Scud Building Material (Patreon)

Figuring out nice sustainable building materials for a species that lives in vast puddle of aggressive solvent has been interesting! 

They use basically no metal aside from easily wrought ones like gold, and metal ore refining is a very new and dangerous science that can only be done on land. Wood is pretty rare as a building material except for scuds who live right by or on the land, as it's prone to heavy wear and or... melting after a while. 

Shell is basically the next best renewable biological building material, and although the weight isn't an issue underwater it's still much more brittle than wood and greater care must be taken during drilling not to shatter it.