Cement

"A combination of sand and limestone. Used for constructing shelter rooms."

Cement can be found from expeditions in the wasteland. It can also be crafted at the work bench. It requires 2 sand and 1 limestone to craft.

Uses

 * Shelter Room requires 2 Cement
 * Hiding Spot requires 1 Cement
 * Shelter Door upgrade requires 4 Cement for its level 3 upgrade