It is at this stage which any adjustments caused by the sulphur dioxide checks are applied to the basic thickness. Manufacturers must next ensure that no slate is thinner than this measurement. Considering slates are sold on the foundation of nominal thickness; in case the range variation is great the nominal thickness will be a great deal larger than the minimum. If variation looks small then they will be much nearer. This process ensures your slates will be technically satisfactory but there is a different route in which it is important for preservation reasons to make use of denser slates. These may be specified based on traditional construction methods. Obviously it can be unwise to use this alternative to indicate thinner slates than required to resist the wind stress.