Weld strenght

[anr164]

Hey everybody, writing to you from Sweden I wonder if you could please help me.
I will begin by posting some three pictures so you can understand me easier.

http://postimage.org/image/2fh2e3smc/

In that picture it seems like the cabinet (?) is "flyging" meaning it does not touch the floor. That is what I want to do, but first two other pictures from UNDER.

http://postimage.org/image/2fhm8jyjo/

http://postimage.org/image/2fib1m5yc/

Now, I want to do the same, BUT, my cabinets, and my steel bars I want to withstand the weight of 300Kg (600lbs).

Is this possible, or should i stop dreaming? Please help me..
You might just get rewarded But pleeeeeeease help!

 

[dhengr]

Anr164:
You are cantilevering the vanity top off of the wall behind it. 600lbs. is three pretty large people, do you really mean that? It can be done, but the size and strength of the cantilevered structure (the steel tube structure you see) is directly proportional the weight supported. And, the wall that is supporting this whole vanity must be stronger in the same proportion. Can the marble counter top actually take those kinds of loads, and over what areas and span lengths?

You should define the load better. At the moment I’d say you have 600lbs. on a ~24" cantilever, and this is actually carried by several members, maybe spaced at the same spacing as the studs in your wall behind. We may have to strengthen the studs to take this. The front steel tube is required to support the front edge of the marble top and tie the cantilever tubes together. You should know more about the strength of your counter top material (I said marble) because that will determine the tube spacing to support it. Then this entire structural steel system must work around the sinks you are using.

 

[anr164]

dhenrg
Thank you for replying.
Yes i mean 600lbs (300kg). The steel tubes are supposed to be 40x40mm with a thickness of 4mm.
They reach out 570mm and the backer metal plate is 10mm thick.
I dont want to put a vanity top on the bars, I want to put a whole cabinet. And that cabinet with all content etc has a total weight of 300kg (600lbs). I can post a new picture too with a structure that may be better suited for this task.

 

[flash3780]

My biggest concern would be the connection to the wall. I assume that you're attaching it to wooden studs? You'll have a pretty large moment with a 600 lb load (that's 1/5 of a compact car). It's definitely a good idea to spread things out - the picture that you attached is certainly an improvement.

I would look at the loading on the bolts to determine whether or not your design is adequate to hold that much weight.

As was mentioned above, the distribution of the loading on the countertop is also a concern. You don't want to crack your marble countertop.

 

[dhengr]

Anr164:
Do you understand the engineering concept (actually a statics concept, in the case) of loads, lever arms and moments? Google it. Your last picture would work just fine, but it still seems that might be the hard way. Tell me more about the construction of this cabinet which is already designed to carry 600lbs., it may be strong enough to allow another support system. Also, Google ‘french cleat.’

Why not put a shelf angle on the wall at the bottom of the cabinet, it’s loaded primarily in shear at the wall, rest the cabinet on that angle and tie the cabinet back to the wall at the top of the cabinet. Assuming the cabinet will take either of the above, they are much more structurally favorable, and less expensive ways to skin this cat. Of course, the wall must be able to take this overturning moment too.

Talk with your favorite Structural Engineer on this problem, he/she will explain this and be able to see the existing conditions, and size what you need, much quicker than I can type back and forth.

 

[anr164]

flash3780
We dont need to worry about the connection to the wall since Im using Hilti bolts made to resist the weight of 1600kg fastened to a concrete wall (20/25).
You also need to know that the 600lbs of weight will NOT be on the top of the countertop but distributed since what I want is to build a kitchencabinet and put a granite countertop on top and that the steel structure must bare the total weight of 600lbs, that is, it will never be 600lbs on the countertop.

Dhengr
What do you mean with "the hard way"?
Yes I thought about alternatives but this is the way that will be the least "showable"...
I'll make a new sketch with more info on the cabinet etc...

 

[anr164]

adding two new pics with more info

 

[anr164]

pic1