Installing railings on top of and behind segmental block retaining walls has traditionally been a difficult task for Engineers. Connecting the railing post to the top of the wall is usually not an option because segmented walls are not monolithic. Conversely, a cast-in-place concrete wall can use the total mass of the concrete cantilever to withstand the force on the railing.
The International Building Code (IBC) calls for railings behind retaining walls 30 inches (75cm) above finished grade or taller. Additionally, that railing must be designed for a loading of 50 plf and a 200 lb post load. To meet these loading requirements, retaining walls using smaller segmental blocks must use alternative methods. The methods include (1) requiring the railing post be installed at least 3’ behind the face of the wall and (2) using an engineered post foundation sleeve that is installed during wall construction for post locations up to 6” behind the back of the blocks.
Using Recon, Engineers have more options. Posts can be attached to the top of Recon walls. Recon has done load testing on posts installed into the top of the Recon walls and we have methods to meet these requirements. Based on this testing, Recon developed the 39in(100cm) top block. Railings or Fence posts can be attached to the 39T(100T) top block and meet the IBC requirements. Additionally, methods were developed to attach a Full High Cap (FHC) block to a 39in(100cm) middle block. This is another way to meet the IBC requirements.
Railing posts must be attached to Recon blocks using an anchored base plate. Recon railing details that require connected Recon blocks can be done in three ways:
- 1) Grouted rebar inside 4-6in (100-150mm) diameter holes. Using this method we recommend Recon blocks be made and delivered to the site with the holes in them.
- 2) Epoxied rebar inside post construction drilled holes. Proper removal of dust and debris is required.
- 3) Steel attachment brackets.
All three methods allow for the railing posts to be installed after wall construction and the post spacing can be adjusted in the field by the installer.
Having the ability to install the railing or fence on top of the Recon wall is beneficial. It prevents people from accessing the top of the wall, it allows for sidewalks to be installed up to the back of the wall, and lawn maintenance is easier with grass up to the back of a Recon block.