Balcony Loadings

[JGJ]

What loadings should I use for calculating the timbers required for a balcony?

I appreciate the normal loading is 1.5kN/m2 plus ceiling & deck load of about 0.4kN/m2 but do I need to include a snow loading or is this only required for roofs rated for "access for maintainance purposes only" with the lighter 0.75kN/m2 requirement?

I am about to re-surface a balcony using fibreglass which has 4"x2" timbers over a 2.4m span with a 300mm spacing which I calculate is okay provided no/little snow load is required. Seemed a bit light to me but if it's sufficient I don't want to replace it & the ceiling if I can help it.

On another timber component, I am considering the use of a "flitched" beam rather than a built up beam. Is the steel required for this ordinary mild steel or is it structural steel?

There is currently a long span double beam which has some rot & may be a bit small depending on whether I need to account for snow so I shall be replacing it.

TIA

JJ

 

[Taro]

Balconies in my area (USA) are required to be designed for a live load of 60 psf (2.9 kPa) to 100 psf (4.8 kPa), depending on size and occupancy. In heavy snow areas, the snow loading may exceed the live loading and control the design.

 

[JGJ]

Thanks for the reply.

I'm in the UK - I've subsequently found out that we don't factor snow load in for balconies in our building regs.

Our (UK) 1st floor balcony and internal floor loadings are both 1.5kN/m2 but balconies are additionally rated for a 0.9kN point load. Guess thats for the BBQ! :-9

Thanks again,

JJ

 

[fkd]

Here in Brazil we have to consider with the mentionated loads self wight and live load (minus snow) plus a horizontal live load of 1kN/m, applied at the top of the handrail plus a vertical live load of 2kN/m along the edges of the balcony.

Fred

 

[taff]

To JGJ

The parameters for the balcony design that you originally specified were correct. Perhaps your dead load allowance is a little light however. If you have a 3 layer felt finish, ply decking, joists, and soffitt cladding, then your dead load allowance should be of the order of 0.65kN/m2.
With regard to the imposed loads, if you allow for 1.5kN/m2 as outlined, it is likely that this loading will be in excess of any drifting snow loads. If you wanted to check this out, refer to BS 6399 which gives guidance.

The other thing to watch is if the balcony is associated with a domestic building? If not then the imposed load should be taken as the same as which the room serves. For a balcony within a bar, this will be 5kN/m2!

One last thing - is your LA Building Control officer vindictive? If so, he may ask you for calculations to justify the fixing of the handrails to the balcony deck. You have to take a horizontal load of 0.74kN/m run acting at 1.1m above balcony level for a domestic situation. It is very difficult to achieve sufficient fixity at the base of the handrail standards onto a timber floor.

Good luck!!