Load-bearing capacity of aluminum L-beam

[Derbyboy]

No, forget the insulation. I possibly mixed up the terms but this insulation is used in floating docks.

Start with 1,450 kg in total weight.

Sigh, you're making a mistake. Floating docks that have been in the water for a while weigh a lot, much more than they did when they were new. You will have to redo the construction if you calculate for 1400 kg.

 

[Derbyboy]

A 12-meter-long VKR 200x120x6.3 weighs 361 kg and costs approximately 16700 SEK according to the steel depot's price per kilo. It doesn't seem possible to purchase anything other than 12 meters in this case.

 

[Huggedugge1]

There is a good company that makes these kinds of decks. But due to our plot/patio, it was not possible to use them. However, I saw that they have now developed such a solution and I can guarantee that they do not use 200*100mm pipes. I even think it is aluminum.

Aqvisdeck.se
https://fb.watch/a-MbBrX1kB/
https://fb.watch/a-M0-ZTMSE/

 

[Bernieberg]

First, you need to know how much the construction actually weighs. The more exact the value, the easier it is to make the final construction.

Here, you need to know the weight of the material, how much extra weight it will absorb when it becomes wet (both the decking and the insulation), and any snow load it might be exposed to.

Then you can calculate how much different pipes (I imagine VKR/KKR) of that length can be expected to support.
Since you want the construction to be as light as possible, you would also want to go down to the smallest possible dimension, and then make sure to increase this by as much as the deflection of the load on the construction is.

It's also worth considering load cycles and the material's (steel's) aging because such a large span and wind movements will cause some sway in the structure.

However, my professional experience tells me that if you use a couple of VKR pipes (at least one on the long side that hangs, but preferably one in the middle as well) in the size 200x100x6.3, I would have them curved 5-8 mm in a smooth arc along the entire length.

Heavy? Yes, very much, but unfortunately, it's "what's required" for this type of span.

Edit: after seeing Derbyboy's post about a total weight of 5-6 tons (which I think sounds incredibly much), I would say if you want that length freely supported as it is today and with weight close to that, you have to increase further in material dimension.. 200x120x8 is probably the absolute minimum you need in that case. Guaranteed two pipes, and a deflection of 12-15 mm..

How do you pre-camber a VKR 200x100 10-15 mm in a nice parabola?

 

[Huggedugge1]

Where does the total weight come from?

Is it with snow?

Dry decking?

Nails and screws?

Then you also have to account for the weight of the pipes...

Edit: is the intention that you should be able to walk on the cover??

Yes, you should be able to walk on the pool deck. The weight is calculated based on the material specification. So add 20% or whatever you think. What material and dimension do I need?

 

[Violina]

How do you bend a VKR 200x100 10-15 mm into a nice parabola?

Bring out the gas welder

 

[Derbyboy]

There is a good company that makes these types of decks. But due to our plot/patio, we couldn't use them. However, I saw that they have now developed such a solution and I can guarantee that they don't use 200*100mm pipes. I even think it's aluminum.

Aqvisdeck.se
[link]
[link]

Yes, those roofs are really stylish and according to the brochure, they use aluminum. They also only weigh 20 Kg per m2.

 

[Huggedugge1]

Plus insulation and cladding... Got a comment earlier that it doesn't work with aluminum. Obviously, it does despite the same spans. Including snow load, wind, etc. etc.

I don't really care which, just want to know which material and dimensions solve my problem.

And since I can't do construction calculations and I'm not getting answers from suppliers, I humbly asked the question here. Is there anyone who can possibly give a correct answer?

 

[Violina]

Yes, those roofs are really stylish and according to the brochure they use aluminum. They also weigh only 20 Kg per m2.

Without decking..

With decking 40 kg per square meter..

But then they don't offer covers that roll along the short side with such a large span?

 

[richardtenggren]

The problem for you is the long span, a better design would have been to allow the deck to run along the long side. Then the construction would have been much sleeker, although this might not have been possible in your case. If you study the formula for deflection, you will see that the length is expressed in cubic, which means that the deflection is greatly affected by an increase in length.

I would also check the cellplast, it really looks like EPS and not XPS, as mentioned earlier it would be unfortunate to calculate on the wrong basis

If I had been given this task, I would probably have presented two solutions for the customer;

The first with sufficiently high profiles so that the construction could handle the free length even with a reasonable surface load (as I assume it will act as a deck when closed, exposed to snow, etc.).

The second option is to design the construction so that the deck handles its own weight, but in a closed position, the longitudinal beams receive support from the underlying structure. Thus, there would be one or more additional supports, and the short side's length needs to handle the load from people and snow.

For the surface load, it is probably enough to dimension for the snow load, as these rarely exist simultaneously, but someone in construction/architecture could probably answer that.

I guess the customer chose the second solution since it was probably much cheaper.

 

[Violina]

Plus insulation and cladding… Received some comments earlier that it doesn't work with aluminum. Obviously, it does despite the same spans. Including snow load, wind, etc.

I don't really care which, I just want to know which material and dimensions solve my problem.

And since I can't do structural calculations and I'm not getting answers from suppliers, I humbly asked the question here. Is there possibly someone who can give a correct answer?

Not if we don't know the weight of the construction.

Also, I doubt that the decking you linked to is walkable?

 

[Huggedugge1]

Without decking...

With decking 40 kg per square meter...

But then they don't offer covers that roll along the short side with such a large span?

but the films show exactly such a cover with my dimensions, i.e. 8*4 pool.

 

[Huggedugge1]

Not if we don't know the weight of the construction.

Also, I doubt that the deck you linked to is walkable?

Yes, it is. Legal requirement

 

[Violina]

but from the movies shows exactly such a cover with my dimensions, i.e., 8*4 pool.

Why didn't you buy from them then??

 

[Violina]

Yes, it does. Legal requirement

More than I knew.. But on the other hand, I will never get a pool either..