Building Materials Guide - Build a Bunker

Material Types and Uses

Structural materials—wood, metal, and concrete—form walls, floors, and machine frames for core rooms. Electronics and advanced components gate mid-game Boiler Room and Data Room upgrades. Exact recipe lists shift with updates, but the pattern holds: early rooms want basic mats, late rooms want refined outputs from recycle and boiler loops.

Builder class starts with a Repair Hammer, eight building supplies, and fifty percent better repair effectiveness—huge for teams rushing Power. Designer class trades some efficiency for decorations; pick Builder when mats are the bottleneck.

Store everything in the bunker. Materials left in town vanish when nukes land; materials underground persist indefinitely.

Farming Building Materials

Hardware stores and industrial areas on the town map spawn planks, metal, and tools. Cycle them between nukes even when your immediate build queue looks full—RNG might not repeat the same store layout next time.

The Recycle Room converts duplicate weapons and junk into baseline metal, reducing pure hardware grind. Feed it Rusty Pipes and broken shovels when combat gear is stocked.

Sell excess duplicates through the Sell Room for Scrap, then buy missing mats from traders if time is shorter than another full route.

• Wood — early structural builds, common in residential loot.
• Metal — mid-tier rooms and recycle output.
• Concrete — heavier fortification and late upgrades.
• Electronics — Power, Boiler, and Data advanced recipes.

Materials per Room Phase

Phase one: funnel mats into Power before anything else. Without power, other rooms cannot operate regardless of inventory depth.

Phase two: Sell and Recycle need fewer exotic inputs but still consume structural components—keep farming while selling duplicates for Scrap.

Phase three: Boiler and Data demand refined mats. Maintain recycle queues so builders are not idle waiting for one elusive electronic drop.

Team Logistics

In fourteen-player servers, designate one Builder or loot runner as “mat mule” with sack upgrades prioritized early. Protect mules during returns—losing a full metal haul hurts more than losing a Rusty Pipe.

Cross-reference loot priority tier list when sacks overflow. Drop low-tier food before dropping metal if a room build is active.

Once rooms are complete, materials still matter for repairs, optional Armory and Med Bay upgrades, and extraction prep from the win guide.

Veteran lobbies also stockpile electronics before major updates from Piriyo, since new room tiers or balance patches occasionally demand fresh material sinks. Treat surplus mats as insurance rather than clutter.

Repair and Maintenance Loops

Raider breaches and mutant swarms damage bunker infrastructure over time. Builder and Designer classes carry Repair Hammers with boosted effectiveness—use them between nukes so room functionality never dips during a sell or recycle batch.

When repairs compete with new room builds, prioritize keeping Power and Sell online. A repaired Power Room beats a half-finished cosmetic upgrade every time. Feed repair kits with the same material routes used for initial construction, and recycle broken tools from the Recycle Room when metal runs low.