• Anchors' pull resistance depends on the asphalt's thickness and the distance between anchors if less than 12".
  • The reason is that at closer proximity the anchors are sharing the asphalt resistance area.
  • As an example, although each SP10 is rated at 1,500lbs. in 2.5" asphalt, using 2 anchors spaced 4" apart will yield a group pull resistance of only 2,460lbs., not 3,000lbs. as might be expected
  • However, if the asphalt thickness is 4" instead of 2.5, the group pull resistance increases to 3,936lbs.
  • The calculator below computes the group rating. Note that the distance you should input should be the least distance between the anchors. In the sketch below, it would be L2.