7 Days to Die Wiki

New Si As of A13.6[ | ]

Information courtesy of Gazz from the official forums[ | ]

Building / Structural Integrity (SI) Tutorial[ | ]

  • This game has physics.
  • Granted, they are more like phunsics, but building things is a lot more challenging than in games without Structural Integrity. (such as Minecraft)

Basics[ | ]

Actually there isn't anything beyond the basics. Structural Integrity in this game is simple.

As of A20, when placing a block, the preview will change color to indicate the effect of adding the block:

  • Yellow – The block is stable. As the block becomes more yellow it means it is getting less stable
  • Red – Placing the block would cause some type of collapse. Adding blocks to reinforce other parts of the structure may allow this block to then be placed without collapse
  • Pink – Placing would cause this block to fall as it does not have sufficient support

Block Formula[ | ]

The tool-tip of a block (like a Building Block) lists
 Max Load: 40
 Mass: 5
  • Translate "Max Load" as "Glue" and you're halfway there.
  • Each of the 4 side faces of this block can hold a mass of 40.
  • So you can attach 8 wood frames to the side of another wood frame. Try it. The 9th won't stick.
  • A metal block has a mass of 20 so you can attach two metal blocks to the side of a wood block.

Vertical[ | ]

Vertical stability is infinite. You can stack 250 stone, tungsten, or concrete on a single Building Block. (then you hit the ceiling of the game)

  • You can build an entire base on a one block pillar if you so desire, although it's not a good idea because your base can fall down when the Zeds take out your pillar.
  • While the material of a pillar is irrelevant when stacking it up, it matters a great deal for what you can attach to the side of it.


  • You can build most of this pillar from wood provided you use metal (like Iron Frames or Metal Trussing) for the pillar block that has to hold a lot of weight.

Some examples with all wood[ | ]

  • Green = pillar. Connects all the way down to Bedrock with 0 air blocks in between.
  • Yellow = supported block. Structural Integrity values apply.
  • Red = Forget it. It's too much mass and the block will not stick. If it does stick you destabilise your construction and get "random blocks falling off"... somewhere.


  • Note that some "wood" blocks are weaker than the regular frame. Shingles are the typical example. Pay attention to tool-tips.

Strike the earth![ | ]

  • No, really, don't... unless you know precisely what you're doing.


  • See what happens? The entire pillar is now a "supported block" instead of supporting other blocks.
  • Tread carefully with your mining/digging, otherwise Fun may ensue.

The Magic 8 Block[ | ]

Fourth Fifth

  • A ceiling / bridge / whatever will break if you step on block #9 from a support and if the ceiling is 1 block thick.
  • Why? Because.

The Game Messing With You[ | ]

  • The new poured concrete is a great example.
  • The rebar frames are metal (320/20).
  • If you "upgrade" them to the wooden cast or fresh concrete level, they will have wood stats (24/5).
  • Guess what happens if you upgrade the pillar to 24 SI while the rest of the construction still has 20 mass per block.
  • It's silly, but you need a lot of temporary supports if you want to use poured concrete anywhere but on flat ground.

Overview[ | ]

WARNING: A lot of this has changed since Alpha 13 and may not be relevant anymore.

Structural Integrity describes how many blocks of one material can be used to build an unsupported structure.
One example for such a structure is a horizontal beam. It is important that the player uses the same block for the base as for the beam itself.
There are some limitations to this.

  • It is not possible to build a beam longer than 15 blocks. The 16th block simply drops and doesn't stick to the beam.
  • A beam longer than eight blocks will partially collapse when stepped on the 9th block. This is also true for platforms; any block further away than 8 blocks from the base will fall if stepped on. Every block between you and the base counts; if you build 3 blocks straight, 2 to the side and than 3 straight again, counts as 8 blocks. Adding any further block and stepping on it will cause it to fall.

Metallic Blocks[ | ]

Contrary to popular belief, Metal Trussing and other metallic blocks do not act differently than, for example, stone blocks. Metallic blocks mostly have a Max Load of 320 and a Mass of 20; what would make a structural integrity of 16, but due to the limitation at 15 it seems like structural integrity for metallic blocks is 15 and they break partially. If the player builds a plateau 4x4 instead of a beam he reaches the 16 blocks maximum and may walk on this plateau. Add a 17th block anywhere and the whole structure collapses.

Calculation[ | ]

In order to calculate the structural integrity, divide Max Load by Mass of the block and round down the quotient.

  Structural Integrity = RoundDown ( Max Load ÷ Mass )

This is the number of blocks you can add at each side of the block. To get the support of a side, a platform has to connect to it. I.e. a wooden frame platform of 4x4 blocks has to connect to three sides of the base, to get support for up to 18 blocks. A platform of 3x4 wooden frames only needs to connect to two sides of the base, because that would be enough to get support for 12 blocks. Not counting in these platforms is the base itself as it does not need any support (obviously), making the effective platform 19 / 13 blocks big. Those platforms do not have to be a rectangle.

The maximum number of unsupported blocks includes those you build on other unsupported blocks. If you build a beam of 4 wooden frames on the side of a base wooden frame, you can add two additional wooden frames on top of any other of the four unsupported blocks (it does not matter if both are on top of each other or on different blocks). Adding a 7th wooden frame anywhere on the beam makes the complete beam fall to the ground.

Examples[ | ]

Bridges[ | ]

  • Metal Trussing pillar will support ,as of Alpha 15b8, a 3x14 bridge of wood frames upgraded to first metal band form connected to three facings of the pillar. The facing pointing away will not add to the structures strength going out.
    (the center row will extend one block)

Using different materials[ | ]

If you use different materials, the number of unsupported blocks is calculated using the following formula

  Minimum of ((MaxLoad of BaseBlock : Mass of UnsupportedBlock) AND (number of unsupported blocks you could add if you had used the same material for the base and the beam))

I.e. concrete (MaxLoad 90, Mass 15) and wooden frame (MaxLoad 36, Mass 6)

a) Using concrete as the base and wooden frames as the beam; in this case you can add 6 wooden frames at the side of the concrete block.
b) Using wooden frame as the base and concrete as the beam; in this case you can add 2 concrete blocks at the side of the wooden frame.

Video Tutorial (Alpha 15)[ | ]

The video below explains the physics of mass and max load for various building materials in detail as of alpha 15.

See also[ | ]