# Forum Home Renovation Pergolas, Gazebos, Strombellas & Rotundas  Pergola Beams & Rafters - Please Help With Spans & Sizes?

## marvel25

Hello Everyone, 
I need help in determining the correct timber sizes for a DIY pergola (& eventually add a polycarb roof) project. 
Here is a sketch of the side of the house where I would like to put up a pergola.   
It is *7.6 metres* by *2.13 metres*. The roof has a pitch of *22 degrees*. 
The height of the of side walls are approximately as shown below, *2.6 metres* & *3.3 metres*:    
Here are sketches of the timber members of the proposed pergola:     Beam Front Side = 2 pieces - 190 x 45 @ 3.8 metres longBeam Back Side Bolted to Brick Veneer = 2 pieces - 140 x 45 @ 3.8 metres longRafters = 10  pieces - 140 x 45 @ 2.4 metres long (@ 760mm spacings)Battens / Purlins to run across the 7.6m length = 4  pieces - 70 x 35 (maximum of 900mm spacings)Post = 2 pieces - 100 x 100 @ 2.6 (@ 2.5m spacing) posts will be bolted to stirrups   *Can anyone please help confirm if these timber sizes are appropriate, and if not kindly post your recommendation?* 
Thank you in advance!

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## cherub65

All good, would have beam flush with bottom of timbers then no need for batten at front.
Place posts at both ends of beams.

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## marvel25

Hi cherub65, 
Thank you for the very quick reply!  :Biggrin:  
As you've pointed out, I will align/flush the bottom of the front beam with the rafters, to eliminate need for front batten.  *A question/clarification on about your second recommendation to place post at both end of the beams -*  
Do you mean like to do this as shown in this sketch?   
Or to cut the posts so that the Beams sit on top of the posts?    *Thanks again & hope you have a great day!*

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## cherub65

Post either end then post in center at join, will give you more space.

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## ibuildbenches

Just has a quick look at my F17 span tables and you could use 90 x 45 for your rafters and 140 x 45 for your front beam, with a single post in the middle. Or use a 240 x 45 for the front beam and have no posts at all. Might save you some coin? 
What program do you use for your sketches if you dont mind me asking?

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## marvel25

Hi Matt, 
Thanks for the reply!  *With the 240 x 45, it can span the 7.6 metres without needing a post?*  
That should be interesting/great! 
I'll re-sketch the pergola tonight with your recommendations and post it. 
The program that i use is SketchUp 7 from Google.  Google SketchUp 
Thanks again!

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## cherub65

Matt, you wont get a 240 x 45 mm at that length unless you go to manufactured  beams, so you wont be saving coin

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## Bloss

The sketch seems to show attachment possible at either end so IMO it'd be better to use a suitably sized single beam (eg: HYNE - Hyne LVL)  and no posts even if at the extra cost for the beam. Easier construction save the cost of posts and I reckon simply looks better. But this needs design certainty and solid construction knowledge & competence form a DIYer.

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## marvel25

Hi Folks, 
Here are some photos of the side area of our house where the I would like to construct a pergola:  In the photo you can see there is a fence which is on the "zero lot line" on ours and the neighbours property. Also please take note of the down pipe.  On this photo is the other end of the side area.      
Also, to give you an update & again ask for advice:I went around the timber & hardware stores for qoutes in my area and Mitre 10 South Morang seems to have the best price.@ *cherub65* - you are right. the 240 x 45 is expensive & is not readily available for my required length.*Bloss -* thanks for replying.  :Smilie:  I must say that this will be my *first major DIY* project & I do not have design certainty & solid contruction & competence of an experienced DIYer. I am very thankful for the members of this forum & am inspired by the so many other people out there who have made great successes in their projects. :Biggrin: In going around for sourcing & quote for the materials, it is feasible/possible (from the Australian Standards/Building Codes/ and aesthetics perspective) for me to "downgrade" with the following timber sizes: *Beam - front = 140 x 45 @ 3.8m (2 pieces joined) (With 1 post support at centre or at the join)**Beam - bolted to brick veneer = 140 x 45 @ 3.8m (2 pieces joined)**Rafters - 90 x 45 @ 2.2m (10 pieces) at 760mm centres*What is the proper bolting/fasteners required to bolt the brick veneer in terms of diametre & length for the: 140 x 45 beam to the wall?90 x 45 rafters at each side wall?The minimum number of bolts & the spacing required to ensure that the beams/rafters is secured & solidly attached to the wall?Thanks again for you replies & advice!

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