Quick answer
Pole, pylon and monument signs almost always need sealed structural calculations for wind loads and the foundation, and large wall signs often need an engineered attachment to the building. Sign permits usually involve zoning approval for size and placement, a building permit for the structure, and an electrical permit for illuminated signs.
Signs are tall, flat and exposed, which makes wind the controlling design load. A sign that looks simple can carry a large overturning force at its base.
Which signs need engineering
- Pole and pylon signs: the pole or columns, connections and the embedded or spread foundation
- Monument signs: the foundation and any masonry or framing
- Wall signs and channel letters: attachment to the wall, especially on large signs or weak wall systems
- Projecting and blade signs: brackets and anchorage that resist wind and their own weight
- Rooftop signs: supports and the roof structure beneath
What the engineer designs
- Wind loads for the sign size, height and site exposure
- Pole or column size and the connection of the cabinet to the structure
- Footing diameter and depth, based on soil properties
- Anchors and fasteners into the building for wall signs
Three approvals, usually
- Zoning: maximum size, height, setbacks and number of signs
- Building: structural calculations and drawings
- Electrical: for illuminated signs, typically with a listed sign assembly
In shopping centers, the landlord’s sign criteria apply too.
Sign companies
We support sign fabricators and installers with fast, repeatable structural calculations for pylon, monument and wall signs across many states. See engineering for contractors.
What to send us
- Sign drawing with dimensions, height and weight
- Site address (for wind speed and exposure)
- Wall construction for wall signs, or soil information for pole signs if available
Common questions
Do I need an engineer for a monument sign?
Usually yes, for the foundation and wind design, especially for taller or larger signs.
How deep does a sign pole footing need to be?
It depends on the sign size, height, wind speed and soil. The engineer calculates it; deep embedment is common for tall pylon signs.
Does a replacement sign face need a permit?
Swapping a face in an existing cabinet often needs only a minor permit or none. New or larger signs need full review.
Can one calculation cover several identical signs?
Often, if site conditions and wind speeds match. Each site still needs its own permit.