The Simpson StrongTie FRFP ICC 1300 Type B Connector

This is one of many instances where contractors will be sent on wild goose chases looking for hardware that is extremely difficult to find. These videos are convincing proof that this hardware drives up the price to unaffordable limits and is convincing that this hardware should not be part of ICC 1300.

 

This is the Simpson Strong-Tie FRFP, also known as the Type B Connector in ICC 1300 and FEMA P-1100 Standard: Vulnerability-Based Seismic Assessment and Retrofit of One and Two-Family Dwellings.

As you can see only 52 FRFPs were sold over a 3-year period; that is approximately 1 1/2 a month. On the other hand, 6,682 URFP Type A Connectors were sold over the same period or 185 pieces per month. This is because contractors never use the FRFP for seismic retrofitting and have found more effective alternatives. In my own business, I have never had a need for them in the past 25 years.

 

 

This detail from ICC 1300 shows the Simpson Strong-Tie FRFP with a 4-foot-long shim and is illustrated here to show contractors what they should do if the distance between the face of the concrete and the face of the sill exceeds 2 1/2″.  More often than not the gap between the foundation and the sill is not consistent in depth along a 4-foot-long span such that this connection would even be possible.  The screw “length as required to embed 1-1/2″ minimum” does not meet the screw manufacturer’s minimum 2″ embedment requirement.  Here is the full report for the 1/4″ Simpson Strong-Tie Heavy-Duty Connector.  One of the reasons this hardware is used infrequently is because alternate details have been developed by contractors to do the same thing at far less cost.  This detail is another sign that the authors of ICC 1300  may have never done this work before.

 

This is an interesting detail from Appendix Chapter A3 of the California Existing Code.  In order for this detail to be effective, the screw going through the shim into and into the sill must be centered in the sill per the manufacturer’s instructions.  There is no allowance for anything less than that. In order to make that happen a contractor will need to take a protractor and figure out the angle of the concrete face and then go to a machine shop to have the beveled washers made.  1/4″ beveled washers of any size are not available from builder’s supply houses.

The shim is also problematic, it will require that same precise angle on one side of the shim.  It is possible to get kind of close with a Skill saw but nothing close to the precision required here.  As an alternative, the contractor can install a Simpson Strong-Tie URFP and be done with it or use a shim as illustrated below.  Angle adjustments are not necessary because the URFP has adjustable slots for the 1/4″ screws.

Slotted holes for the 1/4″ lag screws allow the angle of the URFP to be adjusted, making beveled washers unnecessary.

 

Here the problem is solved with a short 2 x 4 block.

This is how the problem is solved when there is a short cripple wall.

Here is the Type B Connector (Simpson Strong-Tie URFP) as shown in the catalog. Very rarely will one find a foundation sill flush with the foundation such that it is almost always necessary to use a shim as illustrated above.  This product is used so seldom that the largest builder’s supply in the Bay Area they are a special order item.