In V Rising, one of the keys to survival is avoiding the sun. This can be done by sticking to the shadows during the day. However, building a roof over your base will allow you to work freely during the day and provide passive bonuses to crafting.
How to construct a Castle Room
To build a roof, you will first need to create a room surrounded by reinforced walls. These are in your crafting menu under Castle, Walls, Reinforced Wall. You can add doorways and windows to this room, provided they are using the reinforced framework. You will then need to cover the entire floor with castle flooring, found under Castle, Floors, Castle Flooring. You can use any type of flooring, but every square between the reinforced walls must be covered with flooring. Once you've done this correctly, the game will automatically construct a roof above the room.
You should house your crafting stations inside this room, as you'll receive bonuses for crafting if you do. If your crafting station is in a confined castle room, you receive a 25% bonus on crafting and refinement rate. Once you've unlocked Forge Floors, you should change to this flooring type. It gives you a 25% reduced cost toward crafting an item.