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Need Help Question How to Determine Pole Depth of Pre-Existing Pylon Sign

Discussion in 'Newbie Forum' started by Steven Ayvar, Sep 10, 2018.

  1. JTBoh

    JTBoh I sell signage and signage accessories.

    Jun 15, 2011
    Clermont, FL
    OP might check in city archives, which is time consuming and a pain in the a$$. The city will ALWAYS claim that "they can't find it", but it should exist somewhere. That somewhere is usually a box buried under decades of more boxes. Calculate that into your permitting time.

    PS - Get a shovel
  2. Marlene

    Marlene Major Contributor

    Jun 8, 2004
    good question, what do you use to get the actual square footage on odd shapes?
  3. Rick

    Rick Certified Enneadecagon Designer

    Apr 17, 2003
    Valle Vista

    Attached Files:

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  4. petrosgraphics

    petrosgraphics Member

    Feb 24, 2010
    cape cod, ma
    if this was a new store location for Arbies, the engineering was done by the the company that manufactured the sign. my experience has been, they ship everything as a complete kit. everything spec. out. it is more than likely a pour with rebar frame and possibly 1"-1.5" threaded rod for your anchor bolts. dig around the base to see how wide and how long the cement base is.
  5. Robin Canaday

    Robin Canaday Mythic Signs Portland - General Manager / Owner

    If I were you, I'd stick with a cabinet design that (once all the math was done) had the same load as the original cabinet. Then move onto more likely projects, if that was not acceptable to the customer. I hope you didn't promise them this cabinet :p.
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  6. Sandman

    Sandman Member

    Jul 2, 2005
    Crystal Falls, MI
    Robin nailed it. Reduce your sign design to match the size of the Arby's sign or pass on the job. I do my own engineering on these before handing it to the engineer for a stamp. First, I doubt if anyone is going to over engineer a base and pole structure very much beyond the wind load requirement for that area. Just one step up in pole thickness or diameter could add hundreds of dollars to the cost on a sign that size. Extra concrete would add even more. It just doesn't make sense that anyone would add hundreds and hundreds of dollars to the sign cost for no good reason. Wind loads are calculated on sign height, width, and square area. This will determine the pole diameter as well as the thickness of the steel. Then there is the base. Bases can vary widely in shape, depth, and footprint. Concrete bases can go straight down or flair outward toward the bottom. The twisting wind load on a single pole for a wider sign than the original is another consideration when figuring the structure. Putting a bigger sign than what was there before could be a disaster waiting to happen. You don't know what's underground but the first step would be to get the wall thickness of the steel poles and the height of each part and have an engineer do the calculations to see if the steel would even pass for a bigger sign. If it doesn't you don't even have to wonder what the foundations specs are.
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  7. Big Rice Field

    Big Rice Field Electrical/Architectural Sign Designer

    Area on odd shapes can be calculated using CAD software like "perimeter" in AutoCAD. But city planners like the simple rectangle method. Do not expect counter people to be math whizzes. They are usually the offspring of city officials.
  8. kcollinsdesign

    kcollinsdesign Member

    Apr 22, 2007
    Normal, Illinois
    Sandman nailed it! The quickest and easiest calculation you can make is determining whether the steel will support the new sign. In any case, in most municipalities you will need a stamped engineers drawing, but you can easily calculate this yourself with fairly good accuracy using the formulas in Peter Horsley's "Sign Structures and Foundations", which has been around for a long time. I find this is good enough for estimating, and when I get the job I'll pay the engineer to review my drawings. The engineer's job is simplified if I have already spec'd out the structure (he/she has to run fewer calculations if I have already done the design), and in most cases they can save you some material costs (value engineering). If you want to learn more about engineering sign structures, I would recommend Benjamin Jones' "Engineering Sign Structures" (not a light read, but if you have a basic understanding of trig and can work through some algebra it is not too difficult to understand).

    A more recent phenomenon is obtaining FAA clearances for structures over 20' that are within 20,000' (approx. 3.79 miles) of an airport runway, which will likely trigger a study in most cities ( https://oeaaa.faa.gov/oeaaa/external/portal.jsp ). You will need clearances for both your structure and to deploy your equipment. An even newer development is clearing radio frequencies used to communicate with remote signs. You will definitely want to clear those hurdles before you commit to a project. These studies don't cost anything (other than your time), but you may likely need them to get your permit (yes, I agree... does that mean I need an FAA study to put a ladder up to clean my gutters? Well, you don't need a permit for that, but I digress... ).

    And don't forget the crane operators certification ( https://www.signs.org/cranes ).

    Today's more savvy city planners and inspectors are requiring much more to get a permit than they used to. The old-school sign guys are getting run out of business. Some great opportunities here!
  9. spectrum maine

    spectrum maine Member

    Nov 1, 2012
    biddeford, maine
  10. kcollinsdesign

    kcollinsdesign Member

    Apr 22, 2007
    Normal, Illinois
    I calculated the surface area of the proposed sign to be approx. 33% more than the Arbys sign. Combine the increased area with a higher center of pressure and the ballast requirement will be significantly more than that required by the original sign. If you could decrease the area of the new sign to <150 sq. ft. and drop the overall height by around 5' you should be ok if the original base was designed correctly (I am not an engineer and I did these calculations quickly).

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