Waterproofing Situation in Yunnan Province - China Waterproofing Highlights

Waterproofing Situation in Yunnan Province
Aug. 2006, Kunming
(compiled and composed by Eric J. Chen)

The Waterproofing Association of Yunnan (south-west province of China) carried out a general study, from January 2005 to July 2005, on the status of waterproofing in construction in the province. The survey covered seven major cities of Yunnan. The subjects of the investigation are the waterproofing projects finished from 2000 to 2004. Two main parts of the investigation lie in the quality of project and the materials used. Waterproofing quality of roofing system, basement, bathroom and kitchen, and external wall are main concerns during the investigation. In the first time, such a general and relatively entire look-into of the waterproofing projects in Yunnan was conducted.

Waterproofing quality of roofing system is improving in the province. Among the total 435 projects, the leakage rate, when calculated in area, is 0.85%, and is 15.4% when calculated in number of projects. The leakage rate of Kunming, the capital city, is still high with a rate of 14.7%, the report said. On the roofs, calculated in area, over 61% of the projects used roofing membrane, compared to 32% of those used coating and 7% powders or other materials.

In the aspect of basement waterproofing quality, some 35 projects were studied in the surveying, with a leakage rate of 22.9%. Among these projects, calculated in area, some 62% used roofing membrane, some 38% used coating materials, and the rest took no waterproofing measure.

Among bathroom and kitchen waterproofing projects, the leakage rate is 2.1%. Some 26% of the projects used roofing membrane and some 74% used coating materials. Concerning the tight space in bathroom and kitchen, the use of coating materials, most acrylic acid or polymer modified cementitious waterproofing coating, is more popular.

External wall waterproofing has not been introduced in most among those surveyed in the study. Most of the construction used ceramic tiles or other wall-covering bricks, leading to a considerable leakage situation in this rainy region. Among the few projects having waterproofing, coating materials were used, some imported.

The major part roofing membranes projects used is SBS roofing membrane and PVC roofing membrane

The report said that the quality of the waterproofing had been increased in the last 15 years. The leakage rate decreased from over 50% to about 15% or even 1% after remediation.

As a common phenomenon, lack of regulation effort of the market and the fierce competition among manufacturers lead to low price of the waterproofing materials, whereas the raw materials price keeps growing ranged from asphalt to resin. The market full of counterfeit goods and the contractors without sufficient skilled waterproofing workers are the other two pullbacks of the industry.