blocking for railing posts

Structural Framing Considerations for Cable Railings A successful deck installation is dependent on quality materials and good planning . Creating a detailed design and thorough material take off can cut labor hours and ensure all the parts and pieces are available prior to construction. One important detail that is often left out is how to frame for the railing. Framing considerations for cable railings must take in to account the attachment method/s for the railing posts and the necessary blocking thickness needed to guarantee a proper connection.  Mounting Types-  Two of the most common attachment methods for any type of railing system are “Fascia Mounted” and “Surface Mounted” connections. A fascia mounted post is directly attached to the outside perimeter fascia board using a side mounted position. Alternatively, a surface mounted post is bolted to the deck surface using a deck mounted post position. Cable railing posts must be securely attached to framing members and/or structural blocking in order to provide the lateral load strength and resist heavy tension loads from cables. Joisting and/or Blocking- A double rim joist or solid blocking at each post location can be utilized for proper cable railing post attachment. Fascia mounted posts should be attached to a minimum double 2″x8″ timber or 3″ structural material thickness with a height not less than 7.5″. Surface mounted posts should be attached to a minimum double 2×6″ or  3″ material thickness and a width not less than 5.5″ laid flat beneath the deck surface. All blocking should be directly attached to joisting on all sides of each block. The photo (right) gives us a perfect visual of structural backing for a surface mounted deck post installation. Here a 2″x8″ rim joist is backed by a 4×4″ block and sandwiched by another 1.5″ thick block. The blocking is fastened on all 4 sides and provides enough backing material for adjustment in all directions. If you have questions about framing considerations for your cable railing give our pros a call at 844-277-7327 or submit a quote request via the online form.