Linings and Coatings Explained
Understanding the design differences for substrate protection and chemical containment
Linings and coatings are designed to provide enhanced protection for surfaces, substrates and structures that they are applied to.
On the surface, both sound similar, but in reality, there are subtle differences between the two.
In the context of resin and associated reinforcements, polyester, vinyl ester, epoxy and polyurethane resins are also used to create both linings and coating systems. Indeed, in many applications, a resin-based system combined with a reinforcement material – a form of composite – is considered optimal across the construction and chemical processing sectors.
What is a Lining?
A lining is a layer of different material covering the inside surface of a structure. This is often aimed at containing a liquid, gas or solid by protecting that inner surface, often with a resin that demonstrates superior properties to that of the existing surface.
Example linings include those used for bunds, gutters, gullies and other systems. In industrial environments storing aggressive chemicals in bulk storage, bund linings are an important part of secondary containment.
What is a Coating?
A coating is defined as a different material outer surface. This is to prevent external contaminants from entering the structure. Like a lining, a coating is designed to protect a surface or structure, with the key difference being that the purpose is to protect the outside surface. This is often from external factors, like rainfall, pollution, biological and chemical contaminants as well as physical stressors (abrasion, impact, etc). as a means to prevent damage to the substrate and contamination of the contained substance.
A classic example of a coating would be the membrane applied to a flat roof – for instance a fibreglass roof. This is able to accommodate foot traffic, equipment placement as well as being able to keep the underlying structure dry across many decades.
What is Encapsulation?
Encapsulation refers to the covering of an object or a surface entirely in a resin system or equivalent. The resin coating helps to protect the object from external stressors, ultimately acting as a lining and a coating.
Understanding linings and coatings in the context of the underlying substrate
In both instances, linings and coatings are much thinner than the substrate they are protecting. This is often because their purpose is not structural but rather protective. Due to the highly bespoke nature of the ingredients, they are often more expensive and require a level of skill to apply. However, the overall cost savings are often significant when compared to the cost of a full replacement.
We have also outlined the steps needed to create a fibreglass lining.
Waterproofing applications of linings and coatings
Linings and coatings are applied to a range of different substrates and structures. In the construction industry, these range from flat roofs to gutters, apertures and other weathering systems.
Chemical resistance applications of linings and coatings
Unlike waterproofing systems, linings and coatings are used to provide resistance to various chemicals. classic examples include resin floors, storage tanks, bund walls and floors, drainage channels and other bespoke systems.