Simpson Strongwall

Starting a Simpson Strongwall Installation

Concrete saw for a Simpson Strongwall concrete trench

Soft Story Protection after July, 1999

Until July of 1999 it was legal to build garages with living areas above them with shear walls on each side of the door only 32 inches wide.  The 1994 Northridge earthquake proved these narrow shear walls were very unstable and often collapsed.  As a result, companies such as  Simpson StrongTie invented narrow walls called Simpson Strong Walls that, though much narrower, still perform as well as much wider shear walls.  This is proprietary hardware available at building supply stores.

The first  to do is cut through the concrete slab so soil can be excavated.  This is a very dusty procedure and we take care to cover all personal property with plastic.  Simpson Strongwalls still need a structural engineer to determine how much steel and concrete will be required.





 Concrete Trench for a Simpson Strongwall Retrofit

Trench waiting for rebar according to structural engineer’s plan

Once we cut two slots in the concrete, we break out the concrete to expose the ground and then dig a trench as specified by the structural engineer.  Engineering is required in Simpson Strongwall installations.

Massive amount of rebar needed in a Simpson Strongwall retrofit

Rebar in trench, ready for concrete

Next we fill the trench with steel reinforcing. Often these trenches are quite large, depending on the size of the Simpson Strongwall, which can vary considerably.

The steel reinforcing is then attached to the Simpson Strongwall and the Strongwall is then attached to the floor, completing the retrofit process.  Simpson Strongwalls are often used on either side of a garage door opening, either in new construction or in retrofits.


Simpson Strongwall complete installation

Complete installation of a Simpson Strong Wall



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