Read our real project case study of an EBB-compliant seismic retrofit in Pasadena. Learn about foundation bolting, cripple wall sheathing, and city permit closeouts.
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Pasadena is famous for its historic Craftsman bungalows built in the early 1900s. While these homes possess incredible architectural character, they were constructed long before modern seismic building codes were enacted. Most sit on unreinforced raised foundations with unbolted mudsills and bare stud cripple walls.
At PiersPro (CA GC License #1110475), we are a certified FEMA Earthquake Brace + Bolt (EBB) contractor. This case study documents a real-world seismic retrofit of a 1912 Pasadena Craftsman home, demonstrating how we bring historic properties up to safety code.
The Challenge: Unbraced 40-Inch Cripple Walls
* The Situation: The 1,650 sq. ft. home had a raised foundation with 40-inch tall wood cripple walls in the crawl space. The mudsill had zero anchor bolts, and the cripple walls had no sheathing, leaving the home highly vulnerable to shifting off its concrete footing during a tremor.
* The Goal: Perform an EBB-compliant retrofit to qualify the homeowner for a $3,000 state grant and a 20% discount on CEA earthquake insurance.
The Solution: Foundation Bolting & Plywood Sheathing
- Preparation: We secured the required building permits from the Pasadena Building Department and cleared the crawl space.
- Bolting: We installed 5/8-inch expansion anchor bolts spaced every 4 feet along the perimeter mudsill, mechanically securing the wood plate to the concrete footing.
- Sheathing: We installed structural wood blocking and nailed 1/2-inch CDX plywood sheathing on the interior face of the cripple walls to create rigid shear walls.
- Venting: We cut ventilation openings in the plywood sheathing to align with the home's original foundation vents, adding mesh screens.
- Closeout: The Pasadena city inspector reviewed the work, signed the permit, and closed the project, allowing us to submit EBB paperwork for reimbursement.
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Mid-Content Call to Action
Is your home prepared for the next seismic event?
Work with a certified EBB contractor. PiersPro handles all drawings, permits, and structural installation. Schedule our $99 Instrumental Diagnostic (credited to your contract) to verify your foundation bolting.
Schedule a Seismic Diagnostic or call (213) 583-6669 to speak with our Pasadena team.
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Frequently Asked Questions (FAQ)
Q1: Did this retrofit change the exterior look of the historic home?
A1: No. All retrofitting work (bolting, sheathing, and blocking) was completed entirely from the inside of the crawl space, preserving the historic exterior stucco and woodwork.
Q2: How much did the homeowner pay after the EBB grant?
A2: The total cost of the engineering, permits, and installation was $4,500. After the $3,000 EBB grant was paid out, the homeowner's net out-of-pocket cost was only $1,500.