Earthquake Brace+Bolt

You are using an unsupported browser. To fully use all the features of this website please update your browser to IE 10 or later. Alternatively use another browser (Firefox or Google Chrome). Please upgrade your browser to improve your experience.

Program Glossary

Adequately braced - Wood framed cripple walls are considered to be adequately braced if they have been strengthened in accordance with the provisions of Appendix Chapter A3 of the California Existing Building Code.

Adhesive anchor - Adhesive anchors consist of a steel threaded rod or rebar and a chemical adhesive that are inserted into a hole that has been drilled into the concrete or masonry substrate. Adhesive anchors generally use epoxy adhesives.

Anchor bolt - Steel rod threaded on one end that is fixed in concrete (or masonry) to attach a structure to its foundation. (Anchor bolts in new construction are placed in concrete before it cures or hardens. Anchor bolts in existing construction are typically adhesive or expansion anchors).

Applicant - Someone who has applied to become a Participating Homeowner.

Application - The collection of information requested by the Brace + Bolt Program and submitted through the website by Homeowners as a requirement to be considered for participation in the program.

Bearing wall - A partition (wall) that supports any vertical load in addition to its own weight.

CEA Brace + Bolt Program - The CEA Program for qualifying policyholders invited to participate.

CRMP - California Residential Mitigation Program (CRMP) is a joint-exercise-of-powers entity formed by its members, the California Earthquake Authority, a public instrumentality of the State of California (CEA), and the California Governor’s Office of Emergency Services (Cal OES). CRMP is a legally separate entity from its members.

Cement - A fine gray powder that produces a bonding paste when mixed with water.

Concrete - A combination of cement, sand, crushed rock, or gravel. It is used for foundations, slabs and sidewalks.

Continuous perimeter foundation - A foundation, typically constructed of concrete or masonry, that is continuous under the exterior walls of a dwelling.

Crawl space - A shallow, unfinished space beneath the first floor of a house without a basement. The crawl space allows ventilation of floor framing and access to pipes and ducts.

Cripple stud - A short stud that is used in a framed timber wall.

Cripple wall - A less than full height wood stud wall extending from the top of the foundation to the underside of the lowest floor framing.

Drywall - Also known as wallboard, gypsum board, plasterboard, and by the trade name Sheetrock (TM), a wall-surfacing material composed of sheets of gypsum plaster sandwiched between a low-grade backing paper and a smooth-finish front surface paper that can be painted.

Earthquake Brace + Bolt Program - The CRMP incentive program.

Engineered solution - Under California Building Code Chapter A3 an engineered solution is required for cripple walls between 4-feet and 7-feet. An engineered solution is unique to each house.

Expansion anchor (wedge anchor) - A type of anchor that is designed to expand inside the drilled hole in which it is placed; thereby securing itself by the resulting pressure and friction against the sides of the hole.

Foundation - The part of a building or wall which supports the superstructure. Typically made of concrete or masonry in residential construction.

Foundation plate - Used when there is not adequate vertical clearance under a house to properly anchor the mudsill to the foundation with conventional anchor bolts.

Framing clip - A device used to connect wood framing members. Typically used to connect bearing walls to floors and to the roof in residential construction.

General contractor - The contractor with main responsibility for the construction, improvement, or renovation project under contract, and is the party signing the prime construction contract for the project.

House - A single-family residential building (one to four dwelling units) meeting the requirements of Section 4.1 of the Program rules.

House Retrofit Expense - Expenses that a Participating Homeowner incurs in performing seismic retrofit work on a house.

Joist - A framing member that supports a floor or ceiling load in a series of parallel members. Typically a 2x8 (2" by 8") or 2x10 (2" by 10") in residential construction.*

Lateral-force resisting system that relies on poles or columns embedded in the ground - Some dwellings are supported on poles or columns embedded in the ground or supported on concrete piers and do not have any perimeter bearing walls. Without walls below the exterior walls of the dwelling, these supporting poles and columns will be required to act as lateral-force-resisting elements during an earthquake. Dwellings supported solely on poles and columns do not qualify for inclusion in the Earthquake Brace + Bolt program. (Poles or columns supporting decks or porches are not part of the lateral-force-resisting system provided there are walls or foundations below the exterior walls of the building.)

Low-slope site - A building site with a natural slope of 10 percent or less.

Lumber - The product of the sawmill and planing mill by sawing, planing, cutting to length, and grading. 1" stock is sawed to 1" thickness then finished (planed) to final size of 3/4", 5/4" stock finishes out to 1" thickness, and 2"x stock finishes out to 1 1/2".*

Masonry - Building elements constructed of stone, brick, hollow clay tile, concrete blocks, gypsum blocks, or similar materials, or a combination of them.

Mudsill - The lowest sill of a structure. Typically supported by the foundation in residential construction.

Napa Brace + Bolt program - The FEMA-funded incentive program in Napa.

Nominal dimension - The stated size of lumber, such as 2x4 (2" by 4").*

Participating Contractor - A contractor who has successfully completed the education module and requirements on the website.

Participating Homeowner - An owner of a house who is participating in the program.

Planing - The removal of the rough, or excess surface of a wood board.

Post - A timber member set on end to support a wall, beam, or other structural member. Typically a 4x4 (4" by 4") or 6x6 (6" by 6") in residential construction.*

Qualifying Building - A building that meets the specifications detailed in the International Building Code ('IEBC”) Appendix Chapter A3, “Prescriptive Provisions for Seismic Strengthening of Cripple Walls and Sill Plate Anchorage of Light Wood-Framed Residential Buildings, as adopted (by reference) into the California Existing Building Code (CEBC) Chapter A3, 2010 Edition.

Raised floor - A wood-framed floor that is supported or raised up off the ground by either wood-framing (such as a cripple wall) or a concrete foundation.

Rules - Each Brace + Bolt program has separate Program Rules on each program website. They can be found at, and

Shear wall - A wall that has been designed and detailed to resist lateral (horizontal) loads on buildings. Often used in buildings to resist earthquake and wind loads.

Sheathing - The wooden covering on the exterior of walls and the roof. Typically made of 1/2" construction-grade plywood; older homes may have shiplap boards or planks.

Siding - The finish covering of the outside wall of a frame building. It may be made of horizontal weatherboards, vertical boards and battens, shingles, or other material.

Sill - Strong, horizontal wood member at the base of a stud wall. Typically a 2x4 (2" by 4") or 2x6 (2" by 6") in residential construction.*

Sill plate - A horizontal member, or board, laid directly on top of the foundation, to which the cripple wall, or first floor of the building, is connected.

Single-family detached dwelling - A free standing residential dwelling that is not structurally attached to a large, multi-family building. For the purposes of this program the dwelling may have one to four family living units.

Story - A level part of a building that can be used by people for living, work, storage, etc. The roof is not considered a story. An attic space may be considered a story if it has been remodeled for use as a room.

Stud - Vertical member of a framed wall. Typically a 2x4 (2" by 4") or 2x6 (2" by 6") in residential construction.*

Subfloor - Boards or sheet material laid on joists and over which a finish floor is laid.

Unreinforced masonry - A masonry structure that has no steel reinforcing bars embedded in it. The masonry blocks or bricks are connected by mortar.

Washer (Plate washer) - Square metal plates placed between the nut (head) of an anchor bolt and the wood mudsill. The washer acts to clamp the mudsill securely to the foundation. Note: It is now mandatory to use hot-dipped galvanized 3"x3"x1/4" square plate washers under the anchor bolt nut.*

(Chapter A3) - Prescriptive provisions for seismic strengthening of cripple walls and sill plate anchorage of light, wood-frame residential buildings.

Prescriptive standards - This prescriptive provision or plan set is a "blueprint" version of a prescriptive ("cookbook") standard for strengthening homes to better withstand earthquake shaking. When approved by the local building official, the plan set may be used to strengthen older homes without the need for costly site-specific plans and design calculations. This plan set provides a low-cost method to help improve an older home's chances of surviving an earthquake.

*Lumber sizes are "nominal"; the actual finished lumber size will be less than the size indicated.