"Strength" glulam 115x115?

[Per Sandwall]

Hello!

I am planning to build a simple pergola using glulam, which I will paint. I plan to construct everything in the dimension of 115x115 mm.

How long can the span be between the wall and the pillar without the "beam" bending to the point where it’s "visible"? The span from the wall to the intended pillar is 4.3 meters. (see image)

On the beams, I am planning to lay strips of 45x45 mm with approximately 30 cm spacing.

Thank you in advance!

Best regards, Pelle

 

[Mikael_L]

If you don't have any snow load to consider, you can have a large span without any problem.
I can't do the calculations, but I can't imagine 4.5 meters being a problem.

But what's the reason you want to use a square profile 115x155 for horizontal beams? It becomes significantly more robust, sturdy, and has more load-bearing capacity, and it's cheaper if you use, for example, 45x170 studs.

 

[Per Sandwall]

If you don't have snow load to consider, you can have a considerable span without problems.
I can't calculate, but I can't imagine 4.5 meters being a problem.

But what is the reason you want to use a square profile 115x155 for horizontal beams? It would be significantly more solid, steady, and have more load-bearing capacity, as well as being cheaper if you go with, for example, 45x170 joists.

Thanks for the response. It's more an appearance question, I like that profile.

 

[Knight]

Glulam 115x115 isn't that a column and should only be loaded vertically? Glulam is so cheap. 90x270 costs nothing.

 

[Per Sandwall]

Limträ 115x115 isn't that a pillar and should only be loaded standing? Limträ is so inexpensive. 90x270 costs nothing

Thanks for the response. As mentioned, I like the square profile more.

 

[Pasjostrom]

I can't answer regarding the glulam posts, but it won't work to have 45x45 on top. How long will the span be? You probably need at least 45x95 depending on the span.

 

[Per Sandwall]

Ok! Thanks for the input.

 

[ArneTW]

It's not a major investment and the load is small.

I would just have built it, and if it sagged, you could fix it then.

/ATW

 

[Per Sandwall]

Ok, thank you for the response.

 

[Mikael_L]

I can't answer regarding the glulam poles, but it won't work to have 45x45 on top. How long is that span going to be? You probably need at least 45x95 depending on the span.

Yes, what span will it be?
In the picture, it seems to be maybe 2-2.5 meters, surely a 45x45 can manage just carrying its own weight?

However, it's a bit difficult to find a 45x45 stud of such quality that it doesn't twist and warp.

 

[LeffeA]

Consider which snow zone you are in. Affects calculations and easy to miss.

 

[Per Sandwall]

Consider which snow zone you are in. It affects the calculations and is easy to overlook.

Ok. Västervik.

 

[Mikael_L]

A pergola doesn't bear any snow at all, does it?
It's not a roof, just slats.

 

[Per Sandwall]

A pergola doesn't really carry any snow at all?
It's not a roof, just slats.

A few flakes will probably stick.

 

[LeffeA]

Ok. Västervik.

OK Västervik. Not much snow there.