• The sign configurations listed here require building plan review. They also require structural calculations where indicated. The building plans reviewer may determine that structural calculations are required on sign configurations other than those listed. Structural calculations, details and drawings must be stamped and signed by a civil/structural engineer licensed by the state of Washington.

    Free-standing Signs

    • Signs with a height greater than five feet that are constructed entirely of concrete or masonry. Structural calculations are required for signs with a height greater than eight feet.
    • Signs constructed of materials other than concrete or masonry with a height greater than eight feet. Structural calculations are required.

    Face-mounted Signs

    • Face-mounted signs with an area greater than 100 square feet or weighing more than 750 lbs. Signs must be connected to the building structure with fasteners at 48 inches on center, maximum, around the perimeter of the sign. Alternatively, provide structural calculations for determination of fastener size and fastener spacing.
    • Structural calculations are required for face-mounted signs with an area greater than 200 square feet or weighing more than 2,000 lbs.

    Projecting Signs

    • Projecting signs with an area greater than 30 square feet or weighing more than 250 lbs.
    • Structural calculations are required for projecting signs with an area greater than 50 square feet or weighing more than 400 lbs.

    Awning or Canopy Signs

    • All awning and canopy signs require review.
    • Structural calculations are required if the height of the sign is greater than four feet.

    Signs Mounted at or Above the Roof

    • All signs mounted at or above the roof level require review.
    • Structural calculations are required.

    Design Criteria

    Based on provisions of the 2018 International Building Code.

    • Gravity loads - self-weight and applicable live loads as required by IBC Chapter 16.
    • Wind Design Criteria (Section 1609) - 1Basic Design Wind Speed 98 mph, Exposure (site specific)
    • Seismic Design Criteria (Section 1613) – Class Site D-default (unless otherwise specified by a geotechnical engineer).
    • Design for Combined Loading - as specified in Section 1605, Load Combinations.

    Structural Requirements

    The following structural information is required with your permit submittal:

    • Dimensions of the sign and structural supports.
    • Elevation of the sign above grade and with respect to the roof.
    • Weight of the sign (including frames, etc.).
    • All materials and material grades of structural members and connections.
    • Cross sections showing structural members and fastening methods.
    • Existing building support structure (i.e., the building structure that is supporting the sign).
    • Size, spacing and quantity of all fasteners (lag bolts, nails, welds, etc.).
    • All structural components of the sign itself (including dimensions, materials, etc.).

    Definitions

    Free-standing Sign – a sign supported directly by a foundation. Examples include a monument sign (wall sign) and a pole sign (vertical “flag pole” sign).
    Free standing sign height is measured from the lowest adjacent finished grade to the top of the sign.

    Face-mounted Sign - a sign supported by the building structure and projecting less than one foot from the face of the building.

    Monument Sign – a wall sign supported directly by a foundation.

    Pole Sign – a vertical pole sign (“flag pole” sign) supported directly by a foundation.

    Projecting Sign – (blade signs, hanging signs, etc.). A sign supported by the building structure and projecting more than one foot from the face of the building.

    Awning/Canopy Sign – a sign imprinted on or attached to an awning or canopy. Note: an awning or canopy without a sign requires a building (BW) permit rather than a sign permit.