Beam Span Weight Limit : Calculation

[dibbers006]

The initial message was deleted from this topic on 15 December 2023 at 23:16

[Tom_C76]

What exactly do you want to fix? Are we talking about a hanging chair of some kind, or a hoist that can be at any point on the beam?

[V8RX7]

So you want to build another floor in the corner of a room ?

Who says it's 300kg load ?

The floor itself could weigh that.

[motco]

Evenly distributed (live, like a lot of small sacks laid side by side), or central load? Makes a difference.

[V8RX7]

No sane person would build it with a 300kg design load - what if 4 people went up for a look ?

[Desiato]

dibbers006 said:

I guess I was using child sized calculations.

What would you recommend?

From memory you should be looking at 1.5kN/m^2(152kg/m^2) for live loads on a domestic floor plus any additional dead loads including self weight. (5kN if it's industrial, unless you know exactly what will be there and it weighs more than that.)
For the connections to the brick, piers etc the load should be factored by 1.2 for live loads. Deflection checks don't require factored loads but need to be carefully taken into account if you are having any plastered walls etc fixed to your new floor. Use L/500 as a maximum deflection limit.

I can check this properly at work tomorrow if you don't get any better answers.

[Tom_C76]

Load factor for imposed loads is 1.6, not 1.2

Post a decent pic and I'll have a look, but the other thing you'll need to consider is the cantilever out from your beam and how you anchor it down unless the floor area is cut on the angle to match the beam.

[V8RX7]

How far along the walls are you going ?

If it were my house I'd simply overbuild it, if I understand it correctly and it's a Home then I'd want a Struct Eng to sign it off.

Off the top of my head for say 2.5m along each wall and a diagonal of approx 3.5m I'd bolt 8x2 timbers to the walls and run 8x2 diagonally between them at 400 centres with an 18mm P5 floor.

Edit - looking at you pic again you want to cantilever over a beam - it's all getting a bit OTT for a play space - diagonal steel beam sunk into walls (or a maybe a double 8x2 timber) 6x2 timber joists oversailing (depending upon size)

Edited by V8RX7 on Wednesday 30th March 23:22