Decks

Call Before Digging

Contact Joint Utility Locating Information for Excavators (JULIE) at 811 prior to digging post holes.

Inspections are required for post holes, rough, and final. For more information, call the Building Department at (847) 223-8515 Monday through Friday, 8 a.m. to 5 p.m.

Permit Application Requirements

  • Completed building permit application
  • Provide one (1) copy of plat of survey dimensionally locating deck with regards to property lines and any buildings
  • Provide two (2) copies of pier and framing plans indicating dimensions and materials (with sizes) to be used in construction

Maximum Deck Joist Spans

Southern Pine

Joist Size 
12-inch O.C.
16-inch O.C.16-inch O.C.
2 by 813 feet -  1 inch11 feet - 10 inch
9 feet - 8 inches
2 by 1016 feet - 2 inches
14 feet - 0 inches
11 feet - 5 inches
2 by 1218 feet - 0 inches
16 feet - 6 inches
13 feet - 6 inches

Douglas Fir-Larch, Hemplock-Fir, SPF

Joist Size
12-inch O.C.
16-inch O.C.
16-inch O.C.
2 by 812 feet - 1 inch11 feet - 1 inches
9 feet - 1 inch
2 by 1015 feet - 8 inches
13 feet - 7 inches
11 feet - 1 inch
2 by 1218 feet - 0 inches
15 feet - 9 inches
12 feet - 10 inches

Redwood, Western Cedars, Ponderosa Pine, Red Pine

Joist Size
12-inch O.C.
16-inch O.C.
16-inch O.C.
2 by 811 feet - 8 inches
10 feet - 7 inches
8 feet - 8 inches
2 by 1014 feet - 11 inches
13feet - 0 inches
10 feet - 7 inches
2 by 1217 feet - 5 inches
15 feet - 1 inch
12 feet - 4 inches

Handrails and Guardrails

Porches, balconies, or raised floor surfaces located more than 30 inches above the floor or grade below shall have guardrails not less than 36 inches in height.

Open sides of stairs with a total rise of more than 30 inches above the floor or grade below shall have guardrails not less than 34 inches in height measured vertically from the nosing of the treads.

Required guardrails on open sides of stairways, raised floor areas, balconies, and porches shall have intermediate rails or ornamental closures which will not allow passage of an object four inches or more in diameter. Horizontal spacing between the vertical members in required guardrails shall be a maximum of four inches at the nearest point between the members.

(This is information only and does not contain all requirements for construction).

Notes:

  • All structural lumber, beams, wood deck flooring, and other appurtenances shall be constructed of lumber that is preservative-treated.
  • Framing and fasteners/connections shall comply with the International Residential Code/2009.
  • Piers shall be a minimum of eight (8) inches in diameter of poured concrete, with level bottom, forty two (42) inches below grade, framed up a minimum four (4) inches above finished grade.
  • 5/4 inch by 6 inch deck boards should not span more than 16".
  • Cantilever shall not extend more than two (2) feet with a ratio three (3) feet in to one (1) foot out.