According to Official Guinness Records,
The tallest stack of chairs is 5.045 m (16 ft 6.62 in) and was achieved by Han Suining and Haier (both China) on Haier washing machines in Qingdao, Shandong, China, on 23 October 2017.The record attempt was organised by Haier washing machines. 50 chairs were used in the attempt, which lasted almost three hours.
For a complete list of 2017 records, please visit 2017 Guinness Records in China.