However, if the connectors are in line, it does lead to a more complex installation as the beams cannot be installed simply by sliding the connector together. The installation will require a lateral movement first then the beam may be dropped. This method also requires having enough space between the two plates to allow the bottom collar bolt from the supporting plate to be laterally slid in position.
For this reason, we recommend slightly staggering the plates in order to allow enough space for the collar bolt to have a clear travel path from top to bottom, enabling a simple drop-in installation (as shown after [picture below]).
A very important point to consider when using connectors on top of each other is that reinforcing screws should be used. The number of screws required depends on the connections load.
The reinforcing screw should be designed as if the bottom connector plate was non-existent. At least 2 reinforcing screws per connecting system installed this way should be used to ensure that the all the wood fiber along your connection is properly engaged avoiding wood related failure such as beam splitting.
As a general design note, the connector plates should always be installed as low as possible into the beam section, reducing the need for reinforcing or if required (as for staggered connectors), reducing the length of the reinforcing screws.
This installation video
of the First Tech Project in Portland shows this method in use.