neat pace. This makes him an effective offensive unit for breaking strangleholds & devastating blitzes. His pipebombs and detpacks make him great for defense, holding bottlenecks & doorways. Below is a summary of tricks and tips for the demoman, first general tips and then specific tactics for the various roles the demoman finds himself in.

General tips

• Pipebombs are your best friend, I usually have them as my default weapon and when used properly will give you better results than grenade spamming. Make sure you have an accessible key bound to detonate your pipes (I use space bar). When you have an enemy at a medium distance you can throw pipes & detonate them when they get close to him. Few will get away unscathed.
• Another trick is to spam an area around an enemy quickly with pipes so that he has nowhere to dodge, this is best used in a confined space, if you die the pipes go off too.
• If you have laid a pipebomb trap, use normal grenades for general melee rather than waste your precious trap.
• Remember your jump key. If you are running forward & jump before you fire, your grenade will go a LOT further. This is especially cool for pipebombing people that are running away from you :).
• Be aware of your health and armor!. You aren’t a soldier anymore. Sure you can dish it out to soldiers but you cant take it anywhere near the way they can. If possible always try to strike obliquely and not head on. If people are gunning for you, switch to grenades run backwards & spam!. This usually gives you some breathing space.
• Mirv grenades Bwahahahahaha. If in enemy territory try not to die before dropping one of these suckers for a little payback (with luck). One of these babies will take down a sentry & that’s one of their best uses. Drop one in front of spawn rooms to cause trouble & the odd frag. If you are on defense & need to resupply, drop one or two to hold the fort while you are gone.
• You have to be tricky to use detpacks. Strangely killing people isn’t the best use for them. If you put them on ramps & in corridors so that people walk into them, the detpack will trip them up ie. they will be stuck for a moment. This is a perfect time to grenade them :).
• Detpacks are also used to open the passage in the rock maps & the grates in well6.
• Sometimes on the odd occasion it will pay to pull out the trusty shotgun for targets at a distance.
• Grenade jumps are pretty easy with pipebombs & they will get you pretty far, just remember to jump before you detonate. Two pipes will get you heaps further..just about anywhere actually but the damage to yourself is very high and usually not worth it.

Offense
Know where the sentry is & hunt it down, this is the best role for the offensive demoman. Sometimes the sentry will be in places that your grenades cant reach (e.g. On a high ledge) & if they have formed a bottleneck then you’re pretty much useless......time to be a soldier. Having an indirect weapon makes life tough sometimes but get you self in a corridor or ramp & you shine. As stated before Mirv those spawn points. If you are overwhelmed, let everything fly Mirvs & grenades :). When fighting soldiers, remember that they only have 4 shots so avoid them till then.

If you’ve got the flag, shoot grenades in front of yourself so that they detonate behind you, discouraging pursuit. When storming a base it is handy if you have a soldier or two to hide behind till you get into weapons range to save your precious armor.

Defense
The best use for a defensive demoman is to pipe an area & wait for foolish attackers. The best spots are behind doors, on ramps & around the flag. Be careful coz you’ll only surprise them once and then they’ll be gunning for you. Make sure you have your normal grenades ready & the clip is full. You can lay up to seven pipes on the ground & you will have to practice to get the right layout. Be aware that scouts will flash by in a blink & you’ll need some spread out pipes to catch them. If things are getting tough, use your Mirvs to hold them off, especially if you are guarding the flag.

Use detpacks to choke narrow ways.

If someone does get past you & it looks like they’ll get to the flag, don’t waste time chasing them if your not certain you’ll get them, lay pipes & catch them on the way out of the flag room. People get a lot less cautious when they’ve got the flag.

BE SNEAKY. Think ‘what will the enemy do now?’ & plan a trap for them.

Aliases and commands

Pipebomb jump:
alias pj "+jump; wait; detpipe; -jump"
bind X "pj"

Detpaks:
This will set a 5 second detpak: bind X "+det5"
This will set a 20 second detpak: bind X "+det20"
This will set a 50 second detpak: bind X "+det50"

Weapon aliases::
//This will fire a pipebomb and detonate it after launch:
bind X "impulse 7;+attack;wait;-attack;wait;detpipe"
//This will fire a pipebomb without having to switch weapon:
bind X " impulse 7;+attack;wait;-attack"
//This will fire a grenade without having to switch weapon:
bind X "impulse 6;+attack;wait;-attack"
This will fire the shotgun without having to switch weapon:
bind X "impulse 2;+attack;wait;-attack"

Class binds:
bind X "detpipe" This will detonate your pipebombs.
bind X "reload" This will reload your weapon.
bind X "id" This will enable you to detect spys.
bind X "saveme" This will yell for a medic or an engineer.
bind X "inv" This will tell your inventory of grenades.
bind X "discard" This will drop stuff you don't need.

Other resources:
+Det5
Demoman Domain
UKFN Tactics for Demos
TF Guide class strategy for Demos