Hayashi gathered the traditional kawara tiles from a factory in Takahama, a city in Japan with a long history of producing the curved roof tiles from local clay.
Across Japan, a five percent rate of kawara tiles being damaged during production results in more than 65,000 pieces being sent to landfill every year.
Hayashi cuts off the chipped or cracked parts of the damaged tiles and fixes them to a wooden frame that he designed to fit the standardised shape so no nails or glue are required for assembly.
"The smooth curved shape [of the tiles] invites people to sit and it keeps one's posture straight ergonomically," Hayashi told Dezeen.
The designer added that the processes used to manufacture the tiles make them extremely durable and weatherproof so they can be used outdoors.
"Japanese roof tiles are fired in more than 1200 degrees [Celsius], which makes them harder than the ones in Europe, which are mostly fired at around 800 degrees," said Hayashi. "A single chair can support a person weighing up to 120 kilograms."
Other properties that attracted Hayashi to seek out a new function for these redundant objects included the variety of textures and colours that are produced.
"Smoked roof tiles gives an ageing texture to the surface, and colours are created continuously by glazing companies as waste material after they showed them to the clients," said the designer.
The wooden frames can be constructed as single pieces or combined to create long benches with legs of different heights.
Hayashi graduated from Design Academy Eindhoven last year and opened his own studio in the city in December. He is working on projects that explore potential uses for various waste materials from factories in Europe and Japan.
"My biggest wish is to collaborate with factories in each country and apply my design principle to propose unique value and locality of waste material," said Hayashi.
The Kawara project was exhibited as part of the [D3] Design Talents exhibition at imm cologne.
This year's [D3] Contest was won by a storage rail based on a traditional Shaker-style peg board. Imm cologne continues until Sunday at the Koelnmesse exhibition centre.