Cement is a key item for unlocking your Bakery and is also needed for completing other various upgrades. Cement can be found randomly when fixing benches in-game. These benches reset periodically to give players the chance to keep collecting these items.

Additionally, as your level increases in early game you will see cement will start appearing more often as a reward in NPC deals, and at level 13 you can get some free cement by participating in the Hempire Cup. When you unlock the global market you can buy cement from other players too, if they have them on sale.

You can also save up enough diamonds to quick-buy the cement you need directly in the upgrade pop-up.