Why should I use brackets and thru bolts to build my boat dock or addition instead of just wood and lag screws?

Longevity in boat docks is all about joint strength.  A mechanical joint is the strongest possible joint between two pieces of wood.  Your dock will be subject to wave action from wind and passing boats.  The bigger the wave the more torsion pressure that is placed on the joints of your boat dock.  These sheering forces will cause a wood joint constructed of nails, wood screws or lag screws to quickly expand and lose strength.  The best time to build your dock right is the first time while it is still on land where it is easiest to work on.  Repairs made over water are more difficult and can be dangerous so take the time  to do it right from the start. 

The joints that have the most pressure on them are the corners of a boat dock.  The strongest corners are made by using an inside corner bracket in addition to an outside corner bracket.  The inside corner bracket has a strength member that completes the third side of a triangle in the joint.  This design provides the strongest possible connection between the two sides of the boat dock.
  

Another important area in dock construction is the attachment of floats to the dock.  The best way to accomplish this is to use an angle bracket to attach the  crosser to a dock joist and then through bolt the float to the crosser.  This allows the use of a four inch carriage bolt through the float flange and the crosser to making a solid mechanical connection.  Be sure to do this on each corner of the float for small floats and on every flange for large floats.   Here is a picture of the joint using a single angle bracket attached to a joist with a bolt through a 2x4 to connect the float.  For large docks and floats use a double angle bracket through a 2x6 crosser.  If possible align the floats so that the bolt through the crosser can be the same bolt that passes through the angle bracket.
 

 Building a dock is within the skill level of most home owners.  We hope that the information found on our site will help you successfully build your boat dock. 

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