Water-resistant or waterproof describes objects which are relatively unaffected by water or resisting the ingress of water under specified conditions. Similar items may be used under water to specified depths or in wet environments. Waterproofing describes making an object water-resistant or waterproof (such as a watch or camera).
"Waterproof" or "water resistant" often refer to penetration of liquid water. Water vapor permeation of is reported as a water vapor transmission rate. Water from condensation is usually separate from "water resistant".
The hulls of ships and boats were once waterproofed by applying pitch or tar. Modern items are waterproofed by applying water-repellent coatings or by sealing seams with O-rings or gaskets.
In construction, a structure or building is waterproofed by the use of membranes to protect contents within or underneath as well as protecting integrity of structure.
Waterproofing is used in reference to building watercraft, structures (decks, basements, flat roofs, wet areas), canvas, clothing (waders, raincoat) and paper (milk and juice cartons).
Construction waterproofing
In building construction, almost all structures need waterproofing since concrete itself will not be watertight on its own. Note that concrete is easily waterproofed with additives. The conventional system of waterproofing involves membranes. This relies on the application of one or more membrane layers (available in various materials like bitumen, PVC, silicate, EPDM and so on). These are acting as a barrier between the water and the building structure and preventing the passage of water. Thus, the membrane system relies on exacting application. It presents some difficulties. Problems with application or adherence to the substrate often lead to leakage. In the UK
The construction industry over the past two decades has had technological advances in waterproofing materials. We can include integral waterproofing systems as well as more advanced membranes and membrane-like materials.
Integral systems are working within the matrix of a concrete structure. They give the concrete itself a waterproof quality. Two main types of integral waterproofing systems exist: the hydrophobic and the hydrophilic systems. In a hydrophilic system a crystallization technology that replaces the water in the concrete with insoluble crystals is typically used. Different brands are available in the market. They claim similar properties, but not all are able to react with a wide range of cement hydration by-products. So they require caution. Hydrophobic systems use fatty acids. They block pores within the concrete, thus preventing water passage.
New membrane materials have to overcome shortcomings in old methods like PVC and HDPE. In general, new technology in waterproof membranes relies on materials with polymers that are extremely adhesive. They are able to create a seamless barrier around the outer side of a structure.
Basement waterproofing
Once completed basement waterproofing becomes very difficult since the water pressure is from the outer side (coming inside from outside). This difficulty arises when a membrane cannot withstand a hydrostatic pressure from within the substrate. And the system fails. Water is able to enter a basement through different means which include floors, joints, walls. Many basement waterproofing systems address these problems. But many systems are available. They vary in cost, effectiveness, and invasiveness during installation process. Protection board sheets are specially used membranes in this field are. Basement waterproofing can be done internally and externally. Basement foundations can be block, brick, concrete, and even wood. So it is important to pick the right waterproofing system for the appropriate foundation. Epoxy injection is one of the effective ways to waterproof cracks in poured concrete walls.
