Joel Cánovas was sipping a beer on a patio in Barcelona when a piece of rubbish caught his eye. A section of hydraulic cement tile - the once-ubiquitous flooring material used in homes around the city for a century or so from the mid-1800s - had been discarded during a home renovation.

Cánovas picked up the tile, and a passion was born. Spotting tiles in dumpsters throughout Barcelona, Cánovas soon began to document his discoveries on Instagram as The Tile Hunter (@i_rescue_tiles).

Hydraulic tiles first appeared in homes in Catalonia midway through the 19th century, and for decades they were a popular flooring material for middle-class families - cheaper than marble, but no less beautiful. To Cánovas, the tiles are a unique form of local art, each with a different geometric or floral design pressed atop layers of cement and sand.

Today, homeowners are swapping out their tiles for modern flooring. Cánovas is on a crusade to save the tiles, which are no longer widely manufactured the old-fashioned way: by hand, using a mould, a hydraulic press and pigmented cement.

When Cánovas started gathering tiles in 2014, he was a casual collector, picking up stray pieces that he would use to make end tables or picture frames. But after a feature in a local newspaper, his phone started ringing off the hook with tips from locals spotting hydraulic left in skips, or homeowners with entire apartments' worth of tile that they wanted taking off their hands.

"Now, it's a responsibility," he says.

His collection today includes more than 30,000 tiles with 1,800 unique designs. After running out of space in his apartment, Cánovas moved his tiles into a small workshop in Gràcia but that space is now overflowing ("You can't even walk in there"), so he recently expanded to a warehouse space outside of the city.

Although Cánovas occasionally sells his tiles to cover the cost of renting storage space - he once shipped 1,800 tiles to an interior designer in Australia - he's more interested in preserving part of Barcelona's history than embarking on a retail enterprise.

Once a month, Cánovas hides tiles around the city and shares clues with his Instagram followers. The game, dubbed Tile Crossing, is like Pokémon Go for tiles, and the winners keep their findings. Cánovas plans to release a Tile Crossing app to facilitate the game and make it easier for his followers to drop a pin when they find tiles for him to salvage.

"I think it will be the first app that serves solely to recuperate a part of our street heritage," Canovas says. "These tiles aren't thought of as part of our heritage, but they should be."

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A post shared by The Tile Hunter (@i_rescue_tiles) on Aug 22, 2017 at 10:44pm PDT