Choice of H-beam for patio.

[Eddie_ja]

I hope I'm writing in the right part of the forum.

I have a problem with the sizing of a beam.

Conditions: I am going to build a deck of 7*10m. This deck will be above a patio roof, and I will place two beams on each side of the roof and one that spans across the roof. This beam will not have support and will need to span 9 meters. What I'm considering is placing an H-beam in this location as I want to minimize its height as much as possible.

Can anyone help with how I should proceed to determine the right size? Or if I'm thinking completely wrong, comments are welcome too.

Best regards, Eddie

 

[Eddie_ja]

Hehe, it wasn't that interesting, I notice.

I have found a good table http://viewer.zmags.com/showmag.php?mid=wrwrdq#/page62/ where I conclude that an HEB 300 is required to do the job.

I see there that with 4550 kg load evenly distributed over the beam, the deflection is 95 mm. Does anyone know the formula for deflection if, for example, there is 1000 kg evenly distributed?

I have found a used beam 28 cm high, 35 cm wide, could this be as strong as an HEB 300? http://www.blocket.se/vi/13139659.htm?ca=15_s

Grateful for answers if anyone has a moment to spare.

 

[fresve]

This deck will be over a roof terrace, I will place two beams on either side of the roof and one that spans across the roof.

Can you explain that further? Is it a balcony you're going to build?

 

[Eddie_ja]

Oops, there was a little mistake. This terrace will be situated over a vekstad roof (the workshop is underground, only the cocoa sticks up).

 

[Eddie_ja]

* The roof should say not the cake

 

[anaitis]

Hehe it wasn't that interesting I notice.

I found a good table [link] where I concluded that an HEB 300 is required to do the job.

I see there that with 4550 kg load evenly distributed over the beam, the deflection is 95 mm. Does anyone know the formula for deflection if, for example, you have 1000 kg evenly distributed?

I found a used beam 28 cm high 35 cm wide, can this be as strong as HEB 300? [link]

Grateful for responses if anyone has a moment to spare.

You need to read the fine print again! The possible load described for the beam you looked at (q) is 45.5 kN/m. This is not "4550 kg load evenly distributed over the beam" but significantly more!

Moreover, the deflection for uniform loads is directly proportional to the size of the load. That is, if you have 10 kN/m instead of 45 kN/m, the deflection will be about 21 mm.

Do you have a load of 10 kN/m? How did you arrive at that if so?

 

[anaitis]

I have found a used beam 28 cm high and 35 cm wide, can this be as strong as HEB 300? [link]

Grateful for an answer if someone has a moment to spare.

I have looked at Blocket now too: The beams visible there are welded plate beams. Without having exact measurements of the cross-section, it's not possible to say if they are strong enough. You should be able to get data from the company selling them.