Many building materials are installed in panels units. The nature of these substrates is that they will have gaps between the panels or units. In order to keep air, water, or other undesirable elements out of the substrates, those gaps must be filled. The substance the gaps are filled with, however, must be able to accommodate any motion the building and substrates undergo. This is why a joint sealant is an important element to building construction.
Several elements conspire to degrade a building’s structure. Moisture can seep into substrates and start to damage materials. Thermal fluctuations cause materials to contract or expand periodically and, if not accounted for, can lead to shifting and displacement of substrates. And, of course, there are the occasional earthquakes that buildings in Los Angeles will have to endure. If the joint and the sealant used to seal the substrates do not account for all these factors, they can fail.
Several types of joints exist, and a contractor must choose the joint sealant that is appropriate for the type of joint. The sealant he uses must be able to withstand whatever forces that are working against the joint. It must also be noted that joint sealant has a limited lifespan and should be replaced at the appropriate intervals.