Technical Library

Technical Aspects of Retrofitting a House

Seismic retrofitting requires a good understanding of the kinds of damage that occurs in earthquakes, familiarity with tests done by seismic hardware manufacturers, and the performance qualities of plywood, nails, concrete, and steel. Retrofitting requires an understanding of building codes, both current and older.  Below you will find a series of articles and test reports for seismic retrofit contractors, engineers, and homeowners alike. /p>


The Engineering behind all Designs

Base Shear Formula

Three Foundation Retrofits

Center Foundation Retrofits

Design a Cripple Wall Retrofit

Design a Retrofit for a House on a Flat Lot

Design a Retrofit for a Bolted House on a Flat Lot

Earthquake Resistance of Old Buildings

Rotation and Soft Story Retrofits

As built plans




Foundation Bolts, Characteristics and Capacities

Foundation Bolts

Foundations and Rebar

Useful Hardware

Foundation Bolts and Over-sized Holes

Lag Bolt Shear Transfer Ties

Horizontal Hold Down Hillside Anchors


Square Bearing Plate Washer


Over-Driven Nails

Over-Driven Nails in Plywood

Shear Wall Repair Methods

Shear Wall Repairs with Sheet Metal

Repairs when the Floor has been Repaired with Plywood


Shear Walls

Shear Wall Blocking

Shear Transfer Diaphragm

Shear Wall Framing

Shear Walls Built Off the Side of a Foundation

Plywood Nailing Science

                                                                                                             Research Report 154

Research Report 138-High Capacity Shear Walls

ESR 1539 Non-Conventional Shear Wall Construction

Balloon Framing

Slant Nailed Plywood

Nailing Patterns for Stepped Shear Walls

Shear Wall Repair Methods


APA Double_2x_v_3x_in_Joints


Building Codes and Materials


Building Codes

ACQ lumber

Useful Hardware

Simpson StrongWalls

Existing Materials


The Performance of Drywall in Earthquakes


Shear Transfer Ties












Wood Straps are Better than Steel


The Post to Beam Connection

The Importance to Top Plate Connections in Cripple Wall Retrofits

Foundation Capping

Old Foundation Tests by the Structural Engineer’s Association


The Qualities of Wood published by the American Wood Council


Areas Served

San Jose,Sunnyvale, Fremont,Oakland,Berkeley
And Surrounding Areas


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License Info

Works' Comp RWCC64393236
Contractors Lic #558462
Bond #SC6334450
Liability Ins PCA 1045011
Link to Contractor's License Board