The most sustainable glue for wood?

[roli]

It should then withstand 15 tons of snow load.

Again, you're throwing out information that you don't have a clue about. Like above, a roof should withstand 15 tons of snow load…???…
Where do you get that from??? There are standards that dictate how to calculate, and where the roof's geographical location is a key detail in determining the applicable snow zone. Furthermore, there are a number of additional parameters that determine the load to be used for designing your roof/roof truss. The same applies to stairs, where standards specify the requirements for design.

And what am I trying to say with this? Well, you should have "warm feet" before criticizing and/or informing someone else about the rules or how to do or should have done something. Just throwing out statements without knowing the facts doesn't help anyone.

 

[Hep]

[media]
I don't like the attitude?
I haven't written anything negative about TS other than that I see several flaws in the construction and get a response that there absolutely aren't any.
Whereupon TS wants to report me after an example of what could happen in a faulty construction and then comes with threats like, "hope something happens to you" etc.
I absolutely do not take offense, but I think I can demonstrate that I know what I'm talking about until proven otherwise.

Big difference between a mine elevator and a staircase between two floors, which I guess you know. You wrote about the normal case and prove it with an extreme case.

But whatever. Unlike you and TS, I'm dropping this and doing something more fun. Something I can recommend.

 

[patriklarsson]

Again, you throw out claims about which you have no clue. Like above, a roof should handle 15 tons of snow load...?...
Where do you get that from??? There are standards that dictate how one should calculate and where the roof's geographical location is a part of the information that determines which snow zone applies. Then there are several other parameters that determine the load to be used for designing your roof/truss. The same applies to stairs, i.e., there are standards that state what applies in design.

And what do I want to say with this? You should know what you're talking about before criticizing and/or telling someone else what applies or how they should or should have done it. Just throwing something out without knowing the facts doesn't help anyone.

You are wrong, I do have a clue, it was an example with snow load 1.5, but it can vary between 10-55 tons/100sqm depending on where in Sweden and which snow load 1.0-5.5 you have.
Now I don't think anyone would want to drive up about 10 cars (distributed load) onto the roof.
But that’s what it should withstand.
The same goes for stairs, they should handle significantly more than what they are normally subjected to.
If you don't understand that, you have no idea.
Provide relevant facts yourself instead of assumptions?

 

[patriklarsson]

Big difference between a mine shaft elevator and a staircase between two floors, which I guess you know. You wrote about the normal case and proved it with an extreme case.

But never mind. Unlike you and TS, I'll drop this and do something more fun. Something I can recommend.

Construction-wise, there is not much difference as the calculations are done similarly in most cases, or do you know better? You are welcome to drop it if you can't argue.

 

[roli]

Yes, unlike your 350 kg on one foot's surface, I can say that stairs in houses are designed for residential load, i.e., 2 kN/m². However, if it is a staircase in public spaces, it is designed for evacuation load, which is 4 kN/m².

 

[MrJay]

Now it has been 4 days so I assume the step is glued, finished, and tested?

 

[patriklarsson]

Yes, unlike your 350 kg on a foot's surface, I can say that stairs in houses are dimensioned for residential load, i.e., 2 kN/m². However, if it's a staircase in public areas, it is dimensioned for evacuation load, which is 4 kN/m².

You mean that if 4 steps are equivalent to 1 sqm = 204kg/sqm, then one step should withstand 51kg?
OK! That sounds completely reasonable??

 

[roli]

If you don't believe me, you might as well come up with "better information"....

 

[patriklarsson]

If you don't believe me, then you should come up with "better information"....

No, I don't believe you, because every staircase would collapse according to your claims, as every adult weighs over 50kg.

 

[richardtenggren]

In terms of construction, there is no major difference as calculations are done the same way in most cases, or do you know better? You are welcome to drop it if you cannot argue.

You might want to start by reading the Machinery Directive, as it's free and can give you a reality check
https://www.av.se/globalassets/file...t-after-29-dec-2009-regulations-afs2008-3.pdf

We often use 1.25 or 1.5 according to the Machinery Directive, but I don't work in construction. So not everyone calculates with a safety factor of 5. I have done some work bordering Eurocode, and I had to calculate on 1.5x, but it was probably a simplification of the entire thing; buy EN 109x if you're curious. Those particular assignments happened to be in a mining environment too.

I've also calculated wind load and my understanding is that there are several factors constituting the safety factor within construction standards.

For stairs, there are likely several standards, I have EN14122-3, but it has an industrial application, and it says this;

 

[Alfredo]

 

[patriklarsson]

You could start by reading the Machinery Directive, since it's free and can give you a reality check
[link]

We mostly use 1.25 or 1.5 according to the Machinery Directive, but I don't work in construction. So saying everyone would calculate with a safety factor of 5 isn't correct.
I've done some work that touched on Eurocode, where I've been told to calculate at 1.5x, but that was probably a simplification of the whole thing, buy EN 109x if you're curious.
Those particular assignments happened to be in a mining environment too.

I have calculated wind load as well and my impression is that there are several factors that constitute the safety factor in construction standards.

For stairs specifically, there are likely several standards, I have EN14122-3, but it has an industrial application and it says this;
[image]

Therefore, 153kg without or 510kg designed for load and if the stair's airborne width is less than 1200mm, the load shall be calculated centered as a square decimeter with one side against the step's edge.
I now assume that this applies to stairs where the step has an attachment at each end and not towards the center like OP, then it should be calculated according to case 2, the most unfavorable position, i.e., one outer corner.

Don't see anything strange with this, the safety factor then becomes 2.18 or 7.28.
I can only refer to what I learned in school 20 years ago, and back then we always calculated with a safety factor of 5. Naturally, I understand that it's not always the case.
Fun to learn more, I assume the staircase in this case complies with this standard?

 

[Rabbithole]

A lively thread this.

All for a staircase that has 2 obvious flaws with a crazy chamfer on the vangstycke and a long overhang in an unfavorable direction. If the steps had been in plywood, it would never have been a problem.

A risk construction where the weakness has become apparent.

Then it is possible to reinforce underneath by, for example, gluing a sheet of metal.
I would probably have temporarily glued it to later replace all the steps with new ones in, for example, furniture plywood that withstands the load better.

 

[Plupp 217177]

Feisty thread this.

All for a staircase that has 2 obvious flaws with a crazy bevel on the stringer and a long overhang in an unfavorable direction. If the steps had been in plywood, it would never have been a problem.

A risk construction where the weakness has manifested itself.

Then it is possible to reinforce underneath by, for example, gluing a sheet metal.
I would probably have glued temporarily to later replace all the steps with new ones in, for example, furniture plywood that can withstand the load better

A very good post at the end that captures basically everything technically one needs to understand.

We should create another thread about what else went wrong with this thread. Or on second thought, maybe we should forget it.

Or... we create a new thread (if it doesn't already exist) where we post things that we have built that do not meet the standards. We will all learn a lot from that I think. A thread where, like TS, we expose ourselves, showing how we thought? I will definitely dig up some sins that I have in pictures.

 

[Skyflakes]

By the way, I also think you have built a nice staircase, forgot to say that.

No, of course, even a sturdily built oak staircase will take a beating from such a blow. But it won't break like that.

And I don't believe you when you say you can stand at the edge of your steps and do small jumps without it flexing. I want to see that on film if that happens!

To the topic: lots of clamps all the way, and make sure it's clamped together completely straight. Maybe clamp downwards too.

I don't think the staircase is nice. But I respect others' design ideals, and taste is subjective, and the thread is not about aesthetics but about glue.