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FRFP Flat Retrofit Foundation Plate


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The FRFP is designed to connect the mudsill to the foundation and provide lateral load resistance. This flat retrofit foundation plate features a design that allows the designer to maintain prescriptive requirements. The FRFP can be used by filling the three round holes, or as an alternative, filling two optional triangle holes to allow designers increased loads and greater spacing.

Key Features

  • Made from durable galvanized steel for lasting and reliable use and to resist corrosion
  • Optional fastening options provide design flexibility
  • Increased loads for wind or earthquake loading
  • Can accommodate up to a 1 1/2″ offset sill plate


  • 8 gauge


  • Galvanized (G90) or hot-dip galvanized; see Corrosion Information


  • Use all specified fasteners; see General Notes.
  • FRFP shall use a minimum Strong-Drive® SDS Heavy-Duty Connector screw length of 2 1/2" plus the shim thickness. Follow code requirements for predrilling. Fasteners are sold separately.

Related Literature

Product Information Table

Fastener Production Information and Stuff & Things
Model No. Ga. W (in.) H (in.) Coating/Material Packaging Qty.
FRFP 8 9 7 Zinc Galvanized, G90 1
FRFPHDG 8 9 7 Hot-Dip Galvanized 1

Load Tables

    These products are available with additional corrosion protection.

Model No. Fasteners Allowable Loads DF/SP (160)
Anchor Bolt Sill Plate
Qty. Dia. F1 F2
FRFP 2 1/2 (3) 1/4" x 2 1/2" SDS + shim thickness 1,065 320
2 1/2 (5) 1/4" x 2 1/2" SDS + shim thickness 1,810 320
  1. Allowable loads have been increased for wind or earthquake loading with no further increase allowed. Reduce where other loads govern.
  2. Each anchor bolt requires a standard-cut washer. The Simpson Strong-Tie® Titen HD® heavy-duty screw anchor does not require a washer.
  3. Nominal embedment depth for post-installed anchors into concrete must be 4" for SET-3G™ or AT-XP®, or use THD50400H Titen HD® screw anchors. Anchorage into CMU is per designer.
  4. For redwood mudsills, reduce F1 on FRFP to 820 lb. (1,395 lb. for five screws).
  5. For installation on SPF/HF sill plates, use 0.86 x DF/SP allowable load.

Prescriptive Spacing for FRFP to Replace Sill Anchor Bolts

Number of Building Stories Anchor Bolt Size Anchor Bolt Spacing FRFP with Three Fasteners FRFP with Five Fasteners
One story 1/2" dia. 6' o.c. 6' 6'
5/8" dia. 6' o.c. 4'–3" 6'
Two stories 1/2" dia. 4' o.c. 4' 4'
5/8" dia. 6' o.c. 4'–3" 6'
Three stories 5/8" dia. 4' o.c. 2'–10" 4'
  1. "Prescriptive" denotes spacing requirements per the IEBC and designs per the IRC and conventional provisions of the IBC.
  2. Spacing is based on the parallel-to-plate load direction.
  3. 5/8" anchor bolt required for Seismic Design Category E.

Code Reports & Compliance