Korea adds 19mm gypsum board to national standards in building-material revision

South Korea's national standards agency said Tuesday it added a 19mm thickness specification for gypsum board and widened thickness ranges for sandwich panels as part of a revision to three national standards covering construction materials.

The 19mm board was missing from the standard first set in the 1970s even though it accounts for 42 percent of gypsum board in circulation, according to the Korean Agency for Technology and Standards under the industry ministry. KS F 3504 previously listed only 12.5mm, 15.0mm and 25.0mm. The revision keeps those three and inserts 19.0mm.

The change covers KS F 3504 for gypsum board products, KS F 4724 for steel wall panels and KS F 4731 for steel roof panels used in sandwich-panel construction. The revised standards take effect Wednesday.

For wall panels, permitted thicknesses widen from 50mm, 75mm and 100mm to include 125mm, 150mm and 200mm. Roof panels gain 150mm, 180mm, 220mm and 260mm specifications on top of the existing 50mm, 75mm and 100mm sizes.

The revision also narrows the permitted fire-retardancy ratings for insulation from four grades — non-combustible, semi-non-combustible, flame-retardant and combustible — to two, non-combustible and semi-non-combustible, and sets a minimum thickness of 0.5mm for the outer steel facing. The new fire criteria align with technical standards set by the land ministry.

For gypsum board, performance requirements are introduced for fire resistance, thermal resistance and bending failure load, and product labelling moves from the back face alone to the back face or the side so stacked boards can be identified in storage.

The revision began with a request from the Korea Fire-Resistant Building Materials Association, whose members include 46 manufacturers such as SY Panel, Younghwa and Sungwoo Panel System. Industry groups had argued that the 1970s-vintage standards no longer matched what builders use. Fire-resistant gypsum boards are commonly installed at 19mm on site, while sandwich panels range from 40mm to 350mm in practice but were limited under the old rules to three thicknesses.

"This revision of the KS standards focused on reflecting the demands of industry and the characteristics of products used on site in the standards," said Kim Kyu-sung, head of the Korean Agency for Technology and Standards.