Sedimentary and temperature seams bring in structure of buildings for reduction of probability of destruction of the structure of the excess tension resulting from temperature and sedimentary deformations subsequently. Frequency of arrangement of seams is regulated by building regulations.
Multy-storey buildings of big extent can be exposed to destructions which reason the deformations of design resulting from the draft of soil and temperature changes of the environment are. For the purpose of minimization of the arising tension and prevention of constructive deformations, buildings separate into several separate blocks between which settlement and expansion seams are placed. Along with aseismic and shrinkable, expansion and settlement joints belong to group of movement joints.
The seam represents cavity between building sections which is filled with thermal insulation material for reduction of thermal loss. For minimization of impact of moisture on insulation course, the seam on the perimeter becomes covered with sealant. One seam lying from the beginning of the base to building roof can perform functions temperature and sedimentary.
The expansion seam separates the building into separate parts. The seam begins at ground level and lasts on all height of the building. The base of the structure of expansion seam has no as the designs located underground are practically not exposed to temperature deformations. The step with which in the building expansion seams have to be located is accepted depending on such factors as materials of walls and average temperature during the winter period around arrangement of construction. Rated values of distances between expansion seams are specified in building regulations. For not heated rooms the distance between seams has to be reduced by 20% in comparison with rated values.
The settlement joint is necessary for compensation of difference in loadings which appears owing to the different mass of design of separate parts of the building. So, if the multi-storey building has five-floor residential block and one-storey extension for placement of shop, then each of these parts will put various soil bearing pressure. The difference in loadings leads to various size of shrinkage (draft) of parts of the building therefore without availability of settlement joint there can be crack. Settlement joints are necessary also at construction of buildings which all parts have identical number of storeys. In this case the difference in loadings can arise because of various composition of the ground which forms the basis for the building. The main difference of settlement joints from temperature is that they separate both external part of the house, and its base.