Can the beam handle it?

[Lolight]

I built a new roof on my garage.
The new roof turned out like this.

It is approximately 10 meters long and 4.4 meters wide.
I installed a beam of 4.4 meters across after 6 meters, dividing the length into a 6-meter and a 4-meter section.

Then 190 mm beams (7 of them) were hung on this cross beam.
Tongue and groove flooring 22 mm. Roof slope 3 degrees.
Insulated, slatted wood paneling, then gypsum board on the ceiling.

So my question is, the beam I built is made of 3 pieces of 220x45 mm and is 4.4 meters long, glued together, and bolted.
But now I wonder if this cross beam can support the weights?
They are regular 220x45 boards.

Thanks in advance

 

[huggan]

When I calculate it, a 140*270 glulam beam is needed, with a utilization grade of 92%. This is for snow zone 2 and no insulation or underroof.

You have 135*220, so you are close but slightly under. Snow zone 2 means it can handle the dead load + 200 kg/sqm snow load. Wet snow can weigh up to 400 kg/sqm, so when it starts to reach half a meter of snow, you simply need to shovel the roof.

 

[Lolight]

När jag räknar på det behövs 140*270 limträbalk, nyttjandegrad 92%. Detta vid snözon 2 och ingen isolering eller undertak.

Du har 135*220 så du ligger nära men i underkant. Snözon 2 menar att den klarar egentyngden + 200 kg/kvm snötryck. Blötsnö kan väga upp till 400 kg/kvm så när det börjar bli en halvmeter med snö får du helt enkelt skotta taket.

Har kollat och mätt lite. Det är längre än 4.4 snarare 4.9 meter.... Inser att jag får ta och förstärka med en stålbalk. Det finns ju bra med takhöjd som det blev nu och jag vill vara på säkra sidan.
Så då kommer man till hur beräkna en sådan I-balk ? Vad ska jag fråga efter hos stålhandlaren?

 

[huggan]

You use this formula to calculate the deflection 5*Q*L^3/384*E*I. Deflection should not be more than L/400.

Q is the distributed load in Newton
L is the span
E is 210,000 for steel
I is a value that depends on the type of beam used and its dimensions