COMPRESS checks that the anchor bolting entered results in a bolt spacing that meets or exceeds the minimum anchor bolt spacing specified by the user. By specifying the correct minimum anchor bolt spacing, the user ensures that the anchor "pull out" strength meets or exceeds the assumed (metal) strength of the selected bolt cross section. This is required because placing the anchor bolts too close can result in a situation where the anchor bolts "pulls out" of the concrete foundation before the bolts themselves are stressed to the assumed level. A typical recommended minimum anchor bolt spacing is 18" (450 mm).

In design mode, COMPRESS considers the minimum bolt spacing when selecting the number of bolts for a given bolt circle. In other words, the number of bolts placed on the given bolt circle is limited by the minimum bolt spacing.

In rating mode, COMPRESS will report a deficiency (in the Deficiencies Summary) if the anchor bolt spacing entered is less than the minimum spacing specified.