What span for an attached pergola?

I am building a timber pergola attached to the house. The span will be 4.2m with the facia size of 140x45.

The roof will be either corrugated iron or laser light. Will two posts be sufficient for that span. I will have rafter brackets off the main house supporting that side.

Find more posts tagged with

Tools and Materials

Building and Construction

Comments

MitchellMc

Welcome to the Bunnings Workshop community @Powerone. It's terrific to have you join us, and many thanks for your question about pergola spans.

If you have one post at 4.2 m and another at 2.1 m from the house, a 140x45 timber should be able to span those distances. That said, it would be helpful to have a quick sketch of your intended pergola layout. For example, if your pergola is 4.2 m by 4.2 m, each rafter might require a central post to span that distance safely.

Could you let us know the overall dimensions and where you plan to position the posts? That will help us determine the best timber sizes and spacing for your project. If you need assistance uploading an image of your layout, we can guide you through that as well.

Please let me know if you have any questions.

Mitchell

Powerone

https://www.workshop.bunnings.com.au/discussion/comment/58689#Comment_58689

Thanks Mitchell. I may have gotten confused with width and length. Have attached a mud map and wanted to know what size facia I need to just have posts at either end as well as how many beams at 2.4 metres. Have put 5 on the mud map but that may not be enough. Any assistance greatly appreciated.

MitchellMc

https://www.workshop.bunnings.com.au/discussion/comment/91715#Comment_91715

Great, thanks for that @Powerone.

So, no, 140 x 45mm is not capable of spanning 4200mm for your beam. You would need a post in the middle of that span to support at 2100mm. For a single span of 4200mm, you'd likely need to go up to a 290 x 45mm. 140 x 45mm would be suitable for your 2400mm rafters. Rafters need to be positioned according to the type of roofing you are using and its requirements. This would typically be around every 900mm. You'd then add purlins perpendicular to the rafters, and once again, their spacing would be dictated by the sheeting. For our Suntuf polycarbonate, that would be around every 800-1200mm.

Mitchell

Powerone

https://www.workshop.bunnings.com.au/discussion/comment/111859#Comment_111859

Much appreciated Mitchell. Thanks for clearing that up. 👍

Child Item