Sealants are used to close a gap between two parts of the construction, which are frequently made of two different materials for instance:
* a brick wall adjacent to a metal or a wood structure, such as figure 1,
* a PVC window frame placed into a concrete façade,
* glass panels into metal or plastic frames, etc..
Also the parts to be jointed and sealed may have large sizes such as the whole length or height of a façade.
Therefore one can expect large movements between these parts of the building, resulting from temperature and moisture content variations, movement of the soil, movement of the works under its own load, etc… as we will discuss it in the next pages.
In Sealants for Construction Part I, we have discussed the various movements between the elements of the Construction.
Whatever be the movements, the sealant must withstand it without failure, and therefore it must be elastic as we have seen in Sealants for Construction Part II of this chapter.
In this section we will now discuss the design and calculation of the joints and the selection of sealant type in order to meet these movements requirements.