Pressure Chamber Not Fitting Foundations

If your Pressure Chamber will not fit on foundations in Moon Sweepers, the first fix is to update. At launch, a building had to sit entirely on a single foundation tile, and the Pressure Chamber is bigger than one tile, so the game rejected it no matter how you arranged the pad. Patch 1.0.3, released on October 24, changed that: machines can now stand across several foundations, so Pressure Chambers, Stone Presses and Garages fit on square foundations.

What to do now:

1. Make sure your game is on version 1.0.3 or later. In co-op, every crewmate must be on 1.0.3 to play together.
2. Build a pad of connected square foundations large enough for the whole machine and its belts.
3. If placement still fails, work through the checks below. The multi-foundation change fixed the tile limit, not every placement problem.

Older guides and threads that tell you to place the chamber only on bare ground, or to keep one building per foundation, describe the launch build. They are no longer the required setup.

Why the Chamber Would Not Fit at Launch

The problem came up within hours of release. Players reported that buildings could not be placed on foundations because they were bigger than a single tile, and the game did not recognise a machine sitting over more than one. A streamer building a base described the same limit in plain terms: you could not build across foundations, so anything that needed more room than one piece would not go down.

Guides written in the first days repeated the workaround: do not place a Pressure Chamber, Stone Press or Packager across the seam where two foundations meet, and place machines directly on cleaned lunar ground instead. That advice made sense for the launch build. It is now outdated for machines covered by the patch.

What Patch 1.0.3 Changed

The 1.0.3 building notes say machines can stand across several foundations, so pressure chambers, stone presses and garages fit on square foundations. The same building section made splitters and mergers snap straight onto each other port to port, and let you place a carried capsule on a belt where you aim.

The change is about crossing tile seams. It does not make the chamber smaller, and it does not promise that every terrain or obstruction problem is gone. One placement guide is careful on exactly this point: the cross-foundation fix does not prove that every terrain or obstruction condition has been removed. If the patch did not solve your case, something else is blocking the spot.

Check your version first

Steam normally updates the game automatically, but a paused or pending update leaves you on the old rule. Before you rebuild your pad, confirm the game has updated. In multiplayer, the patch notes are explicit that all crewmates must be on 1.0.3 to play together, so a mixed group will run into connection problems before placement ones.

Plan the Foundation Pad

Foundations live in the Building Tool's structures section, alongside walls, corners, railings, stairs, roofs and catwalks. The Building Tool costs $50.

Build the pad before buying the machine:

1. Lay connected square foundations covering the chamber's full footprint.
2. Extend the pad on the input side, so the incoming Dust belt has room to approach.
3. Extend it on the output side, so the Sand belt can leave.
4. Keep the pad flat and continuous. Gaps or uneven pieces make it harder to tell why a placement fails.
5. Leave space for solar panels or other power nearby. The chamber needs 10 kW.

There is no official footprint chart or measurement grid for machines, a gap players complained about at launch. The practical way to size the pad is to hold the placement preview over it before you buy anything else and watch whether it fits with room to spare.

Sharing one pad with a Stone Press

Many players build the chamber and the Stone Press side by side, since the press needs the chamber's Sand. Patch 1.0.3 covers both machines, so one larger pad can hold the pair. Plan it as a single layout rather than two separate builds:

• Leave a lane for the raw Dust branch that must bypass the chamber and reach the press directly.
• Put the chamber's output side facing the press, so the Sand belt stays short.
• Keep the press output facing toward the Depot route.
• Remember that the pair needs 28 kW together, so reserve space for enough solar on or beside the pad.

Building the whole footprint first, then placing machines onto it, avoids the situation where the second machine has no room and the first has to be demolished.

Decide the orientation before you confirm

The Pressure Chamber's input is on the side without the handle. Point that side toward the incoming Dust belt during placement. Rotating a machine after it is built has not been established as a reliable option, and one player found that rotation sometimes would not respond while placing. That player's build controls also showed a rotation lock option, so if rotation suddenly stops working, check that setting before giving up on the spot.

Placement Checks That Still Apply

If the game is on 1.0.3 and the chamber still will not place, go through these checks one at a time.

The hex must be cleaned

The in-game Field Manual explains that you have to clean the entire hex before you can build anything on it. One streamer had to finish clearing a hex that was already above 96% before building could start. If your pad sits on a hex that is not fully clean, placement can fail even though the foundations look fine.

Open the Moon Map from the station console to check. Orange is uncleaned, blue is started but incomplete, and green is completed. A field manual entry also mentions a region scan for the area you are standing in.

Something is in the way

Placement and belts both fail when an object blocks the spot. Players saw a "blocked by an object" message while laying a conveyor through a crowded area. Another player could not build in one place until they realised they were standing in the way themselves. Check for:

• Your own character or a crewmate inside the footprint.
• Existing belts, splitters or mergers crossing the pad.
• Walls, railings, stairs or solar panels touching the edge of the machine.
• A parked vehicle near a Garage or collector pad.

The pad is not one continuous surface

The patch lets a machine span several foundations. It does not say a machine can bridge gaps between separate pads or hang over the edge of one. If the pad has a missing piece or the machine overhangs the edge, extend the foundations and try again.

Ground instead of foundations

If you need the chamber working right away, cleaned open ground is still a valid place for it. It was the common launch workaround and nothing in the patch removed it. You can always build a tidy foundation pad later for the next machine.

Avoid Costly Rebuilds

Getting placement wrong costs money. Players at launch reported that demolishing a building returned about 75% of its cost, and that there was no tool to move a placed building. A $500 chamber placed facing the wrong way loses money to fix.

Before buying:

• Hold the preview over the pad and confirm it fits.
• Check the input side faces the incoming belt.
• Check the output side has a clear route.
• Confirm there is power within range.

If you must demolish to rebuild, check the removal preview first. Garages are a separate case: since 1.0.3, demolishing a Garage no longer deletes the vehicles kept there. They move to another Garage or wait for the next one you build. Older warnings to drive every vehicle out first describe the launch bug.

If It Still Will Not Place

When the version is current, the hex is clean, nothing is in the way and the pad is continuous, record the details before trying random fixes:

1. The machine you are placing.
2. The surface: foundations, ground or a mix.
3. The orientation you tried.
4. Any message shown by the placement preview.

That record helps separate the old seam restriction from a different bug, and it is what the developers need if you report it in the official community channels. Meanwhile, placing the chamber on cleaned open ground nearby keeps your production running while you wait for an answer.

What a Working Placement Looks Like

A successful placement has three things: the chamber sits fully on the pad or on cleaned ground, its input side faces a clear incoming belt, and its output side has room for the Sand belt. Send one Dust capsule in and wait for Moon Sand to come out. Once that works, the same pad layout will take a Stone Press or another chamber, since 1.0.3 lets both span square foundations the same way.