Glulam beam/box only own weight - max span?

[nova383]

Hello.
I want to build 2 beams with a span of about 5.5m. These should only support their own weight, 2 ceiling lamps, and 5-6 LED strips/beams. I was thinking of using 42x180 glued laminated timber, 3 pieces like a U. Screw-glued.
I find calculations but only for floor joists, roof transitions, etc., not "unloaded" so to speak.
Does anyone know or can suggest a site?

 

[largab]

The 45x90 rule should hold. Take something that looks nice. Everything will hold as long as you don't hang a swing on it.

 

[nova383]

I kind of think glulam is pretty nice, tbh. A regular beam needs to be painted or something, I was thinking the glulam just varnished perhaps.

 

[largab]

Agree, but you don't need to worry about durability with a standing beam.