BANGKOK -- A joint venture between Nippon Steel & Sumitomo Metal and Australia's BlueScope Steel is adding capacity in Thailand to produce 50% more sheet steel for construction purposes, with a focus on thin, rust-resistant sheet for the roofs and walls of homes.

Asia's steel market is flooded with overproduction by Chinese producers, and there is little general incentive now to invest in added rolling equipment.

But demand remains strong for value-added sheet boasting excellent durability and corrosion resistance. This is an area where joint venture NS BlueScope Coated Products, or NSBS, excels.

NSBS plans to invest 12 billion yen ($118 million) at a plant in central Thailand's Rayong Province to add new lines for processing thin steel sheet. It will install more equipment for plating the sheet with zinc to prevent rusting.

When the new lines become operational in mid-2018, annual capacity for the steel sheet will reach 470,000 tons.

NSBS has specialty agents in Thailand that can process sheet in detailed shapes and designs according to customer needs. With a network of some 350 companies for metal processing and distribution, it is very competitive in the market for roofing and wall materials. It has captured the leading share of the Thai market for sheet steel construction materials by offering a broad line of products at different price points and promoting its brand.

By adding capacity, the company aims to further increase its share of the market and also use the Rayong plant as an export base to such neighboring countries as Myanmar and Cambodia.