The Simpson URFP should be the only bolting hardware needed for any seismic retrofit guideline.  The Simpson FRFP (type B connector in ICC 1300/FEMA P-1100) and the similar Type C connector only create confusion and unaffordable retrofits. 

This video describes exactly what Simpson Strong-Tie URFP does, when it can and cannot be used, and how to install them perfectly every time.

When building shear walls and using the Simpson Strong-Tie URFP a decision must be made as to whether the hardware will go over or under the plywood.  This video looks at the method suggested by the retrofit guideline Vulnerability Based Seismic Assessment And Retrofit Of One And Two Story Dwellings and compares it to another seismic retrofit guideline Standard Plan A.

This video looks at a very labor-intensive and never necessary method that uses double blocking when mudsills are buried in concrete. This is only found in FEMA’s Seismic Retrofit of One- and Two-Story Dwellings and is not found in any of the other guidelines.

The Versatile Simpson Strong-Tie URFP Foundation Anchor

The FEMA retrofit guideline P-1100 Vulnerability Based Seismic Assessment and Retrofit of One- and Two-Story Dwellings uses the Simpson Strong-Tie URFP in a few different ways. Here you will learn everything there is to know about this foundation bolt substitute.

They are used when it is not possible to put in standard bolts because there is not enough clearance between the floor and the foundation to use a concrete drill or rotary hammer.

Sometimes the Simpson Strong-Tie URFP cannot be used because the mudsill is embedded in the concrete.  This video shows how the excess concrete can be removed in just a few minutes.

Simpson StrongTie URFP Mis-installation

This is a photograph of a URFP Type A Connector posted by the engineers at Simpson Strong-Tie. Notice how the SDS screws are not in the center of the sill.  Simpson requires the SDS screws to be centered in the sill, otherwise, they have no value according to a letter I received from Simpson Strong-Tie; shown in the video at the top of this page. It shows a complete misunderstanding of how URFPs are supposed to be installed.  If the inventors of the hardware do not know how to install this hardware, you can imagine what contractors do.  I found this on the Simpson Strong-Tie Engineering Blog.

Simspon StrongTie URFP installation jig

This simple jig makes it virtually impossible to is mis-install a Type A Connector. To see how this jig works please watch the video on the URFP at the top of this page.

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