A popular application for our BoltHold asphalt anchors is to secure carports, garages, sheds, lean-to and similar structures to an asphalt driveway or parking area. A question that seemingly everyone is concerned with is "how many anchors should I use?".

Here is a simple formula (with caveats). Attach the anchors every 4 feet on the periphery of the structure. If the shed measures 12 x 20 feet, its periphery is (12 + 20 + 12 +20) = 64 linear feet. Applying the anchors every 4 feet computes to 16 anchors. If you have a wide garage door on one side, beef up the two corners as you will not be able to place anchors in the middle of the span.

We recommend that all corners be reinforced with the use of 2 anchors. If the plates that attach the posts to the asphalt have 4 holes, use 2 diagonal holes. On mid-span plates you can get away with one anchor, but place it on the outside holes as the wind forces are likely to come from that direction.

About the above mentioned caveats... if you expect winds in excess of 35 MPH, consult the structure manufacturer for their recommendations as to the expected forces on the anchors. We offer a range of BoltHold anchors with different pull and shear resistance. In most applications, our smallest SP10 anchors are more than equal to the task. However, if the building code in your area has special requirements, consult a professional engineer. (Dade County FL residents beware -- hurricane ratings require withstanding 175 MPH winds.)