How to plan a pergola in Queenland?

[davidYR]

Hi there,

Im in the process of planning my next project and would be great some feedback as to how should I tackled it and what materials to use and quantities. I would like to build it just with Pine treated as it's cost effective.

I'm located in North Queensland so high winds we get,

Length: 7000 mm

Width :2700 mm (slab width)

Heigh: 2700mm (at high-test point above gutter)(plus roof)

Ideally I would just like it to be 4 posts but im not sure about the span. Also I would like it to have a minimum fall so water runs down into the yard. Basically it would be posts, 2beams, rafters running from the house down, battens, clear roofing sheets and lastly I'm considering so timber slats with spacing just to let the light through (slats would be installed as a ceiling from the inside).

Also what would be the best way to attached rafters to beam (considering the pitch, high winds and aesthetics)

Hope I don't get a mental breakdown before I knock this project off with all the planning and process involving this build lol. I'm excited

Kind regards 

"Goal"

"My backyard"

[StevieB]

Welcome @davidYR. Sounds like you've got an exciting project ahead of you and thanks for reaching out to the Bunnings Workshop community. We're here to help along the way.

Bunnings has a series of videos about how to build a pergola, which includes building the pergola frame and constructing the roof. That would be a great place to start.

Our resident D.I.Y. expert @EricL will be happy to help with any questions when he's back on the site on Friday, and helpful members such as @tom_builds and @DIYgals may be able to offer suggestions too.

Look forward to seeing this project come together.

Stevie

[tom_builds]

Hi @davidYR,

Looks like you have a decent project on your hands.

One thing I would recommend is getting in touch with your local council to see if they can tell you what the wind rating is for where your home is, as being in North Queensland your wind rating will be Cyclonic and - depending on where your home is located - could require an engineer to sign off on your design (if it is a C4 rating).

Otherwise, working on a C2 rating, to span a 7000mm length you will need at least 6 posts, and either double beams of 190x35mm pine or a single 240 x 45mm beam on each side. Your rafters would need to be 120 x 35mm minimum to span the 2700mm @ 600mm centres (requiring 13 rafters) or 140 x 35mm for 900mm centres (requiring 9 rafters), and for all of these I've used the spans of treated pine so you will have no issue there. For attaching the rafter to the beams I would recommend notching them (remembering to accomodate for the fall towards the garden) and using framing anchors to secure them. Framing anchors can be primed and painted over to match the rest of the pergola.

Hope this gives you a start on your planning, we look forward to seeing your project progress.

Best of luck!

[davidYR]

Hi Tom, 

I appreciate your response mate, great advice!

I get it will have to be a 6 post built. Also I was thinking to place the Beams (3 of them) parallel to the house and run the Rafters from the highest point of the pergola down into the lowest point. The length of the pergola would be determine by the longest rafter available I can get in treated pine at Bunnings (is a 6 or 7 meters rafter size a thing?) and is this a viable approach to the pergola built. 

Regards

Ps. picture for reference 

[EricL]

Hello @davidYR

It's great that you've received fantastic advice from @tom_builds. I recommend talking with your store's Trade Specialist if you are trying to source rafters at the length you've mentioned. The Trade Specialist will be able to source and organize the delivery of this type of timber to your home. However, if it turns out that there is a limit to the length available you may have to modify your current plans. If you need assistance ordering the rafters, please let me know. Please keep us updated, I'm sure our members are keen to see the start of your build.

If you need more advice or information, please let us know.

Eric