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Waterstop is a waterproofing material installed or embedded within the joints of concrete structures. Its primary function is to prevent water or liquids from seeping through the joints, which are areas highly prone to leakage.
Waterstop comes in several types, with the most commonly used materials being PVC (Polyvinyl Chloride) and hydrophilic materials that expand upon contact with water, each offering distinct properties and working principles suited to different construction applications.
WHY USE A WATERSTOP?
Although concrete naturally offers good water resistance, an area that requires special attention is the joints between concrete sections. Since concrete cannot be poured all at once during construction, the pouring process must be divided into stages, creating what is known as a Construction Joint. Additionally, certain structures require joints to accommodate expansion and contraction caused by temperature fluctuations or structural movement, referred to as an Expansion Joint. Both types of joints are vulnerable points where water can seep through without a proper waterproofing system.
Waterstop is therefore a vital component for preventing water leakage, installed at the structural joints right from the construction stage.
View Waterstop products from Clevcon
Illustration: Construction Joint
Illustration: Expansion Joint
Working Principles of Waterstop
Each type operates on a different waterproofing principle, divided into two main categories:
Illustration: Using Its Shape as a Water Barrier
Illustration: Expanding Upon Contact with Water
Where is Waterstop Used?
COMMONLY USED TYPES OF WATERSTOP
Waterstops commonly used in construction can be divided into two main types: PVC Waterstop and Hydrophilic Swelling Waterstop, each having distinct properties and working mechanisms.
PVC Waterstop is a waterproofing material made from PVC (Polyvinyl Chloride) plastic blended with plasticizers to provide flexibility, enabling it to accommodate concrete joint movement. It is manufactured in long strips with various cross-sectional profiles to suit different types of joints.
Installation Method
It is installed by embedding the PVC Waterstop into the concrete on both sides of the joint. When water attempts to seep through, it is obstructed by the PVC Waterstop, which lengthens the path and reduces the likelihood of water flowing through the joint. This system relies on the material’s properties and physical shape for waterproofing without requiring expansion upon contact with water.
Cross-Sectional Profiles
ดูผลิตภัณฑ์ PVC Waterstop จาก Clevcon
Hydrophilic Swelling Waterstop is a waterproofing material with the special property of expanding upon contact with water. This type of material is manufactured from substances that can absorb water and swell, such as Bentonite or special rubber with Hydrophilic properties, featuring a compact, easy-to-install strip design.
Installation Method
The Swelling Waterstop is installed along the joint area before pouring concrete in the subsequent stage. When water seeps in and contacts the material, it absorbs moisture and expands, tightening the material within the joint to fill gaps and reduce the likelihood of water seepage. This system relies on the material’s expansion force to block water, unlike PVC Waterstop, which primarily relies on the physical shape and properties of the strip.
View Swelling Waterstop products from Clevcon
How to Choose the Right Waterstop for Construction
Selecting the appropriate Waterstop is crucial because each structure has different joint characteristics and environmental conditions. Consider the following factors:
Waterstop is an essential material that helps prevent water leakage at concrete structural joints, which are vulnerable points often overlooked in construction.
Whether it is the PVC Waterstop, which uses its physical shape and material properties to block water, or the Swelling Waterstop, which expands upon contact with water, selecting the right type for the joint characteristics and environment will enhance waterproofing efficiency and help extend the long-term durability of the structure.
PVC WATERSTOP WELDING METHODS 
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