Reinforcing Techniques for Walls

by Bruce Montgomery Ph.D. July 07, 2016

Reinforcing Techniques for Walls

The main purpose of a grab bar is to support a person’s weight as they are standing still or moving vertically or laterally. Assuming that you are using an ADA compliant grab bar that will be located in the proper location for the specified user, your most important task is to ensure that the grab is installed securely.

According to the Fair Housing Act, "covered multifamily dwellings" must contain reinforcements in bathroom walls to allow later installation of grab bars around toilet, tub, shower stall and shower seat, where such facilities are provided.

The full text and drawings of Chapter 6 of the Fair Housing Design Act Manual “Reinforced Walls for Grab Bars” can be downloaded at and is briefly reviewed in our blog called “Reinforcing Walls for Grab bars per the Fair Housing Act”

You can install grab bars to studs through tile, sheetrock or other wall material that is tight to the studs but you must hit the studs at each end of the grab bar with at least three screws at the depth recommended by the grab bar manufacturer. Always follow the installation instructions provided by the grab bar manufacturer. Although every room and its framing are different, most houses have wall studs that are 16 inches apart on center. Therefore, if installing grab bars into studs, you will need to use grab bars with incremental 16 inch lengths to anchor the ends into studs.

The remainder of this blog covers specific ways to add reinforcement to walls that are exposed - that is where the outer wall material has been removed and the wall studs are exposed.

  1. Installing into blocking or cleats. A solid wood block or cleat can be installed on the outside or between studs at the desired height – bottom 30” from floor and top 38” from floor. If you are putting a cleat across three studs and want the cleat to be flush with the outside of the studs, then you can recess (let into) the cleat into the middle stud and screw the ends of the cleat into the insides of the two end studs.   Often a 2” x 10” solid wood board is used as a block or cleat.

Always make and keep a drawing of the location of the blocks for future reference.

  1. Whole Wall or Large Area Reinforcing with Plywood. It may be necessary or desirable to extend the reinforcing over a larger area or throughout the entire wall. A larger reinforced area provides greater flexibility in placement and easier installation of grab bars.

Heavy plywood applied to the studs over a larger area can support grab bars and provide a base for the installation of finish materials such as ceramic tile or plastic wall panels. Plywood can be applied to the face of studs or “let in.” In either case the plywood must be of sufficient thickness and should be securely attached to withstand the forces specified in ANSI 4.24, or an equivalent or stricter standard (typically ¾” or thicker). Anchors for securing the grab bars to the reinforced walls should be through-the-wall type or another type capable of meeting the ANSI force requirements.

  1. Molded Fixtures. Fiberglass and acrylic bathtubs and showers with integral wall panels are common in both new construction and remodeling. The panels alone are too thin to support grab bars, and because they do not touch the stud wall except at the top, there is a space between the panel and the stud wall. To attach grab bars to these surfaces, an area of solid wood blocking or other solid substance must be installed in the cavity between the fiberglass or acrylic wall and the wall.

Since the space between the panels and the stud wall gets narrower as it approaches the top of the panels where they are fastened to the studs, this blocking must be cut to fit snugly in the space between the studs and the panel. The blocking must contact the plastic panel over the entire reinforced area.

NOTE: Some fiberglass and acrylic tubs, showers, and wall sections are now made with reinforcing already in the walls to stiffen the fixture. If the reinforced fiberglass or acrylic wall is not specifically labeled as built for grab bars and meeting the ANSI load requirements, then additional reinforcing may need to be installed.

To ensure that you are complying with all of Chapter 6 of the Fair Housing Design Act’s “Reinforced Walls for Grab Bars”, please download the chapter at

You can find frequently asked questions about grab bar reinforcing at

See our blog called “Location Guidelines for Wall Reinforcing per the Fair Housing Act” for additional information about wall reinforcing.


Bruce Montgomery Ph.D.
Bruce Montgomery Ph.D.


Dr. Bruce Montgomery is a licensed building contractor in Michigan and Florida. He is a Certified Aging-in-Place Specialist as designated by the National Association of Home Builders. He has also achieved an Executive Certificate in Home Modification from the University of Southern California. He has a wide ranging educational background, including a Master of Science degree in Entomology, with a Master of Science degree in Forestry and a Ph.D. in educational administration.