Guardrail Guidelines

By December 1, 2015Tip of the Month

Tip of the Month – December 2015

Guardrail Guidelines. 

Are my guardrails safe or could they fail? There are many regulations within the California Building Code that are designed to prevent falls or other injuries from occurring to both children and adults with balcony guardrails. Current California Building codes call for a minimum height of 42″ from floor surface to the top of the guardrail. Prior to 2007 the code was 36″ but this was changed because at 36″ most people who are over 5’9″ can hit a railing at 36″ and fall over the railing due to their pivot point at the hip where a railing of 42″ would hit most people above the hip or waist area and would more likely prevent them from falls or other injuries. The height of the guardrail is different than the height of the stair railing since stair railing is meant to be at arms length, acting as a balancing tool while climbing up or down stairs.


When building a new guardrail system there are 3 important codes to follow in order to meet all current California Building Codes: guardrail height, maximum spacing between balusters and bottom rail and load requirements. For railings that were built before 2007, they are considered grandfathered in and do not need to meet these requirements, though it is highly recommended that you bring them up to code.


Baluster or picket spacing codes are ones in which most guardrails are not in compliance. Balusters or pickets are the vertical members which are installed between the rail posts. Generally, the balusters or pickets are installed into top and bottom rails. These can be installed using galvanized screws, ring-shank nails, or lag screws. In order for a new guardrail to be installed to meet current codes, the spacing between the balusters or pickets cannot be larger than 4”. The reason behind the 4” spacing for guardrails is that it will prevent a 4” sphere from passing between the balusters or pickets, which is less than the average size of a child’s head. There is also  a maximum variance which is allowed between the floor of the balcony and the bottom rail of the guardrail. This variance is not to exceed 4” just as the balusters or pickets. The reasoning for the spacing between the floor and the bottom rail is to prevent small pets or children from squeezing under the bottom rail. Note: The spacing may be less than 4”.


One of the most important functions of the guardrail is to prevent people from falling off a balcony or surface above 30” from the ground. In order for a guardrail to be fully functional, it must be capable of withstanding 200 pounds of force along the top of the railing in any direction. This is mainly attributed to how the guardrail posts are connected to the balcony. The best practice would be to attach the posts to the floor joist and header beam but some applications might suggest the 4×4 posts attach directly to the rim joist fascia of the balcony. This gives the user more access on the balcony, but usually the installation of posts to the face of the balcony will end up with dry rot forming between the post and the rim joist fascia.  The applicable force of the guardrail, the balusters or pickets, must  also be able to resist approximately 50 pounds of pressure applied to a square foot area. This can be done usually by installing the balusters or pickets from the inside of the balcony and fastened to the rails from the inside of the balcony. This would force any applied force to the baluster orpicket to be transferred to the top and bottom rail, and not the strength of the fastener holding it.

Guardrails are important to the life safety of residents within a community. It is highly recommended that guardrails are brought to current code if children are residing in the unit in which a guardrail has larger than 4” gaps between baluster or pickets, or have a gap of larger than 4” between the floor and the bottom rail. If you have a question about any balcony guardrails on your property, please give us a call and we would be happy to inspect your guardrails for you.