Winstone Gypsum is a brand of Winstone Wallboards, a division of Fletcher Building. The company has been operating since 1927 and is predominantly known under the GIB® plasterboard brand. The less known brand Winstone Gypsum was introduced to the market in 1994 in response to enquiries from horticulturists. Gypsum is one of those rare minerals that performs in all the categories of soil treatment.
Winstone Gypsum's main target market is the agriculture and horticulture sectors of the New Zealand primary industries. The mineral Gypsum is used as a fertiliser to supply calcium (23% ) and sulphur (18%) as well as to improve soil properties, counteract acid sub soil with high levels of aluminium as well as sodium levels.
