Waterproofing

Waterproof or water-resistant describes objects relatively unaffected by water or resisting the ingress of water under specified conditions. Such items may be used in wet environments or under water to specified depths. Waterproofing describes making an object waterproof or water-resistant (such as a camera, watch or mobile phone).^[1]

"Water resistant" and "waterproof" often refer to penetration of water in its liquid state. Permeation of water vapor is reported as a water vapor transmission rate.

The hulls of boats and ships were once waterproofed by applying tar or pitch. Modern items may be waterproofed by applying water-repellent coatings or by sealing seams with gaskets or O-rings.

In construction, a building or structure is waterproofed with the use of membranes and coatings to protect contents underneath or within as well as protecting structural integrity. The waterproofing of the building envelope in construction specifications is listed under '07 - Thermal and Moisture Protection' within MasterFormat 2004, by the Construction Specifications Institute, and includes roofing material as well as waterproofing materials^{[citation needed]}.

Waterproofing is used in reference to building structures (basements, decks, wet areas, etc.), watercraft, canvas, clothing (raincoat, waders) and paper (e.g., milk and juice cartons).

Waterproofing should not be confused with roofing, as roofing cannot necessarily withstand hydrostatic head, and waterproofing can.

The standards for waterproofing bathrooms in domestic construction have improved over the years, due in large part to the general tightening of building codes.

Construction waterproofing

In building construction, a structure needs waterproofing since concrete itself will not be watertight on its own (but note concrete is easily waterproofed with additives). The conventional system of waterproofing involves 'membranes'. This relies on the application of one or more layers of membrane (available in various materials: e.g., bitumen, silicate, PVC, EPDM etc.) that act as a barrier between the water and the building structure, preventing the passage of water. However, the membrane system relies on exacting application, presenting difficulties. Problems with application or adherence to the substrate can lead to leakage. In the UK these membranes are rarely allowed below ground below the water table.

Over the past two decades, the construction industry has had technological advances in waterproofing materials, including integral waterproofing systems as well as more advanced membrane materials.

Integral systems work within the matrix of a concrete structure, giving the concrete itself a waterproof quality. There are two main types of integral waterproofing systems: the hydrophilic and the hydrophobic systems. A hydrophilic system typically uses a crystallization technology that replaces the water in the concrete with insoluble crystals. Various brands available in the market claim similar properties, but not all can react with a wide range of cement hydration by-products, and thus require caution. Hydrophobic systems use fatty acids to block pores within the concrete, preventing water passage.

New membrane materials seek to overcome shortcomings in older methods like PVC and HDPE. Generally, new technology in waterproof membranes relies on polymer-based materials that are extremely adhesive to create a seamless barrier around the outside of a structure.

Oil-based waterproofing

Oil-based waterproofing is generally used for roof leakage after construction and use only wall. This is like primer.

Waterproofing of objects

Waterproofing techniques have been implemented in several types of objects, going from different clothing products to paper packaging, cosmetics, and more recently, consumer electronics. Even though it is possible to find waterproof wrapping or other types of protective cases for electronic devices, a new technology enabled the release of diverse water-resistant smartphones and tablets in 2013.^[2] The method is based on a special nano-technology coded to be a thousand times thinner than a human hair, that prevents water damage in electronics.^[3] Several manufacturers are now using the nano-coating technique on their smartphones, tablets and digital cameras.

A research published online October 21, 2013, in Advanced Materials, of a group of scientists at the U.S. Department of Energy's Brookhaven National Laboratory, proposed that nanotexturing surfaces in the form of cones produces extremely water-repellent surfaces. These nano-cone textures are 'superhydrophobic' (or super-water-hating).^[4][5]

Waterproofing clothing and tents

Waterproofing for tents, leather and clothing such as Gore-Tex jackets or walking boots once the initial manufacturer treatment has worn out is provided by companies such as Granger's, Fabsil or Nikwax. They work by reapplying the same if not better treatment as the manufacturer. So can often restore your clothing to withstand water as good as new. Some companies manufacture chemical-based waterproofing solutions, but companies like Granger's use environmentally friendly processes whilst still assuring the same improvement in protection. Outdoor equipment manufacturer Karrimor was an innovator in the field in the 1960s, and developed nylon-elastomer fabrics that were robustly waterproof.

Standards

• ASTM C1127-Standard Guide for Use of High Solids Content, Cold Liquid-Applied Elastomeric Waterproofing Membrane with an Integral Wearing Surface
• ASTM D3393-Standard Specification for Coated FabricsWaterproofness
• D6135-Standard Practice for Application of Self-Adhering Modified Bituminous Waterproofing
• IEC 60529-Degrees of protection provided by enclosures (IP Code)
• [British Standards Institution (BSI)] BS.8102:2009 - 'Protection of Below Ground Structures against Water from the Ground'.

See also

Wikimedia Commons has media related to Waterproofing.

• Bituminous waterproofing
• Durable water repellent (DWR) coatings
• Insulation
• IP Code
• Sika AG
• Soundproofing
• Water Resistant mark
• Water vapor transmission rate
• Waterproof digital camera
• Waterproof fabric
• Waterproof paper

References

External links

Look up waterproofing in Wiktionary, the free dictionary.

• Exterior Waterproofing