How to build a home pergola?

[Chi88]

Hi there, I am planning to build a pergola and will be very appreciated if someone here can help, thanks in advance:

my area is 2x6.5sqm,(overhang is 0.5m)

90x90 4 post

183x30 as beam

138x30 as rafters

66x30 as batten

questions : can I put a max. distance(6m) of a beam(6.5m) on 1 post to the other post ? pls see image below:

what is max spacing for a beam can be supported by 2 posts?

long 6m; width 2m; height:2.4m

Post1------------------------------------------------6m-----------------------------------------------Post2

|                                                                                                                               |

2m                                                                                                                          2m

|                                                                                                                               |

Post3------------------------------------------------6m------------------------------------------------Post4

many thanks guys

[MitchellMc]

Welcome to the Bunnings Workshop community @Chi88. It's fabulous to have you join us, and many thanks for your question about constructing a pergola.

You'll need to reference timber span tables to determine the max span of your beams. Have a look at this helpful document from Hyne timber. Seasoned treated Pine F7 190 x 45mm appears to have a max span of 3000mm. Far less than your proposed distance. I recommend installing two additional midway posts over the 6000mm length. That way, your beams are only spanning 2000mm.

Check out this helpful guide on How to build a pergola. This article on How to choose the right timber for the job should also be of assistance with your project.
 

Please let me know if you need further assistance or have questions.

Mitchell
 

[Chi88]

Thx for ur advice Mitchell, in ur case i will need 8 posts in total right? That way going to limit the area then, can i reduce to 6posts for 6m spacing? Bcoz it seat at backyard next to granny flat therfore the height is limited to 2m... ideally i judt want 4 post to support the 185x30mm beams, if ok ill go to ur store to pickup all and start the project then.

Thx in advance 

Chi

[EricL]

Hello @Chi88

I recommend using 8 posts for complete support. I'm afraid the gap is too big, having a 3-meter space unsupported will make the timber bend and sag. I suggest looking at the table from Hyne timber. Not having enough support will make your pergola unsafe.

If you need further assistance, please let us know.

Eric