Concrete Materials

**Versioning**

This article is considered accurate for the current version (1.52) of the game.

Concrete's in-game icon.

**Concrete Materials** (aka "concrete") is a valuable building material only used to build Concrete Structures, such as Tier 3 Trenches and Bunkers, as well as Storm Cannons and Intelligence Centers. Previously they were considered a building material, like Basic or Refined, even if they did not stack in your inventory. Now, they are a Large Material (like Sandbag). Meaning they can be placed in a pallet and transported as such.

Produced in a Concrete Mixer, or in a Coal Refinery with a Coal Liquefier upgrade. (both structures have different recipes to produce concrete)

## Production

Concrete Materials can be obtained through two ways: the Concrete Mixer or the Coal Refinery with a Coal Liquefier Upgrade.

* The Concrete Mixer refines Components at a 20:1 rate, taking 20 seconds to produce 1 Concrete Material. Available at around the start of the war.
* The Coal Refinery with the Coal Liquefier Upgrade requires 300 Coal and 50L of Water to produce 1 Concrete Material
	+ Produces Oil as a byproduct
	+ Locked behind T2 Facilities in the Tech Tree

## Building

Concrete Materials are the building resource needed to upgrade structures to tier 3. In order to upgrade the bunker to Tier 3, the tech for it has must unlocked in the bunker base's tech tree.

Every structure built with concrete must dry for 24 hours after being built before it can be used, such as upgrading to various bunker structures like the AT Gun Garrison. It is vulnerable while wet but is much stronger than non concrete structures afterwards. The vulnerability depends on how wet the concrete is, as wet concrete that's just been placed takes 10 times more damage than dry concrete; effectively making it about as weak as a tier 1 bunker piece.

Building with concrete materials is different from Basic Materials as the concrete is a large material and doesn't stack. You will then spend less time holding `left click` to build as concrete is a large item and only needs you to submit it, but you will spend a lot more time traveling back and forth between the concrete mixer holding your concrete and your construction site.

## Tips

As Large Items, a soldier can only carry one at a time, on their shoulder. An Engineer Uniform does lower its encumbrance, but you are still only able to carry one at a time. You can press `V` to either pick one from the ground, drop one, or submit one to a nearby structure. You can force drop one by pressing `Shift + V`. As the concrete stacks onto pallets you can move a large amount (120 per pallet) close to your construction site with a crane. As concrete can be dropped to the ground, you can drop several on the ground in certain locations to improve workflow, such as:

* Empty a truck from concrete and drop all on the ground by pressing `left click` on each bag inside the truck, with each `left click` causing you to drop the previous bag where you stand. This allows the truck to go get more concrete at the same time as a soldier moves the concrete on the ground to the construction.
* Dropping and stacking concrete at the edge of a trench and then picking it up from within the trench, cutting out many climbs up and down the trench when moving to the construction site.
* Dropping and stacking on a location with a tight squeeze where a soldier cant fit and then pick it up from the other end, allowing you to skip many trips walking around a particularly inconvenient area.

Alternatively you can instead carry a Concrete Mixer where you will need them, and transport components to refine into concrete there instead. A Resource Container full with 5000 components will let you craft 250 concrete materials, or over 16 times more than by truck and over twice the amount of a pallet.