Any one know the strength of 1" EMT (Conduit) ? Making homemade guard rails for Scaffolding

Photowhit

Okay, I'm cheap, follow me long enough and you'll find me picking up broken tie downs from the side of the highway for the hooks! Or lugging home broken cedar fence, or dehydrating 3 bushels of apples while they're cheap (Now...lol)

So, I have a fear/respect for heights. I'm getting around to finishing some solar projects and I'm too cheap to buy Scaffolding Guard rail set up, particularly since I can only setup one long side for most of the jobs.

http://www.homedepot.com/p/MetalTech-7-ft-x-5-ft-Scaffold-Tower-Guard-Rail-System-M-MG507K/206733478

This appears to just be lighter than 1" conduit, (16 gauge 1" OD tubes) So I've purchased a single 1" conduit (Conduit is 1" inside) and drilled (I know this weakens it) for mounting in the scaffolding tubes and drilled some 5/16th inch holes for Snap Pins and drilled out holes in some 2x4's as cross members/rails, at @18 inches and 32-36inches, I eye balled it. It's job is just to keep me from stepping off the scaffolding. but I'm guessing it would support 100lbs.

I can post some pictures if anyone would like, it sounds a bit confusing, but I'm using the conduit is posts and 2x4's as rails, sitting on the snap pins which are about 3 inchs long.  There are no spec's as to what the guard rail will hold, but I'd guess there is some OSHA guild lines...

Dave Angelini

The thickwall EMT I use 1.5", is very close to the snow load/wind spec of 1.5" water pipe which is generally specified for the ground mounts I use when I do not need tracking.
 I would not use the thin wall!  Hope this helps

softdown

Iron plumbers pipe may be the strongest pipe for the dollar? Just guessing...

I think grey PVC may be stronger, in some respects, than EMT.

jonr

My rough calculations suggest nowhere close to being stiff enough.  1.5" pipe looks minimally acceptable.

Photowhit

1 1/2" steel pipe is what the scaffolding is made of... It won't fit within the pipe.

I'm not trying to build scaffolding, I live near a nuke plant and have spoken to the fitters who build the massive multi story scaffolding from bare pipe and knuckles(?). I have scaffolding, just trying to figure out the strength of the guard rail I built.

I do think regular galvanized steel pipe would be plenty strong even with the drilled holes, to be a heavy load bearing structure, I'm sure I could hang on it. The only thing available is black pipe which would not fair well living outside.

It might surprise people that the braces for scaffolding have the same spec's as 3/4" conduit! ...but the max load is very minimal.

softdown

I've seen plumbers steel pipe, used in restaurants, to keep customers where they are supposed to be. With the tee's and accessories, you can easily build what you want. You may be able to slide thin wall pvc over it for weather-proofing...not sure.

BB.

Bracing may only be used in tension. And you can use cable and such too.

Only need larger diameter/thick wall piping if used in applications to resist bending.

If you put the railing under tension, then thin wall running/cable can be used.

If the railing would collapse from side loading, then thick wall pipe would be better.

-Bill "not a civil engineer" B.

softdown

Sometimes it is very hard to beat treated 2"x4"(s).

littleharbor2

How about running a length of rebar inside the conduit?

BB.

Pipe would be stronger per unit weight if you are looking at bending resistance.

-Bill

jonr

> 1 1/2" steel pipe is what the scaffolding is made of... It won't fit within the pipe.

So it might be possible to create a solid steel pin that connects the 1.5" scaffolding to a 1.5" post?  Or take what you have, set it a few feet above ground level and throw your weight at it.  I expect that how much a railing flexes is important to maintaining balance.

Photowhit

I'm good, it works fine, when researching the strength, I found a welding site where a guy made scaffolding out of 16 gauge square steel made me for more comfortable. I'm done with the needs for guard rails. I'll reset up on the short side tomorrow and will post a picture.  I might make some out of heavier gauge steel pipe later.

FWIW, I did think about inserting some 3/4" conduit inside to stiffen, but once I got my hands on the 1" I found it pretty strong/heavy (and lining up multiple holes would be a pain). I know the risk/weakest point is the holes drilled and tearing out. If I replace them I'll do a test. Mostly it's not intended to be load bearing, which I think the same goal as the company made hand rail. I do like having the 2x4 rail, set my drill on it several times.

Photowhit

Here are some photos of the guard rail, FWIW...

It's on the low end of the array, so I really don't need them.

mcgivor

You could always use sticks like they do in Laos.......just joking.  Have seen bamboo used in Hong Kong upwards of 30 stories, it's said they trust it over steel.

softdown

Bamboo is really strong. That would work fine for Photowhit.

Vic

Dave Angelini said:

The thickwall EMT I use 1.5", is very close to the snow load/wind spec of 1.5" water pipe which is generally specified for the ground mounts I use when I do not need tracking.
 I would not use the thin wall!  Hope this helps

Am a bit late to this,   BUT,  EMT IS EMT,  IMC IS IMC,  and RGD (Rigid) pipe IS RGD.   EMT is not threaded,  IMC and RGD pipe IS threaded,  as supplied in 10' lengths:

http://www.falsonsupply.com/Catalog/123FS.pdf

FWIW,   Vic

Dave Angelini

Definately but we can't always be as sharp as we want here. I did cover myself somewhat by saying the "thick wall" pipe is what you want for a mount. It is the same as schdule 40 water pipe which is often speced for ground mounting solar from my supplier Pro Solar.
I think bamboo would really be hard to spec in a 50 service life...

Photowhit

heck guy's the project's done and scaffolding down. My guess is that a 300lb guy falling 4 and a half feet against it would be retained on the scaffolding. I suspect I'll even replace it with heavier stuff, likely ridged pipe (RGD I've learned) and test the conduit for you at some later date.

Dave Angelini

Did you need any bamboo?

Photowhit

No I managed without. Maybe when I'm home for Turkey day in Florida. Seriously it's great stuff and resilient. Likely a better choice than a 2x4 for rails...

...though setting a drill on it will take some talent!

mcgivor

Some pretty good videos on YouTube show how they build  bamboo  scaffolding, no drilling required.