# Forum Home Renovation Pergolas, Gazebos, Strombellas & Rotundas  Single span verandah - is 5800mm possible

## konazz

Having a discussion w/ my carpenter and trying to decide on the pergola beam. He's happy with a 290x45mm beam, but I'm thinking it should be around 310 high. 
Single span- 5800mm
Attached to brick wall on one end (custom 300mm deep bracket, with 8 chemset bolts) and checked in on a 112x112mm H3 post 
RLW is 1100mm with 900mm joist spacing. Laser light sheeting, so should stay under 10kg/m2 
Is it possible to get a away with a single span, or do I need to put in another post (which I'd rather now, to keep it as open as possible). Height clearance is not an issue, so can go taller beam.

----------


## pharmaboy2

Do you have an engineer?  I’ve seen 300/45 x2 with 8mm steel sandwiched between as a composite achieve spans of that magnitude .  Not that hard to manufacture on site, and you could probably prop the centre 10mm higher while bolting or screwing through.  
Actually, maybe that’s all way overkill - just double it to 2x290/45 - cos verandah beams often sag when at the limit

----------


## konazz

Do I need an engineer? Steel was an option (we can do the whole thing in steel) but I'd rather keep the look of timber as the house is a cottage with a front timber verandah. 
Would 2 x 290/45 be ok? Probably bump the post out 135mm x135mm to make it stronger. 
I'm trying to find the rules around unsupported spans on the NSW government website. I know in ACT, spans greater than 4m need to have a BA certificate (still DA exempt). My last pergola from Spanline needed a BA as it had 5.2m unsupported and 3.6m above ground level. 
I'm thinking more and more to add a post in the middle, giving me spans of 2900mm, which I can deal with easily

----------


## pharmaboy2

Download a calculator .  5.8 is beyond most of the std tables, so you might need a calculator   http://www.tpd.net.au/GL8%20Light%20...Beams%20N2.pdf

----------


## konazz

I found a supplier who does 290 x 65 GL8, which should comfortable span. Need to determine whether I need an engineer to sign off on 5800mm span. 
Thanks for the link Pharma!

----------


## intertd6

> Having a discussion w/ my carpenter and trying to decide on the pergola beam. He's happy with a 290x45mm beam, but I'm thinking it should be around 310 high. 
> Single span- 5800mm
> Attached to brick wall on one end (custom 300mm deep bracket, with 8 chemset bolts) and checked in on a 112x112mm H3 post 
> RLW is 1100mm with 900mm joist spacing. Laser light sheeting, so should stay under 10kg/m2 
> Is it possible to get a away with a single span, or do I need to put in another post (which I'd rather now, to keep it as open as possible). Height clearance is not an issue, so can go taller beam.

   F17 USHWD 290 X 68 will span that distance.
inter

----------

