Tool Cupboard, Decay & Upkeep

This page covers everything that keeps your base standing on a Facepunch survival server: the Tool Cupboard (TC), the decay timers that erase unprotected structures, and the upkeep cost that drains your TC every hour. Miss any of it and you log in to a pile of loot bags where your base used to be.

What the Tool Cupboard actually does

The Tool Cupboard is the deployable that grants Building Privilege over nearby structures. When placed and authorized, only players on its auth list can place, rotate, upgrade, repair, or deconstruct building blocks inside its zone.

• Crafting cost: 1,000 wood.
• Privilege radius: privilege is now tied to building blocks rather than a fixed sphere — roughly 16 meters out from the TC along connected foundations, and up to six floors high.
• Auth list size: up to 10 authorized players on vanilla servers. The popular "12 max" figure is incorrect for vanilla.
• Placement rules: only one TC per building footprint; placing a second TC inside an existing privilege zone is blocked. Auth is per-cupboard, not shared.
• Authorizing: press E on the TC to add yourself; press E again while already on the list to remove yourself. Hold E to open the wheel menu — "Clear Authorized List" wipes everyone.

If a structure sits inside no TC's privilege zone at all, anyone can build off it, place ladders on it, or deconstruct it with a hammer during the 10-minute grace window.

How building privilege actually propagates

The single most misunderstood part of the Tool Cupboard is the shape of its protection. The in-game tooltip describes a flat "50 metre" sphere, but that figure has not matched reality for years. Privilege is propagated through connected building blocks, not radiated as a free-floating ball of influence. The TC projects authority into every foundation, wall, floor, and roof that is physically attached to the block it sits on, then a short distance outward from the edges of that connected structure.

• The connected-block rule: a foundation 40 metres away that is bridged to your base by an unbroken chain of building blocks is protected; a foundation 8 metres away that shares no physical connection is not. Privilege travels along the structure, not through open air.
• The edge bubble: beyond the outermost connected block the game adds roughly a 16 metre cushion in which nobody else can build, which is why neighbours cannot wall you in flush against your own foundations. Vertically the protected column runs about six floors high, so a raider cannot simply build a sky-base directly over your roof.
• The authorization list: privilege is meaningless without auth. Pressing E once adds you; pressing E again removes you; holding E opens the radial menu with "Clear List". Vanilla caps the list at 10 players — the widely repeated "12" is wrong. Turrets, SAM sites, and shotgun traps read this same list, so de-authing a traitor instantly strips them of build rights and stops your turrets shooting them.
• De-auth before you log a wipe: the list persists until manually cleared. Players who forget to clear it at the start of a new base hand a former teammate full editing rights over the new build.

Decay timers without a Tool Cupboard

These are the times each material takes to decay from full HP to zero once decay begins. They apply both when there is no TC at all and when the TC exists but is empty of the relevant material:

Decay scales with current HP — a wall at 50% HP decays in half the listed time.

Upkeep cost formula

When a TC is stocked with the matching material, each connected building block pays an hourly tax instead of decaying. The drain is roughly 10% of the block's build cost per 24 hours, paid hourly from the TC, with a free grace period for newly placed blocks (the first ~24 hours of a new block's life are effectively free).

Approximate per-day burn per wall, full HP:

The TC pulls upkeep in priority order: HQM → metal frags → stone → wood, paying only for blocks of the matching tier. If the matching material runs out, the corresponding tier's decay timer begins immediately.

The upkeep formula in full

The hourly bill is not a flat number — it is a percentage of your total build cost, and that percentage swings with how full the cupboard is. Two variables drive everything:

• Footprint cost: sum the build cost of every wall, foundation, floor, ceiling, doorway, and window frame inside the privilege zone, grouped by material tier. A 50-wall stone bunker with its floors and frames might total ~60,000 stone of build value.
• Fill multiplier: while the TC is more than 50% stocked it bills the cheap rate — about 10% of build cost per 24 hours. The moment stock drops below the 50% line the rate ramps toward 30% per 24 hours, so a half-empty cupboard burns up to three times faster. This is a deliberate punishment for sleeping on a thin stockpile.

Worked example for a single stone wall (300 stone build cost):

• Topped TC: 300 × 10% = 30 stone/day = ~1.25 stone/hour.
• Sub-50% TC: 300 × up to 30% = up to 90 stone/day = ~3.75 stone/hour.

The TC drains in real time whether or not anyone is online. Each hourly tick, it deducts the matching tier's cost from the 24 upkeep slots; new blocks enjoy a roughly 24-hour grace period before they start billing. Because the bill is proportional to footprint, every honeycomb layer and decorative wall you add is a permanent recurring tax — large clan compounds routinely burn 5–10× the resources of a tight solo base purely on geometry.

Stockpile slot limits

The cupboard itself has 100 HP, 24 upkeep slots for resources, and 4 tool slots (the tool slots accept hammers, building plans, and the like — they do not feed upkeep). Twenty-four slots sounds generous, but each slot is one stack, and stone stacks far smaller than the daily appetite of a big base. A compound that burns 6,000 stone a day can chew through multiple full stone stacks per day, so slot count — not just total resources — becomes the real ceiling on how long a base survives unattended. This is the core argument for industrial auto-refill: pipes feed the 24 slots continuously instead of you racing the clock to manually re-stack them.

How much upkeep do you actually need

A small 2x2 stone solo base costs roughly 3,000–5,000 stone to build. Daily upkeep on that footprint lands around 300–500 stone/day, plus a small trickle of wood for any wooden frames or workbench supports.

For a mid-size duo bunker (~50 stone walls plus ceilings/foundations), expect closer to ~6,000 stone/day (~250/hour).

24-hour stockpile rule of thumb for safe sleep:

• Solo 2x2 stone: 1,000 stone + 500 wood
• Solo 2x2 metal: 1,000 stone + 1,000 frags + 500 wood
• Duo bunker: 6,000 stone + 2,000 frags + 1,000 wood
• HQM trim only (small): 50–200 HQM/day depending on piece count

Soft-side decay vs hard-side decay

Two separate "decay" mechanics often get confused:

• Material decay (the timers above) applies to every building block losing HP when its upkeep tier is unpaid or it sits outside any TC.
• Twig auto-decay: twig blocks decay quickly regardless, and any twig placed outside a TC privilege zone is destroyed inside roughly an hour — this is by design to prevent twig-laddering raids.

The hard side / soft side of a wall is a different concept entirely — it's the visual triangle pattern. The hard side faces outside (more HP, harder to soft-side raid); the soft side faces in. It is not a decay mechanic, but it does interact with raiding: a soft side facing outward effectively halves the explosives needed to break the wall.

Stacking, refilling, and offline strategy

A TC has 24 inventory slots; stack the materials you actually need in priority order. Best practice:

1. Top of the inventory: HQM stack (if any armored pieces exist), then sheet metal frags, then stone, then wood.
2. Keep all four tiers present, even if your base is mostly stone — losing 3 wooden frames to decay because you forgot to top wood is a real and common death.
3. Industrial pipe auto-refill: since the Industrial Update, a Storage Adaptor can be clipped onto a TC and fed from boxes by industrial pipe + filter. Set one box per material with a Conveyor pushing into the TC. Single biggest quality-of-life upgrade for long wipes.
4. Lock the TC with a code lock — an unauthorized player can still walk up and *withdraw* materials if the TC is unlocked.

Multiple TCs and overlapping zones

Authorization is per cupboard, never shared:

• If two TCs' privilege zones overlap, a player needs to be authed on both to place or remove blocks inside the overlap.
• Building privilege from a second TC will *also* prevent you from placing a third TC in that zone — exploit-proofing against TC stacking.
• Common design: a main TC for the core base, separate TCs for outpost peeks, garage / car bay, and external honeycomb shells. Compartmentalization means a raid that captures one TC doesn't compromise the others.
• Raid behavior: destroying a TC removes privilege immediately, opening the base to outside building. The raider must auth on a *new* TC to claim the structure permanently.

Soft side vs hard side of the TC room

The TC room is the heart of the base, so its walls deserve deliberate orientation. Every triangle and square wall has a textured hard side and a flatter soft side; the soft side takes roughly half the explosives to break. When you build the TC room, confirm that every wall enclosing it presents its hard side outward — a single reversed wall is a soft-side shortcut straight to your cupboard. Walk the exterior in build mode and check each face before you upgrade. Pair this with at least one honeycomb layer so a raider cannot even reach the TC room wall without first chewing through a sacrificial shell.

Hiding the TC and layering locks

A visible, reachable cupboard is a target: destroy it and the base loses all privilege; clear its auth and a raider can lock you out of your own build. Defence is layered.

• Bury it in honeycomb: place the TC in a fully honeycombed pocket so reaching it costs the raider a small fortune in explosives before they can even touch it.
• Decoy cupboards: some builders place an obvious empty TC near the entrance to bait raiders into wasting boom, while the real, stocked TC sits in a buried pocket. Note the placement rule — a second TC inside the same zone is blocked, so decoys must sit just outside the real TC's connected structure.
• Code lock vs key lock: always lock the TC. An unlocked cupboard lets anyone walk up and withdraw your stockpiled materials, and lets anyone authorize themselves. A code lock is the standard — rotate the code, and never reuse your door code on the TC. A key lock is weaker (keys can be looted off a corpse) and is generally only a stopgap. Layer the lock with the room: code-locked door into the TC room, code-locked TC inside, different codes on each.
• Elevate and offset: placing the TC on an upper floor or in an off-centre pocket forces raiders to guess, costing them time and explosives during the raid window.

Common mistakes

1. Sleeping with under 24 h of upkeep — wake up to no walls. Stock at least a full day, ideally two.
2. Forgetting one material tier — a TC full of stone won't save your wooden frames, which will decay first and drop your ceiling.
3. Placing twig outside the TC zone — auto-decays inside ~1 hour; useless for permanent build pieces.
4. Hitting the 10-player auth limit — large clans run out of slots; trim auth list before adding new members.
5. Not locking the TC — anyone authorized (or anyone at all if unlocked) can drain materials.
6. Placing a sleeping bag outside the TC zone — a third party can authorize on it once the original block decays.
7. Building a second TC inside the same zone — the game blocks it; new players sometimes assume their build is broken.

Pro tips

1. Armored is a luxury tier, not a default. HQM upkeep is the most painful material to farm; reserve armored walls for the 1–2 critical chokepoints (loot room door, TC room ceiling) instead of trimming the whole exterior.
2. Put your sleeping bag and respawn point inside the TC privilege zone, ideally inside the TC room itself, so an offline raid can't authorize on you while you're logged out.
3. Industrial-pipe a vending machine or shop box to the TC so you can dump materials from anywhere in the base — refill becomes a single deposit instead of a TC-room ritual.
4. Force wipes wipe TCs and base alongside the map — don't stockpile mats in the TC the day before a force wipe; they're gone with the rest.
5. Decay scales with HP, so a freshly raided wall at 10% HP will be gone in minutes even with full upkeep. After every raid attempt, repair walls back to full before logging off; upkeep does *not* repair damage, it only delays decay.

Sources

• rustlabs / wiki.rustclash — Tool Cupboard
• wiki.facepunch.com — Tool Cupboard, decay and building privilege
• Corrosion Hour — RUST Tool Cupboard: The Basics
• Corrosion Hour — RUST Upkeep Building Guide
• Corrosion Hour — RUST Industrial System Guide
• Rust Wiki / Fandom — Tool Cupboard
• Rust Wiki / Fandom — Decay
• Falcon Rust — Tool Cupboard Building Guide
• Falcon Rust — Upkeep Guide
• Lone Design — Tool Cupboard Guide
• RustBases — Understanding Build Costs and Upkeep
• Facepunch — Industrial Update