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Waterproofing is the process of making an object, person or structure waterproof or water-resistant so that it remains relatively unaffected by water or resisting the ingress of water under specified conditions. Such items may be used in wet environments orunderwater to specified depths.
Water-resistant andwaterproof often refer to resistance to penetration of water in its liquid state and possibly under pressure, whereasdamp proof refers to resistance to humidity or dampness.Permeation ofwater vapour through a material or structure is reported as amoisture vapor transmission rate (MVTR).
The hulls of boats and ships were once waterproofed by applyingtar orpitch. Modern items may be waterproofed by applying water-repellent coatings or by sealing seams withgaskets oro-rings.
Waterproofing is used in reference to building structures (such asbasements, decks, or wet areas), watercraft, canvas, clothing (raincoats orwaders), electronic devices and paper packaging (such ascartons for liquids).
In construction, a building or structure is waterproofed with the use of membranes and coatings to protect contents and structural integrity. The waterproofing of thebuilding envelope in construction specifications is listed under07 - Thermal and Moisture Protection withinMasterFormat 2004, by theConstruction Specifications Institute, and includes roofing and waterproofing materials.[citation needed]
In buildingconstruction, waterproofing is a fundamental aspect of creating abuilding envelope, which is a controlled environment. The roof covering materials,siding, foundations, and all of the various penetrations through these surfaces must bewater-resistant and sometimes waterproof. Roofing materials are generally designed to be water-resistant and shed water from a sloping roof, but in some conditions, such asice damming and onflat roofs, the roofing must be waterproof. Many types of waterproof membrane systems are available, includingfelt paper ortar paper withasphalt ortar to make a built-up roof, otherbituminous waterproofing, ethylene propylene diene monomerEPDM rubber,hypalon,polyvinyl chloride,liquid roofing, and more.
Walls are not subjected to standing water, and the water-resistant membranes used ashousewraps are designed to be porous enough to let moisture escape. Walls also havevapor barriers orair barriers.Damp proofing is another aspect of waterproofing. Masonry walls are built with a damp-proof course to preventrising damp, and the concrete in foundations needs to be damp-proofed or waterproofed with a liquid coating,basement waterproofing membrane (even under the concrete slab floor wherepolyethylene sheeting is commonly used), or an additive to the concrete.
Within the waterproofing industry, below-ground waterproofing is generally divided into two areas:
In buildings usingearth sheltering, too much humidity can be a potential problem, so waterproofing is critical. Water seepage can lead tomold growth, causing significant damage and air quality issues. Properly waterproofing foundation walls is required to prevent deterioration and seepage.
Another specialized area of waterproofing is rooftop decks and balconies. Waterproofing systems have become quite sophisticated and are a very specialized area. Failed waterproof decks, whether made of polymer or tile, are one of the leading causes of water damage to building structures and personal injury when they fail. Where major problems occur in the construction industry is when improper products are used for the wrong application. While the termwaterproof is used for many products, each of them has a very specific area of application, and when manufacturer specifications and installation procedures are not followed, the consequences can be severe. Another factor is the impact of expansion and contraction on waterproofing systems for decks. Decks constantly move with changes in temperatures, putting stress on the waterproofing systems. One of the leading causes of waterproof deck system failures is the movement of underlying substrates (plywood) that cause too much stress on the membranes resulting in a failure of the system. While beyond the scope of this reference document, waterproofing of decks and balconies is a complex of many complimentary elements. These include the waterproofing membrane used, adequate slope-drainage, proper flashing details, and proper construction materials.
The penetrations through a building envelope must be built in a way such that water does not enter the building, such as usingflashing and special fittings for pipes, vents, wires, etc. Somecaulkings are durable, but many are unreliable for waterproofing.
Also, many types ofgeomembranes are available to control water, gases, or pollution.
From the late 1990s to the 2010s, the construction industry has had technological advances in waterproofing materials, includingintegral waterproofing systems and more advanced membrane materials. Integral systems such ashycrete 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 useconcrete sealers or evenfatty acids to block pores within the concrete, preventing water passage.
Sometimes the same materials used to keep water out of buildings are used to keep water in, such as a pool orpond liners.
New membrane materials seek to overcome shortcomings in older methods likepolyvinyl chloride (PVC) andhigh-density polyethylene (HDPE). Generally, new technology in waterproof membranes relies onpolymer-based materials that are very adhesive to create a seamless barrier around the outside of a structure.
Waterproofing should not be confused withroofing, since roofing cannot necessarily withstandhydrostatic head while 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.
Somegarments, andtents, are designed to give greater or lesser protection against rain. For urban useraincoats and jackets are used; for outdoor activities in rough weather there is a range ofhiking apparel. Typical descriptions are "showerproof", "water resistant", and "waterproof".[1] These terms are not precisely defined. A showerproof garment will usually be treated with a water-resisting coating, but is not rated to resist a specifichydrostatic head. This is suitable for protection against light rain, but after a short time water will penetrate. A water-resistant garment is similar, perhaps slightly more resistant to water but also not rated to resist a specific hydrostatic head. A garment described as waterproof will have a water-repellent coating, with the seams also taped to prevent water ingress there. Better waterproof garments have amembrane lining designed to keep water out but allow trapped moisture to escape ("breathability")—atotally waterproof garment would retain body sweat and become clammy. Waterproof garments specify their hydrostatic rating, ranging from 1,500 for light rain, to 20,000 for heavy rain.
Waterproof garments are intended for use in weather conditions which are often windy as well as wet and are usually also wind resistant.
Footwear can also be made waterproof by using a variety of methods including but not limited to, the application of beeswax, waterproofing spray, ormink oil.[2]
Waterproofing methods have been implemented in many types of objects, including paper packaging, cosmetics, and more recently, consumer electronics. Electronic devices used in military and severe commercial environments are routinely conformally coated in accordance with IPC-CC-830 to resist moisture and corrosion but encapsulation is needed to become truly waterproof. 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 waterproof smartphones and tablets in 2013.[3] This method is based on a specialnanotechnology coating a thousand times thinner than a human hair which protects electronic equipment from damage due to the penetration of water. Several manufacturers use the nano coating method on their smartphones, tablets, and digital cameras.
A 2013 study found thatnanotextured surfaces using cone forms produce highly water-repellent surfaces. These nanocone textures aresuperhydrophobic (extremely water-hating).[4][5]
Waterproof packaging or other types of protective cases for electronic devices can be found. A new technology enabled the release of various waterproof smartphones and tablets in 2013.[6]A study from 2013 found that nano-textured surfaces using cone shapes produce highly water-repellent surfaces. These "nanocone" textures are superhydrophobic.[7][8]
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