4'x8' 3/4" Swinging MDO sign question.

[SW101]

Hey Fellas,

I had a customer call me a few weeks ago specifically wanting a 4'x8' wooden sign to replace his current 4'x8' wooden sign that had broken in half after being up for 13 years.
So I finished the sign and he decided he wanted me to install it (originally he said he would install it). I mounted 3 stainless hanging tabs across the top, delivered the sign and installed it.

The frame was a very solid wooden frame made of rounded boards all the way around the sign that have the same look as your common fence post. The sign sets about 4ft off of the ground.

After installing the sign I realized how windy the area was and how much wind the sign is going to catch on a daily basis. I would have advised them to do a solid mount sign had they not already had their existing structure. Also, this is a small mom and pop business that doesn't have the money to spend on creating a whole new structure to mount the sign a different way. I feel like more needs to be done to ensure this sign gets 13 plus years as well.

My question is, would it put more stress on the sign to swing everyday or would there be more stress put on it to have solid mounting tabs coming in from the sides and bottom? I thought about mounting hanging tabs on the bottom of the sign and tying them to the board that runs across the bottom, but then I was afraid that would place more stress on the sign then letting it swing freely, so I'm not sure what the best route to go would be here. Also, we are talking about 10-15 mile an hour winds in WV... FYI. Any suggestions are greatly appreciated!

 

[TimToad]

There is no way any of us could speculate on what the uprights going into the ground in were set with, how deep they were dug, whether they were properly sealed, or if they were pressure treated, etc... Nor how the thing is joined together.

At least you don't get tornadoes there......... LOL

You're asking total strangers who haven't got a clue to the structural integrity of a 13+ year old wood frame for structural engineering advice.

Hate to be blunt about it, but you'll have to trust your own judgement on this one. Does it walk a like a duck? Does it quack like a duck?

In other words, did it feel good and solid when you gave it a decent tug? Are the uprights showing any sign of rot or weakness when you lean on them a bit? Some of this stuff is simple common sense.

I understand the bit about a mom and pop operation, but they milked the first sign for 13 years. Let's just say the whole sign, frame and all cost them $1,000 13 years ago. That means they only paid about $6.50 per MONTH for their primary site signage. For the cost of a couple of beers per month, they could get another brand new sign and frame.

 

[Rick]

I agree with Tim....

My opinion is, a swinging 4 x 8 is a scary idea, better to make sure the structure and panel are solid.

I get that they have no money, but by you installing it, does that make you responsible for it?

If there was any doubt of the structural integrity, you should have passed.

My opinion is, 15-20 miles is no big deal. A 95 mph gust will send that 4 x 8 sailing like a circular
saw if you let it swing, or the whole sign structure will just plop right over if it's attached solid... just
depends on the weight. What is the required structural wind-load in your area?

I have seen guys pour a spread footing and attach the existing post to it. I've also seen guys dig up one
side of the post to see how deep it went, I think it's a better idea to get a fresh structure. either way,
have the client sign off that they are responsible or they acknowledge that the post can handle the required
wind-load standard.

 

[CanuckSigns]

Can you post a pic?

 

[OldPaint]

seems to me the last sign lasted 13 years..........AND THE SIGN broke in half, NOT THE FRAME/SUPPORT STRUCTURE!!!!
the original was a SWINGING SIGN......and didnt get blowed away in 13 years..........putting the same thing back seems like a no brainer. if it aint broke....dont fix it)))))))
just for you math people........a swinging sign of 32 sq ft.........weight will increase slightly with a say 20-30 mph wind. that same 32 sq ft sign bolted solid and taking direct 90 degrees wind......it put more pressure on exiting mountings....because it it is not able to deflect the wind)))))) as a swinging sign would....................

 

[jaylem]

air release

a swinging sign mostly definatley puts less stress on the entire structure than a rigid mounted face. The swinging action acts as a release. Kind of like sailing. When the sail is tight an incredible amount of force is captured and propels the boat in a direction. When a sail is flapping in the wind very little force is captured and the boat will have little movement. Or, in sign terms. The swinging action is like air reliefs in a banner.

 

[Rick]

The force of a swinging 4' x 8' panel is only as strong as the hardware is holding it.
Is the hardware holing it going to be as strong as the 2 posts?

If the hardware is equal too or less than the structure... that served it purpose for 13
years, it's safe to assume a rigid mount is preferable.

Seems to me by only allowing the top part of the post to bear all the weight it could add
more stress to the lower portion of the post. Having an equal amount for stress throughout
the post might be better with constant low velocity winds.

For the life of me, I've never seen a ground mounted swinging 80 lb+ 4' x 8' MDO panel... and to do
it because you think the supporting structure might not handle a rigid mount? A little crazy...

 

[GAC05]

seems to me the last sign lasted 13 years..........AND THE SIGN broke in half, NOT THE FRAME/SUPPORT STRUCTURE!!!!
the original was a SWINGING SIGN......and didnt get blowed away in 13 years..........putting the same thing back seems like a no brainer. if it aint broke....dont fix it)))))))
just for you math people........a swinging sign of 32 sq ft.........weight will increase slightly with a say 20-30 mph wind. that same 32 sq ft sign bolted solid and taking direct 90 degrees wind......it put more pressure on exiting mountings....because it it is not able to deflect the wind)))))) as a swinging sign would....................

OP, 13 years ago there was no global warming......................

wayne k
guam usa

 

[visual800]

I wish you folks would start posting pics of items like this so we can see the sign or at least the frame.

As far as all of this being wood I would personally tear it all out and replace it with aluminum framing skinned with aluminum faces and attached at bottom also. lightweight and durable. all wood is alot of weight on something like that PLUS the wood you would use now if probably crap compared to what was originally used

 

[OldPaint]

OP, 13 years ago there was no global warming......................

wayne k
guam usa

really.........but then...........look where you live..........its the same there EVERYDAY.......even 13 years ago))))

 

[Billct2]

Seriously, without seeing this frame in person there is no way to give an accurate response.
That being said a swinging sign should swing ,a fixed sign should be fixed.
If I make a swinging sign I try to make them heaver rather than lighter.

 

[rjssigns]

In my neck of the woods we figure anything rigidly mounted at 30 pounds per square foot wind loading. 4' x8' comes to 960 pounds working on the structure.

 

[SW101]

Thanks for the opinions fellas. For the record the structure holding the sign is very solid, solid enough that it would easily handle a swinging sign or a solid mount. I would not have installed it on a structure I didn't think could handle the sign. It was the sign itself I was debating whether stress points would be greater if it were mounted as a swinging sign or stationary in the given structure. But again, the structure that the sign is hanging in is not of question to me.