IRC and IBC Code
Wednesday, 10 March 2010 18:18Last Updated on Tuesday, 29 June 2010 22:26
Written by Administrator
The following regulations are out of The International Building Code 2003 & The International Residential Code 2003 (translated into layman’s terms).
Guards- Where a fall hazard off of a deck, stairway, landing, ramp, etc. of 30″ or greater is present, then a guardrail is required.
Height Requirements: For single-family residences and for duplexes only, 36″ minimum guardrail height is required. The code says minimum, not maximum. So if the potential fall is only four feet down onto grass, the likelihood of a life-threatening injury is low. But if the fall is twenty feet down onto rocks, the threat is much larger. At that time it is wise to point out to the owner or contract the merits of possibly building a taller railing. As an example, in Canada 42″ is the minimum guardrail height for any construction.
All other multi-family, commercial and public works areas are required to have 42″ of guardrail protection. The one exception to this are guardrails contained within the inside of an R-2 individual dwelling unit. An example of this would be a 36″ high stair and overlook guardrail in a two-story townhouse unit, as part of a multi family building.
Openings: All locations that require guardrails must be constructed so 1) a 4″ sphere cannot pass through any opening in the guardrail within 34″ above finished floor (A.F.F) and 2) an 8″ sphere cannot pass through any opening in the guardrail from 34″ to 42″ A.F.F. We routinely see architectural drawings showing exact 4″ openings in various locations. This, by definition, does not meet code. As a result we routinely allow a maximum of 3-7/8″ in any opening, so we have a small margin of error. On a stair guardrail a 6″ sphere is the test, but only for the area forming a triangle between the tread, riser and bottom of the guard. Some uncommon exceptions to this rule are for loading docks, industrial areas and other non-public areas, where only three horizontal members are required for a guardrail, but still needs to be 42″ in height overall. Guardrail load (strength) requirements:
- Generally, guardrails are required to withstand a load of 50 pounds per lineal foot applied in any direction along the top rail. (Single-family and duplex guardrails do not have to meet this requirement. They are required to meet a 200 pound point-load test only). This load is not to be applied at the same times as other test loads. This means if you have a ten-foot long guardrail you would apply 50 pounds of load every foot, for ten feet, to achieve a total of 500 pounds. Single-family and private guardrails used to have to meet only 20 pound per lineal foot loading, but that requirement has been dropped with the IRC and IBC 2003 codes. There are some exceptions to this rule that apply to some I-3, F, H and S occupancies where the guardrail has to withstand only 20 pounds per lineal foot along the top rail.
- Guardrails shall be able to withstand a single concentrated load of 200 pounds applied in any direction at any point along the top rail. In testing, usually a one-foot square is used as a point load. This load is not to be applied at the same time as other test loads.
