Maybe my search-fu is getting rusty, but I couldn't find a good explanation for how fire spreads. The few I found were guesswork or obviously wrong. It surprised me that the details weren't on the wiki either. I therefore present the result of my own research.
Warning: Back up your world before trying! I have had complete success with the following methods, but you never know...
Fire
Don't think of blocks as being on fire or not. The important thing to remember is that fire is a block that can only live next to combustible materials. When a block of fire exists, it may spread to any other available block (i.e. a block of air) inside a volume of 3x3x6 meters. There is no checking for available paths, so you can not stop fire from spreading by placing stone blocks in between.
This is where fire may spread, as seen from the side:
[] [] []
[] [] []
[] [] []
[] [] []
[] []
[] [] []
Remember that the fire shown doesn't have to be on the top of a block. It can also be on the side of a block. In the following example, the side of a wooden block is on fire, and all the logs are in danger of catching fire.
Only one of these logs is inside the zone where fire may spread, but the other logs enable the fire to spread to the block on one of their sides.
How to shrink the fire zone
Since fire can only spread to (and replace) blocks of air, you can replace air-blocks with something else to prevent spread. In the example above, logs 5 meters above the fire are in danger, because the blocks underneath are available. By placing the logs one step lower, and filling in the fire zone underneath with something non-flammable, you can save one meter.
Personally, I prefer not putting a wooden floor above the fire. You wouldn't do it in real life either. Build a chimney instead; it looks better.
When creating a fireplace, you usually place your fire on top of a block of netherrack. To prevent the floor from catching fire, simply block off the sides of the netherrack:
[] [] [] []
Remember that fire can spread indirectly. If you place the block of netherrack one level above the floor, the side of it can catch fire, thus allowing the fire to spread one extra block. In other words, don't do this:
[] [] [] []
[] [] [] []
Edit: Actually, this is probably only true if you are burning something other than netherrack. The sides of netherrack can not be set on fire, and fire never spreads to netherrack. [Thanks to Celaeris for the info]
Remember that half-plates occupy the entire block too. If you want a raised fire, you can surround the netherrack with half-plates just as well as any other non-combustible materials.
Making it even smaller (for permanent fires only)
I don't have a single player world to test this in, so I can only vouch for it in multiplayer. Also, it is dangerous. If you light the fire with nothing combustible touching the fire zone, the game seems to forget that the fire can spread. Maybe it is some kind of optimisation. Therefore, you can simply build your wooden structure after lighting the fire.
Edit: The reason is that fire stops updating after 15 ticks. [Thanks to Celaeris for the info]
I don't recommend this, though. You may be fine with it in single player mode, but in multiplayer, some sod will be sure to come along and put the fire out by accident. Shortly afterwards, he will watch in astonishment at what happens when he tries to re-ignite it.
Another possible problem is that the game may re-check the fire zone based on other triggers. Some forum threads suggest that walking into the fire will cause such a zone check. I wouldn't be surprised if throwing something into the fire did the same.
I will update this post if I find out something more about exactly how this works.
In my first wooden house, I was like "Fire is dangerous, but I'll build a good fireplace for safety." Then my whole house burned down. So I rebuild it, with a larger fireplace. It did burn again. So I rebuilt it without the fireplace.
I just build a new wooden house. I'll be experimenting soon… Wish me good luck!
“Two things are infinite: the universe and human stupidity; and I'm not sure about the universe.” — Albert Einstein
"Never try to teach a pig to sing; it wastes your time and it annoys the pig." — Robert Heinlein
My fire zone illustration in that thread was larger but that was because my focus was on where a flammable block was at risk and not the blocks of air that a fire could actually occupy. Your explanation is better in that regard.
I never did get around to studying lava as you seem to be. I assumed the fire mechanic may be centered on the lava itself, but never got around to actually testing it. I look forward to your findings.
Thanks for your responses, people. I'm glad you found it useful.
Quote from WiseGuy57 »
Here is my guide to not burning down your house:
Don't build houses out of wood. If you think cobblestone is so disgusting, just change it with a texture pack.
That is a possibility, but methinks you shouldn't limit yourself like that. Look at the real world. Some buildings are made of wood. I wouldn't want to limit the diversity in my buildings by not using wood.
Quote from Radioaktiivinen »
Waht the zone looks from above?
[snip]
?????
That one. It's a 3x3x6 box.
Quote from rodabon »
Thanks for revisiting this. I found your post and explanation about fire and the fire zone very well illustrated.
My fire zone illustration in that thread was larger but that was because my focus was on where a flammable block was at risk and not the blocks of air that a fire could actually occupy. Your explanation is better in that regard.
I never did get around to studying lava as you seem to be. I assumed the fire mechanic may be centered on the lava itself, but never got around to actually testing it. I look forward to your findings.
Ah, that would have saved me some time. It seems we pretty much reached the same conclusion.
Quote from Bousky »
In my first wooden house, I was like "Fire is dangerous, but I'll build a good fireplace for safety." Then my whole house burned down. So I rebuild it, with a larger fireplace. It did burn again. So I rebuilt it without the fireplace.
Make your home out of Stone, cobblestone, or bricks.... Problem solved.
Rollback Post to RevisionRollBack
If I for some reason offended you...
"I'm sorry you're just a little ****-ant who can't hold his liquids out in public. Now stop that cryin' 'fore I throw you out that window." - Major Payne
Yay guide. :biggrin.gif:
Instead of reserving posts, you can use gotos and anchors.
I'll remember that for next time. I assumed there was a way, but didn't feel like doing any more research...
Quote from Kris18 »
I haven't seen you around for a while, Pianosaurus! How are you?
I fell off the edge of the world for a while, but I've orbited around and come back now. A friend of mine set up a server, which brought me back to the wonders of Minecraft. I guess I just temporarily lost my drive when my pre-biome world became obsolete.
Quote from plastik2k10 »
Within seconds the whole place was burning down. My home since January, in ruins.
I feel your pain, dude. I still suffer from Minecraft pyrophobia, even though I know how it works now.
You are going to do some research on lava right? I've been curious whether it's as I expect or different. My schedule recently don't leave me much time for minecraft right now or I would tinker with it some.
EDIT: Actually rereading the OP, I think I need to clarify this.
From MY testing, THIS is safe:
[] [] []
[] [] []
[] [] []
[] [] []
[] []
Though according to your guide it is not, correct?
This will sometimes work, but frequently not. I suspect you simply got lucky. All my testing was done with a single flame, and that case would normally catch fire.
Warning: Back up your world before trying! I have had complete success with the following methods, but you never know...
Fire
Don't think of blocks as being on fire or not. The important thing to remember is that fire is a block that can only live next to combustible materials. When a block of fire exists, it may spread to any other available block (i.e. a block of air) inside a volume of 3x3x6 meters. There is no checking for available paths, so you can not stop fire from spreading by placing stone blocks in between.
This is where fire may spread, as seen from the side:
[] [] []
[] [] []
[] [] []
[] [] []
[] []
[] [] []
Remember that the fire shown doesn't have to be on the top of a block. It can also be on the side of a block. In the following example, the side of a wooden block is on fire, and all the logs are in danger of catching fire.
[] []
[] [] [] []
[] [] [] []
[] [] [] []
[] [] [] [] []
[] [] []
[] [] [] []
[] [] [] []
Only one of these logs is inside the zone where fire may spread, but the other logs enable the fire to spread to the block on one of their sides.
How to shrink the fire zone
Since fire can only spread to (and replace) blocks of air, you can replace air-blocks with something else to prevent spread. In the example above, logs 5 meters above the fire are in danger, because the blocks underneath are available. By placing the logs one step lower, and filling in the fire zone underneath with something non-flammable, you can save one meter.
[] []
[] []
[] [] [] [] []
[] [] [] [] []
[] [] []
Personally, I prefer not putting a wooden floor above the fire. You wouldn't do it in real life either. Build a chimney instead; it looks better.
When creating a fireplace, you usually place your fire on top of a block of netherrack. To prevent the floor from catching fire, simply block off the sides of the netherrack:
[] [] [] []
Remember that fire can spread indirectly. If you place the block of netherrack one level above the floor, the side of it can catch fire, thus allowing the fire to spread one extra block. In other words, don't do this:
[] [] [] []
[] [] [] []
Edit: Actually, this is probably only true if you are burning something other than netherrack. The sides of netherrack can not be set on fire, and fire never spreads to netherrack. [Thanks to Celaeris for the info]
Remember that half-plates occupy the entire block too. If you want a raised fire, you can surround the netherrack with half-plates just as well as any other non-combustible materials.
Making it even smaller (for permanent fires only)
I don't have a single player world to test this in, so I can only vouch for it in multiplayer. Also, it is dangerous. If you light the fire with nothing combustible touching the fire zone, the game seems to forget that the fire can spread. Maybe it is some kind of optimisation. Therefore, you can simply build your wooden structure after lighting the fire.
Edit: The reason is that fire stops updating after 15 ticks. [Thanks to Celaeris for the info]
I don't recommend this, though. You may be fine with it in single player mode, but in multiplayer, some sod will be sure to come along and put the fire out by accident. Shortly afterwards, he will watch in astonishment at what happens when he tries to re-ignite it.
Another possible problem is that the game may re-check the fire zone based on other triggers. Some forum threads suggest that walking into the fire will cause such a zone check. I wouldn't be surprised if throwing something into the fire did the same.
I will update this post if I find out something more about exactly how this works.
[opblock] [Sheep] [opblock]
[opblock] [opblock] [opblock] Fire: A complete guide to not burning down your house
I reserve this post for now, until I have done some more research. It seems simple enough so far.
[opblock] [Sheep] [opblock]
[opblock] [opblock] [opblock] Fire: A complete guide to not burning down your house
I just build a new wooden house. I'll be experimenting soon… Wish me good luck!
OP, this is for you:
/troll
"Never try to teach a pig to sing; it wastes your time and it annoys the pig." — Robert Heinlein
Works: (frontal view, showing first and second storey wooden plank floor adjacent to downstairs fireplace top)
[] [] [] []
[] [] [] []
[] [] [] []
Doesn't work (most people, including me, were doing this before the 1.3 "fix":
[] []
[] []
[] []
OR
[] []
[] []
[] []
Don't build houses out of wood. If you think cobblestone is so disgusting, just change it with a texture pack.
Back near the end of alpha I did my own experiments in this thread and came up with similar results:
http://www.minecraftforum.net/viewtopic.php?f=35&t=99804&start=30
My fire zone illustration in that thread was larger but that was because my focus was on where a flammable block was at risk and not the blocks of air that a fire could actually occupy. Your explanation is better in that regard.
I never did get around to studying lava as you seem to be. I assumed the fire mechanic may be centered on the lava itself, but never got around to actually testing it. I look forward to your findings.
by c0yote
I tried it with terrible results. I gave my wife my glasses for a second, a creeper showed up and now my wife is pregnant.
Stupid 3D..
That is a possibility, but methinks you shouldn't limit yourself like that. Look at the real world. Some buildings are made of wood. I wouldn't want to limit the diversity in my buildings by not using wood.
That one. It's a 3x3x6 box.
Ah, that would have saved me some time. It seems we pretty much reached the same conclusion.
You should have tried four times:
[opblock] [Sheep] [opblock]
[opblock] [opblock] [opblock] Fire: A complete guide to not burning down your house
"I'm sorry you're just a little ****-ant who can't hold his liquids out in public. Now stop that cryin' 'fore I throw you out that window." - Major Payne
But what about logs?
/troll
Instead of reserving posts, you can use gotos and anchors.
I haven't seen you around for a while, Pianosaurus! How are you?
I'll remember that for next time. I assumed there was a way, but didn't feel like doing any more research...
I fell off the edge of the world for a while, but I've orbited around and come back now. A friend of mine set up a server, which brought me back to the wonders of Minecraft. I guess I just temporarily lost my drive when my pre-biome world became obsolete.
I feel your pain, dude. I still suffer from Minecraft pyrophobia, even though I know how it works now.
[opblock] [Sheep] [opblock]
[opblock] [opblock] [opblock] Fire: A complete guide to not burning down your house
by c0yote
I tried it with terrible results. I gave my wife my glasses for a second, a creeper showed up and now my wife is pregnant.
Stupid 3D..
EDIT: My tests are suddenly behaving differently, and I think I may have been spreading bad info. Deleting the rest of this for the moment.
This will sometimes work, but frequently not. I suspect you simply got lucky. All my testing was done with a single flame, and that case would normally catch fire.
[opblock] [Sheep] [opblock]
[opblock] [opblock] [opblock] Fire: A complete guide to not burning down your house