The carport calculator is a tool that suggests the type and quantity of BoltHold asphalt anchors to be used for securing a carport to asphalt. Please read the notes below before using this calculator.

  1. Asphalt Anchors Corp. assumes no responsibility as to the suitability of the recommendations for the end application.
  2. The calculator only considers the loading and forces on the posts due to wind. Forces such as the car hitting a post are not considered.
  3. Entering a realistic high wind speed is essential. Obtain the value by searching the internet "highest wind speed in xxxxx" where xxxxx is the zip code of the area.
  4. 75 mph high wind is now the minimum norm.  We suggest entering a wind speed of 90 mph if no data is available.
  5. It is assumed that the structure is freestanding and has no side walls.
  6. The calculator provides information pertaining to ONE post, and assumes that the load is evenly distributed among all the posts.
  7. The pull resistance ratings of the anchors used in the calculations are derated for extra safety.
  8. The calculator ignores the weight of the carport. The weight reduces the uplift and shear forces on the posts. This means that the recommendations of the calculator are conservative, offering an additional margin of error.
  9. The dimension d (spacing between mounting holes) is quite critical.  Having a larger "d" reduces the strain on the anchors.
  10. The dimension D between adjacent holes needs to be at least 2"
  11. Please be aware that the SP18 anchors require hole diameter of at least ½", and the SP58 requires at least ¾" holes.