Suppose’n I wanted to use 4” schedule 40 PVC as a stand, meaning I’d cut it in to a 4” section and stood it upright, how much weight would it support? Can it hold 400lbs?

What about schedule 80 pvc?

Look up pvc jet ski stands. Most you see are supporting in similar weight and that is lengthwise.

I'm not an expert, but I believe the tensile strength on 4" schedule 40 is over 4000lbs. I'm not sure how that relates to compressive strength, but I'd bet 400lbs is no big deal.

You mean like a deer stand? 10 feet or so above ground? Sch40 will get what you want, but I don’t know that I’d feel all warm and fuzzy about it….plus unless you paint it UV is a pvc killer….

Just like sizing a post for a deck it depends on the height.
I’d assume that if you’re talking about 2 or 3 feet probably but if you’re talking about 15 or 20’ not so much…

It'll support a lot more weight if you pour it full of concrete. Makes a great post for the mailbox.

I used 3" pvc, 3 pieces about 3" long under the water heater so it didn't sit directly on the concrete floor.
A 50 gallon water heater full of water has to be around that weight.

In this instance, it would be 4" tall, 4" diameter, supporting +/- 400lbs, I cannot fill it with concrete. It would be interior, so I'm assuming UV degradation isnt a problem.

quote:

Originally posted by MikeGLI:
In this instance, it would be 4" tall, 4" diameter, supporting +/- 400lbs, I cannot fill it with concrete. It would be interior, so I'm assuming UV degradation isnt a problem.

4" will not be any sort of problem. You could use much smaller dia & not have an issue, the vertical load bearing isn't even worth looking up.
The only issue I could possibly see is how you are supporting/balancing whatever load you have - I'd bet it's bigger than 4" dia, so balance & attachment will come in to play. 4" is not a big deal no matter what, but PVC doesn't have great lateral strength - it will bend & then fail if the load isn't balanced.

Strength of materials is one thing. Whether it will work in a particular design is another. Whether a structure will support a given weight depends on the details (geometry, e.g.)

In other words, just knowing XYZ material is being used will not tell you whether a given structure will fail. You could build a bridge using wood and have it stand, or a bridge out of steel and see it collapse.

Some things are strong in compression and fail quickly under tension. I think PVC pipe probably fits into that category - a long stretch of unsupported PVC pipe would not be hard to crack with sufficient load in the center of the unsupported span.

In other words....need more details.

A sketch, maybe?

I dont have a sketch. Assume a totem pole, varying in height from 5' - 7'. This PVC will operate as the base for the totem poles, or a spacer if you will. PVC sits on floor and totem poles on PVC. Max weight is around 400lbs.

I suppose the alternative is steel.

That should be no problem. Hockey pucks might do the trick as well.

quote:

Originally posted by rsbolo:
That should be no problem. Hockey pucks might do the trick as well.

I need the material to be hollow as it's overlaying a 3" steel pipe.

From strength and materials classes many moons ago:

Cross sectional area of schedule 40 PVC pipe = 3.12 in2.

Compressive strength PVC = about 8000 psi

8000 psi/3.12 in2 = 2564 pounds to compression failure. 400 pounds good to go.