Oak frame stress calculations

[AlanUK]

Hi, I'm intending to build a very basic oak frame to act as a 1st floor balcony.  Dimensions will be maximum of 4m by 3m, with the long edge being against the building.  I would like to calculate how many supporting posts would be needed. I.e., would one on each corner be sufficient (along with diagonal bracing?) or would a central one at 2m be needed too?

 

Any ideas where I could find out how to work it out?

 

[Temp]

I've not read all of this yet but it looks like it has the info needed and useful construction details...

 

https://www.marley.co.uk/-/media/Files/Fixing-Instructions/TDCA-Raised-decks.ashx?la=en&hash=D5C139F512D2FF525C1A73044D89FA62

 

eg

Beam Sizes and post spacing - Para 3.4 and Table 3.1 
Wall plate - 3.6
Joist - 3.7 

Bracing - 3.8

 

 

Edited August 31, 2020 by Temp

[Temp]

24 minutes ago, AlanUK said:

would one on each corner be sufficient (along with diagonal bracing?) or would a central one at 2m be needed too?

 

Main Beams:

The guide only covers main beams (eg the beam parallel with the wall) upto 3.4m (Table 3.1). If you want to use that guide you would need three posts to reduce span to 2m. In that case they suggest main beams are 195 x 44 C16 doubled up.

 

Joists:

Table 4 suggests 195 x 45 C16 for a 3m span.

 

I don't know/think you can order oak to C16. May need to specify "Structural grade oak".

 

I recommend any metalwork in contact with the oak is stainless steel as oak can corrode other metals.

 

[AlanUK]

24 minutes ago, Temp said:

I've not read all of this yet but it looks like it has the info needed and useful construction details...

 

https://www.marley.co.uk/-/media/Files/Fixing-Instructions/TDCA-Raised-decks.ashx?la=en&hash=D5C139F512D2FF525C1A73044D89FA62

 

eg

Beam Sizes and post spacing - Para 3.4 and Table 3.1 
Wall plate - 3.6
Joist - 3.7 

Bracing - 3.8

 

 

Great, thanks - I'll take a look at that.