Clients pulling his own permit but is looking for engineered wind load calculations for a free standing d.f. 4 X 8 (vertical) but shouldnt make a difference.
Any ideas on where I might find standard wind loads for signs specifically?
Thanks!
Posted by goddinfla (Member # 1502) on :
A chart may not do you any good, most counties and cities require an engineer stamped drawing with wind load calculations.
Posted by Bob Stephens (Member # 858) on :
I figured that might be the case and thats what I told them. I know that some of the prefab monument signs give you the windload specs for their signs so I thought there might be some info somewhere on the internet.
In fact, Im sure there is just have to track it down.
Posted by jmathel (Member # 526) on :
Calculating wind load is not a "one size fits all" situation. The requirements for a windy coastal installation will be a lot different than a sign located between two buildings somewhere in downtown LA. The same is true for calculating the size of the footing. Sandy soil will not take the pressure that firm soil will.
I doubt you will find much on the internet but there is a good book on estimating wind loading and calculating footings, that is available from Signs of the Times. "Sign Structures and Foundations" by Peter B. Horsley. It won't make you an engineer, but it will help a lot in estimating structures and footings.
I believe their number is 1-800-925-1110
Posted by Bruce Bowers (Member # 892) on :
Bob,
I have to concur with Jerry on the Horsley book. It is a comprehesive guide to figure out just about anything that you ever wanted to know about building signs and associated structures.
It is worth every cent that it costs. I believe that it is available from the "Signs of the Times" magazine bookstore. It is available on-line.
Have a great one!
Posted by fontking1a (Member # 763) on :
Bob....How are hittin' em? Fairways and greens, fairways and greens.
Try jumping on www.ask.com. It's a pretty good search engine and more than likely you can find what you are looking for.
Talk to you soon.
Posted by Bob Stephens (Member # 858) on :
Thank you guys for the suggestions.
Lou I'm currently playing to a 4 handicap. Boy do I love this game. I've even retired from skydiving now to concentrate on improving my game.
Hope all is well. Lets catch up soon. Posted by Carl Wood (Member # 1223) on :
I thought the original post referred to a "Free Standing" vertical 4'x8' - just curious as to how this sign would be made - I had a request for the same type sign for a parking lot a coupla months back - I told 'em no way - if I can't put holes in the parking lot I couldn't install that sign. You're talking a LOT of wind load on that thing - twelve foot posts - kinda like a potato balanced on two toothpicks - I did the sign - double sided 4x8 vertical - mounted in dirt (they relented on the location).
Posted by Bob Stephens (Member # 858) on :
The sign is simply two 4x8 sheets of 3mm dibond structural aluminum back to back over 4"x4" 1/8" thick wall square aluminum post set in concrete.
I know the sign wont go anywhere even in hurricane force winds because I've built similar signs like this before.
My past experience with the windload calculations have always been over spec'd due to the potential for a hurricane.
Posted by David Harding (Member # 108) on :
Bob,
I ran an (unguaranteed) calculation and emailed it to you. I hope the format of the calculation makes sense. It is based on 30 PSF wind loading (valid in my area--but possibly too low for Florida). I do my own calculations for design and bidding purposes but have to get them checked and stamped by an engineer to be legal for permitting.
Four inch Aluminum square tubing with 1/8" wall (6063-T52 alloy) with 24" ground clearance will handle (barely) the stress with the called for 1.67 safety factor on the yield strength of the material. 12" diameter holes, 3-1/2' depth, filled with concrete, will provide the called for 2.5 safety factor on "fair soils".
Since the overturning resistance of the embedment goes up with the cube of the hole depth, a deeper hole is much more efficient than a wider hole from an engineering point of view, although the person DIGGING the hole may prefer the wider, shallower model (sounds almost like a Pontiac “longer, lower, wider” commercial).
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