The Roof Cylinder is one of those small base-building pieces in Subnautica 2 that does exactly what its description says: breaks up your base's silhouette. It's a Furniture and Decor item, so it won't affect hull integrity or power, but if you care about how your underwater home looks, you'll want it unlocked. The catch is that the recipe isn't available from the start. You need to find a specific Data Box first.
Where do you find the Roof Cylinder recipe?
The Roof Cylinder blueprint comes from a Data Box located in the Hot Sea biome. This is the only source for the recipe, so there's no alternative unlock path. You'll need to explore the Hot Sea, retrieve the Data Box, and open it to add the Roof Cylinder to your buildable list.
Once you've opened the Data Box, the recipe registers automatically. No additional scanning or crafting step required.
Habitat Builder placement view
What materials does the Roof Cylinder need?
This is one of the cheapest builds in the game. The Roof Cylinder recipe requires just 1 Titanium, making it essentially free once you have any amount of base resources stockpiled. Titanium is one of the most common materials you'll gather early on, so cost is never a limiting factor here.
Building it follows the same process as any other base piece: equip the Habitat Builder, find a valid placement location inside or on your base, then hold Left Click (PC), RT (Xbox), or R2 (PlayStation) to consume the material and place the piece.
What is the Roof Cylinder actually used for?
The Roof Cylinder is a decorative piece classified under Furniture and Decor. Its in-game description calls it "a small object to break up a base's silhouette," which is accurate. It adds visual detail to the exterior of your base structures, giving them a more complex, layered appearance rather than the flat-topped look that plain corridor segments produce.
It has no functional gameplay effect. It won't increase your base's oxygen supply, structural integrity, or power output. Think of it as the finishing touch once your base is operational.
Don't prioritize hunting for the Roof Cylinder Data Box early in your playthrough. Survival resources like oxygen, power, and materials for key tools should come first. The Hot Sea biome can be dangerous for unprepared players.
Roof Cylinder on base exterior
Building a better base beyond decoration
If the Roof Cylinder has you thinking about base aesthetics, you're probably at a point in the game where your core survival loop is stable. That's a good sign. A few other things worth looking at once you're in that position:
- Power management becomes a real concern as your base grows. Knowing how to keep things running efficiently matters more than any decorative piece.
- Resource farming for Titanium and other materials scales with base size, so planning ahead saves time.
- If you haven't sorted your oxygen situation yet, the guide on how to unlock the Portable Oxygen Generator walks through scanning fragments in the Great Jaw core and the exact crafting requirements.
For everything else you need across base building, resources, and progression, the full Subnautica 2 guides collection has you covered.