This is a screenshot of my current base. I would like to surround it with a wall, so animals and Raiders cannot just enter. I thought about using Sandbags, but they are not very sturdy. So how can I surround my base with Walls correctly, while no roof get's added but still retaining the roofs of the existing buildings?
If you go into the zoning tools (the topmost menu on the right of the Architect menu, where the stockpile and growing zones are), you will find buttons to add/remove "no roof" zones.
These work exactly like zoning tools that you use for the home zone and any custom zone you've created.
The "no roof" zoning will make sure that no roof gets built on the tiles you've selected. This also means your constructor will deconstruct any existing roof.
The "build roof" zoning can make it possible for you to build roofs where your colonists wouldn't automatically build one.
By default, colonists only build roofs over enclosed spaces (rooms). But by explicitly marking a zone as a "build roof" zone, your colonists will always construct a roof there.
Note Regardless what the "build roof" zoning says, you can only build roofs a certain distance (IIRC 6 tile) from a wall/mountain. Changing the zoning does not change that rule.
Similarly, your colonists cannot remove overhead mountain roof, regardless of what the "no roof" zone says.
Once you start using these tools, you'll find some cool uses for them. Here are some that I really like:
- If wild animals keep eating your plants (growing zone), you can build a room and mark it to have no roof. Animals cannot walk through closed doors (unless they are pets), so you can protect your crops from animals but still give them sunlight.
- I build a little room around my geothermal generators to prevent raiders fucking with my power supply. To prevent heat buildup, I make sure a few tiles of the roof are "no roof" area. An unroofed room loses heat quicker than simply building a vent; and this alternative doesn't cost you any materials either. Note: I do not open up the roof directly above the generator, only roof to the side. This prevents the rain from messing with the generator.
- If you're ever faced with a fire in a primarily wooden base, you'll know that the biggest colony killer can be the heat buildup. The pawns lose consciousness while trying to fight the fire and everyone burns to a crisp. if you experience a large fire inside, have someone deconstruct a bit of roof immediately.
- Shooting accuracy increases when the target is well lit, and decreases if the target is in the dark. If you are building a fortified position for your colonists, make sure it is roofed to lower the chances of getting hit by raider gunfire. (Similarly, make sure that the entry point of yuor base if well lit so you increase the chance to hit the raiders). Warning: If you only build a single wood wall and build a roof on top of that; if the wall is destroyed, the roof will collapse and kill/maim anyone under it. Make sure you build a few blocks of wall to prevent that from happening!