JOINTS in SURFACE FINISHES
Post 469 by Gautam Shah
Joints are very important section of a surface finish. Joints create pattern, texture, contrast, equalize variegated colours of the surface, endow a discipline and unity, create an orientation, divide a space into proportioned sets, provide flexibility, prevent or direct cracking. A surface finish gains its value as much for the quality of the surface as the careful design consideration for the joints.
Joints in a surface system arise as the components of the surface finish has smaller size than the space, fixing becomes easier and of assured adhesion, and to help divide work schedules. Surface-finishes are applied coatings with on-site application also need scheduled joints to manage continuity. Such depositions, though known as seamless or joint-less system, have nearly imperceptible joints. These joints always have some inherent drawbacks of quality or consistency.
Designing a joint in surface system is a followup process after the surface components have been devised or accepted. In a good design Joints are never of secondary importance. In creation of assembled entities joining is an integrated effort. For all systems joining, un-joining and rejoining, are important strategies of design.
Joints occur with or without a material in an assemblage Fused joints (by chemical solution or heat fusion) have a traceable joint. Edge to edge joining is, both created and avoided intentionally. Wooden floorings for decks (exterior) and stages (interior) have spaced joints to allow the wood to adjust to the changes in moisture content of air. Similarly metal assemblies have free joints to accommodate the expansion caused by the temperature. Edge joints have an intervening material (such as a ductile or conductive material) or none, to allow or curtail the transmission of energy and vibratory forces (mechanical, sound, electrical, etc.). Structures require separation joints to sustain their integrity, and the same are identically placed in their surface finishes.
Very closely placed joints create a virtually continuous surface finish. Stone masonry and wood often have very thin or knife edge joints. Thin joints are for sensorial reasons like touch, fill, visual, etc., and for structural or functional causes. Thin joints provide some flexibility to the surface component, but there is insufficient space for displacement such as in bricks and cobble stone flooring.
Widely spaced joints occur for many different reasons. The prime reasons are: non matting planes at the joint, geometric deviations of the surface components’ shapes. Deep joints require greater width for filling up. Wide unfilled or shallow filled joints create crevices, enhancing the light-shadow contrast over the surface.