2012 International Residential Code for One- and Two-Family Dwellings (IRC)
International Code Council / 01-May-2011 / 935 pages
This comprehensive code compiles all building, plumbing, mechanical, fuel gas and electrical requirements for one- and two-family dwellings in one convenient code. The regulations cover dwellings and townhouses up to three stories. Now in its fifth edition, the IRC contains many important changes including:
- A new wind map delineates areas requiring design to resist wind forces.
- A new map identifies windborne debris regions.
- The minimum clearances to lot lines have been reduced from 5 feet to 3 feet for unrated exterior walls when the dwelling is protected with a fire sprinkler system.
- The IRC now permits construction of unrated exterior walls on the lot line when all dwellings in the subdivision are protected with automatic fire sprinkler systems and the opposing lot maintains a minimum 6-foot clearance from the common lot line. Attached garages using this provision also require sprinkler protection.
- Doors between the garage and dwelling unit now require self-closing devices.
- Wireless smoke alarms are now specifically permitted for satisfying the interconnection requirements in both new and existing dwelling units.
- The provisions for roof connections to resist wind uplift forces have been updated and simplified. A new table provides prescriptive values for both low and high slope roofs in wind exposure categories B and C.
- When a parapet is not installed, openings and penetrations of the roof are no longer permitted within 4 feet of the separating wall between townhouse dwelling units.
- The IRC now includes prescriptive provisions for the construction of isolated masonry pier foundations supporting raised floor systems.
- Installation of 1/2-inch gypsum board or equivalent is now required on the underside of floor assemblies of cold-formed steel framing, I-joists, open web trusses and similar light-frame members.
- The IRC Wall Bracing provisions have been completely reorganized to place each topic in a separate section and improve the flow of information.
- New simplified wall bracing provisions offer an alternative method of bracing in low seismic regions with basic wind speeds of 90 mph and exposure category A or B.