Load-bearing capacity of aluminum L-beam

[AXS]

Now there were many pages in the thread, maybe I missed something.

But I think the entire joist should be oriented the other way. So cc60 on 8 meters. Ideally, you need to get up to joists at 300mm height, but with slightly increased deflection, you could probably go lower. Especially if you have some joists reinforced with steel, I would have chosen an L-profile as they are easy to obtain.

 

[Erik Lindroos]

Beam options:

VKR 200x100x8. Quite heavy (35.1 kg per meter, 9 meters become 316 kg). According to Stena steel, 9 meters costs around 15 kkr. According to @Violina, it can be cambered relatively easily (although it should of course be done by someone with a bit of experience).

IPE 200: The most weight-efficient shape (22.4 kg/m, 9 m weighs 202 kg). Stena's price for 9 meters is approximately 9 kkr. According to @Violina, somewhat trickier to camber.

Custom-built à la @Bernieberg. Not sure what it would cost, but a neat solution if it works.

Stainless steel, expect 8-10 times higher price.

Regular versus cambered/precambered. Difficult for me to say in terms of price, but cambered is advantageous in more ways. Avoiding deflection there provides a bit more margin for the wooden beams to flex. Because they will flex a bit.

Additional: If 200 mm height doesn't work, you can choose HEA 180. As heavy as VKR (35.5 kg/m) but stronger (less deflection).

 

[Stefan1972]

Even though I still don't understand why there's such a focus on thick beams... Have you looked at my simple suggestion earlier in the thread? Stainless steel sheet, maybe 3mm thick, as high as the side and bent with a fold on the underside. Four such pieces welded together to make the full length, and then everything screwed into the wood fairly tightly. It probably won't flex much if well mounted. The only thing visible then is a shiny side, and you don't need to modify anything or buy expensive beams.

 

[Erik Lindroos]

But I still don't understand why people are so fixated on heavy beams...

Quite simply because it seems to be required when you calculate it.

 

[Huggedugge1]

Honestly..

I could easily create this construction without a bunch of "fancy" calculations, simply because I have so much experience with this type of constructions..

But trying to give someone a solution online that yields the desired result, when the own attempt resulted in what is seen in this thread, I find quite difficult..

@Huggedugge1 I'm tired of reading more in this thread.. But once you have come to the solution you have in mind and have a reasonable production plan, feel free to contact me so I can take a look at it..

Then I will give you my honest opinion on how difficult it actually is to manufacture it in a way that you get a construction that is both durable and fulfills the desired function..

Because as someone who has experience from "both sides," meaning both as a designer and as the one who manufactures what someone else has drawn, I know how little they often understand about how things actually behave in reality..

I have no reason to doubt anyone's competence. Obviously, it's more difficult than I understood. I don't have your expertise which is why I have humbly asked for help here.

I'm not sure what information you felt was missing?

But now a suggestion has come up that I think is good and realistic. Which I understand you don't believe in? I can't assess it so if you have any objections, you are welcome to express them.

 

[Huggedugge1]

But I still don't understand why people are so fixated on using large beams... Have you looked at my simple suggestion early in the thread? Stainless steel plate, maybe 3mm thick, as high as the side and bent with a fold on the underside. Four such pieces that are welded together to get full length and then everything is screwed into the wood quite closely. It probably won't flex much when properly mounted. The only thing visible then is a shiny end plate and you don't need to modify anything or buy expensive beams.

From what I understand, beams are required according to what has been calculated.

 

[Violina]

But I still don't understand why there is such a focus on heavy beams..........Have you looked at my simple suggestion early in the thread? Stainless steel sheet, maybe 3mm thick. Just as high as the side and bent with a fold on the underside. Four such pieces welded together to get full length and everything is screwed into the wood quite densely. It probably won't sag much when properly installed. All that is visible then is a shiny end and you don't need to modify anything or buy expensive beams.

Well.. that's the thing..

You simply DON'T UNDERSTAND the problems with this type of construction with such a span (which the original poster also didn't understand before trying to build and ending up with a construction that doesn't work)

8+ meters in span is nothing "to play with"

 

[Violina]

I have no reason to distrust anyone's competence. Obviously, it's more difficult than I understood. I don't have your competence, which is why I have humbly asked for help here.

I'm not really sure what information you were missing?

But now a proposal has come that I think is good and realistic. Which I perceive you don't believe in? I can't assess it, so if you have any objections, you are welcome to make them.

Either YOU need to decide on the construction you want to go for, or you need to ask someone else to do it.

After that, you need to make sure to produce documentation for manufacturing it so that the total weight (keep in mind that moisture in the timber and snow on the "roof" is added) is clear.

It's very difficult to give sensible advice when you don't provide the exact conditions that apply.

Honestly, I think the best thing is if you buy the ready-made deck for your pool; in the end, it will likely be the cheapest solution, because the risk is that this construction will be under-dimensioned or incorrectly made and then simply will not withstand the loads it is exposed to.

 

[Stefan1972]

From what I understand, beams are required according to what they have calculated.

Yes, but theory and practice can differ significantly. You have noted yourself that a beam becomes enormous if it is not supposed to deflect at that length. Today, you have a frame construction in wood that deflects a little. It probably doesn't need massive reinforcement to become acceptable. Calculating all conceivable loads becomes strange because even if there is a little snow sometimes, it's not going to collapse, and you can shovel regularly to keep extreme loads in check. But sure, if you're going to park the car there, it obviously needs to be strong.

A metal sheet with a bit of height and a fold, then screwed tightly, becomes incredibly stiff as long as it's secured and doesn't allow bending/creasing. Building with a beam means the construction is bulky in itself just because it has a beam and that span. It will end up resembling some bow door on a ship at last.....

 

[Derbyboy]

Beam options:

VKR 200x100x8. Weighs quite a lot (35.1 kg per meter, 9 meters will be 316 kg). According to Stena Steel, 9 meters cost around 15 kkr. According to @Violina, it can be cambered relatively easily (although, of course, it should be done by someone with a bit of experience).

IPE 200: The most weight-efficient shape (22.4 kg/m, 9 m weighs 202 kg). Stena's price for 9 meters is approximately 9 kkr. According to @Violina, somewhat trickier to camber.

Custom-built à la @Bernieberg. Do not know what it would cost, but a nice solution if it works.

Stainless steel, expect 8-10 times higher price.

Regular versus cambered/pre-bent. Hard for me to say in terms of price, but cambered is advantageous in more ways. If you avoid sagging there, it gives a bit more margin for the wooden beams to deflect. Because they will deflect a bit.

Additionally: If it doesn't work with 200 mm in height, you can choose HEA 180. Heavy as VKR (35.5 kg/m) but stronger (less deflection).

The original poster has stated in post 34 that an HEA that is 250mm high is required.

 

[Stefan1972]

Nah.. that's the thing..

You simply do not UNDERSTAND the issues with these kinds of constructions with such a span (which the ts also didn't understand before he tried to build and got a construction that doesn't work)

8+ meters in span is not "to be played with"

I have built enough to understand the thing..........Also worked with heavy steel. We still have a given scenario with a built wooden structure that can be reinforced slightly to achieve the desired result. If you want a bending-resistant construction in beams, then it's a completely different thing. Then you have to take the self-weight of the beam into account as well, plus everything else. Then, of course, it becomes a sturdy construction but completely unnecessarily.

 

[Erik Lindroos]

TS has stated in post 34 that an HEA that is 250mm high is required.

Of course, I could be wrong somewhere, but my tables indicate a higher moment of inertia for HEA180 (2510 cm^4) than for the VKR 200X100X8 (2269 cm^4) that was calculated earlier in the thread. Then TS also wrote in post #34 that
"But honestly, it doesn't feel like any suppliers are completely sure what the stiffness will be. They're good at selling."

 

[Huggedugge1]

No.. that's the thing..

You simply DON'T UNDERSTAND the problems with this type of constructions with such a span (which the OP also didn't understand before he tried building and got a construction that doesn't work)

8+ meters in span is nothing "to play with"

But… It's an unusual application, but as you saw in the video, it works in aluminum for the same pool I have. But not according to you. From what I've understood, you've never designed or built such a solution. But you refer to your broad competence and long experience so that you didn't need to calculate anything but just go "freehand." Several other people have helped with calculations, and in terms of calculations, most seem to agree on dimensions. It all came together in a solution that I perceive as good and looks nice.

I can't assess it any other way, and now it feels like the proposal with an overlaid T-beam is best. Replace the framework with 170 and maybe reinforce with 3 mm stainless steel in the dimensions 170*45 on every other beam which we place CC 45 cm with some noggings.

I am humbly grateful for all the help I've received from everyone!

 

[Huggedugge1]

Of course, I could be wrong somewhere, but my tables indicate a higher moment of inertia for HEA180 (2510 cm^4) than for the VKR 200X100X8 (2269 cm^4) that was previously calculated in the thread. Then the OP also wrote in post #34 that
"But honestly, it doesn't feel like any suppliers are entirely sure about what the stiffness will be. They are good at selling."

We had a welder here from a company. He had an app and entered a lot of variables and said that I needed an HEA 250. He himself thought it was clumsy and said there should be more elegant solutions.

 

[Derbyboy]

Well... It's an unusual application, but as you saw in the film, it works in aluminum for the same pool that I have. But not according to you. From what I understand, you have never designed or built such a solution. But you refer to your broad competence and long experience so that you didn't need to calculate anything but just go "freehand." Several other people have helped with calculations and calculation-wise, most seem to agree on dimensions. Everything fell into a solution that I perceive as good and will be nice.

I can't assess it in any other way, and now it feels like the proposal with an overlaid T-beam is best. Replace the framework to 170 and maybe reinforce with 3 mm stainless steel in the dimensions 170*45 on every other joist that we set CC 45 cm with some blocking.

I am humbly grateful for all the help I've received from everyone!

a clarification...

If you use three bearing beams (span of 220cm between the beams) in your construction, you can manage with 45x170 on the joists.

If you use two bearing beams (span of 440cm between the beams) in your construction, you ABSOLUTELY CANNOT manage with 45x170 on the joists.