A veteran "Rust" degenerate with 4.5k hours, a rock, and a dream.
While everyone starts the game using small furnaces, they quickly become a burden. They eat up a lot of wood and only smelt three slots of ore. Nearly everyone, even a solo, can benefit from using a large furnace as it takes a fraction of the wood to cook the same amount of ore.
However, large furnaces can only be placed on the ground, and placing them outside will undoubtedly lead to your precious materials getting stolen. Even if you use a compound, sneaky players will always try to get in and take what is yours. That's why many players build a furnace base, no risk and no worry. But because large furnaces can only be placed on the ground and you cannot build over them unless you build incredibly high up, they can be tricky.
Furnace bases rely on two key things to function. The primary one is conditional roofs. While you cannot build over a large furnace, you can trigger conditional roof pieces to cover the furnace as long as you place the furnace first. This is because the roofs themselves don't cover the furnace, but the conditional element that automatically connects the pieces ends up covering it for you. Secondly is floor grills. You can build floor frames over your large furnace and put floor grills in them to prevent people from getting in. This is more expensive than conditional roofs and less secure as the floor grills do not take much sulfur to destroy. For this reason, the dominant strategy with furnace bases is using conditional roofs. However, there are multiple approaches to building a base with roofs.
Conditional Roofs - Comfortable
If you want a furnace base that has space to move around, store items, allow for deployables such as a repair table or workbench, even an oil refinery, then the more comfortable pattern is ideal. It's a bit more expensive, but it offers more utility, making it nearly its own farm base. To build it:
- Build a 2x2 of square foundations.
- Surround each side with 3 triangle foundations as if it were honeycombing, adding just a single wall on the outer part of the triangles with one wall being a doorway.
- Remove the 4 center squares.
- Place a large furnace.
- Build triangle roofs on the outer walls facing inwards.
As quickly as that, your large furnace is covered and secure. Naturally you'll need to adapt the space to your liking. I prefer to turn one side into a 2 single door airlock with a garage door on the inside leading into the furnace room. Another side into a 2 triangle loot room and the tool cupboard. Then use the other 2 sides for extra boxes, sleeping bags, lockers, workbench, repair table, or mixing table. To better understand, check out the images below.
Furnace Base Variant 1
Condition Roofs - Efficient
The smaller and cheaper variant, this furnace base supports just a few boxes and is meant for those who do not wish to use the base for any other purpose than just smelting ore. It's tight, more annoying to build, but very efficient. To build it:
- Build 6 triangle foundations into a circle.
- Build 1 triangle foundation on the outside of each of the 6 center triangles.
- Remove the center circle of 6 triangles.
- Place the large furnace.
- Place walls on the outside of each triangle foundation with a doorway on one of them.
- Build triangle roofs on each wall facing inwards. You will have to jump on top of the furnace or even the base to do this.
From there you are secure. You will use 1 triangle as an entrance, 1 as a small loot room for 2 large boxes, and 1 for the tool cupboard. I prefer to make the entrance a single door and a garage door. For further elaborate, look at the images below.
Furnace Base Variant 2
While conditional roofs were an unexpected consequence of the addition of roof tiles, floor grills were historically the answer to building a furnace base. Using the same footprints as the other two, you can also place floor frames above the large furnace and place floor grills inside those floor frames. You also have the option to use fewer walls and leave your foundations uncovered to save a bit on cost. However, the added cost of the floor grills makes the base cost roughly the same as a base with conditional roofs anyway while leaving it less protected. The floor grill requires a blueprint to craft, metal fragments, and offers the same durability as a sheet metal door. For this reason, it's the worse option than conditional roofs in nearly every way.
There isn't a reason to build the floor grill furnace base, but refer to the images below for a quick display of how they look.
Floor Grill Furnace Bases
There is generally no reason as to why you should use the floor grills variant, but there are pros and cons to the two variants of conditional roof furnace bases. If you want something in-between the two, you can easily expand the six triangle variant into something that supports some extra space for a loot room or whatever you may need which is what I personally do. From there you may consider a double furnace or even more which I personally use as an external tool cupboard. In any scenario, a furnace base is sure to benefit nearly anyone in ensuring your safety while smelting and the security of your loot.