How to mount a pergola to corrugated iron wall?

[Xfixiate]

Hi,

I want to build a pergola off my garage. Garage Cladding is corrugated iron horizontal.

How do I attach the beam? I've been looking online for spacers that suit corrie without any luck.

Cheers 

[MitchellMc]

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

To mount a pergola beam to a corrugated iron wall, you'll need to ensure a secure connection between the beam and the structure. However, the corrugated sheeting poses a challenge as it hinders direct contact between the beam and the wall. To establish a positive connection, you'll likely need to cut away the corrugated sheeting to expose the internal beam, allowing for proper attachment with bolts without compromising stability. While spacers might offer a solution, they likely wouldn't provide the necessary structural integrity or comply with construction codes, making the direct connection a safer choice for long-term stability and durability.

Before proceeding with attaching the pergola to your garage, it's important to have the garage structure assessed to ensure it can support the additional weight of the pergola. Consulting with a structural engineer or a builder will help determine your garage's load-bearing capacity and ensure that the pergola's installation won't compromise the integrity of the existing structure. 

Please let me know if you have any questions.

Mitchell
 

[Xfixiate]

Thanks Mitchell.

Structure is an old very sound garage. Was hoping to avoid cutting into the wall to maintain weatherproofing. Wall studs are 70 year old hardwood so the large countersunk 14g framing screws will hold it. 

[MitchellMc]

Hi @Xfixiate,

Framing screws would certainly hold the beam in place, but to the best of my knowledge, that would not be a connection approved in construction codes.

A structural connection is not possible when a compressible material like corrugated iron is between two structural members. The corrugated iron lacks the rigidity needed for a secure attachment, as it may compress or deform under pressure, compromising the stability of the connection. Removing the corrugated iron exposes the internal beam, enabling a direct and robust connection for the pergola and ensuring safety. 

Weatherproofing can be reinstated with the use of appropriate flashings.

Mitchell

[Xfixiate]

Oh absolutely correct.

Was hoping to find a corrugated beam or intermediate profile that would sit between the beam and the  corrie. I can then bolt through that straight to the carport uprights, which would be flush to the inner part yet stand off the corrugated iron. Bolted top and bottom to the uprights. I've seen something similar years ago but not recently.  

Hope that makes sense.

[MitchellMc]

Sorry, I presumed you were thinking of individual spacers for the fixings @Xfixiate. A solid corrugated profile sounds like it could be an option, though I am unaware of any that would suit.

You might like to add some images of the area so our members have a better idea of possible solutions. Let me know if you need help uploading images. I'll tag @Dave-1, @Nailbag, and @TedBear for their thoughts.

Mitchell

[Xfixiate]

Like this... a steel or timber profile matching the corrie on one side, flat on the other for securing the beam through the beam, thriugh the spacer, to the uprights. A lip at the bottom to hold the beam until screwed through would be a bonus...

 

[Xfixiate]

Obv span two corrie troughs, even a hanger would work with a corrie profile.

[Dave-1]

Afternoon @Xfixiate 

I can picture what you are talking about and truth be told I would be thinking the same thing. The only issue would be that the corrogated spacer/timber needs to be both sides so the tin cannot compress. Looking at your picture (hoping its just not an example pic lol) Wondering if your roof trusses could be extended ? Not sure structually if its wise. Or mount that timber strip above the corrorgated iron befor the roof trusses?

Dave

[Noyade]

Evening @Xfixiate 

"span two corrie troughs"

I think this is the important thing, once you bolt to the studs behind the corrugated iron - I don't think you need a corrugated profile.

I used treated sleepers to make that span, very much like your photo above...