Outdoor BBQ Framing

[Paolo1]

Hi,

I'm building an outdoor bbq (on a concrete slab under a standalone steel pergola). The frame will be constructed with steel channel and will have a concrete benchtop (50-60mm thick). I would appreciate some advice on two questions.

Is the Siniat 75mm channel framing below adequate or should I use a heavier channel (ie. Stratco 75mm 1.2BMT)?

https://www.bunnings.com.au/siniat-76-x-3000mm-0-50bmt-steel-track-wall-siniat_p1091043

https://www.bunnings.com.au/siniat-76-x-2400mm-0-55bmt-steel-stud-wall_p1091176

Can I place the channel directly on the concrete? The area is covered, however the perimeter can get wet.

Any help would be appreciated.

Thanks

Paolo

[Jewelleryrescue]

Hi @Paolo1 

I like your thinking

But I don't recommend that steel under a heavy concrete BBQ top as that steel is not load bearing for one. For two that steel is galvanised but is not really ready for frequent immersions, you are better of using cut up aluminium posts braced diagonally or with supported fillet angle brackets in each corner as a direction change. the slab will need supports all the way under it as they are strong but brittle too, so more than just corner posts.

I would use brick work under your table slab as it is long lasting and can handle the weight and spread the load

Not what you wanted to hear but you don't want a cement slab collapsing down on you.

[Paolo1]

Thanks for the quick response. 
I’m not too concerned with the structural adequacy of the gal steel frame (if using the heavier 1.2mm thick). I was trying to be cheap and use a lighter section. 
However, I do agree with you about the channels being subjected to water. That bit worries me. Might think on it a bit more. Cheers 

[Jewelleryrescue]

Hi @Paolo1 

The steel you can always  spray paint additional layers of Galvanised paint over the surface as a second protection not just the factory coating . Cover especialy the cut edges that are exposed metal.

You  can  sit the steel on a10mm rubber mat strip so its out of pooling water longer, Little tricks like that.

I like coating the colourbond  fence posts with bitumous  paint for longer ground life.

Rememer to brace the steel  diagonally i use stainlesssteel  wire as used for  fencing applications.

Enjoy your project.

[Paolo1]

That’s for the info. Appreciate the help. Cheers. 

[MitchellMc]

Hi @Paolo1,

I agree with Jewelleryrescue's point that the Siniat channel framing is not structurally rated for such a heavy application as a concrete benchtop. The framing material you use needs to support the weight of the concrete slab, and the strength of the framing is critical in ensuring that the slab remains stable.

The width and length of the benchtop, along with the distance between support points, will determine how much structural support is needed. For shorter spans, reo-mesh within the concrete may provide sufficient reinforcement, but for longer spans, you would need to incorporate galvanised lintels or stronger structural elements to provide the necessary support and prevent failure.

Overall, I’d recommend reviewing the span and weight loads, and possibly consulting a structural engineer to ensure the design can handle the load safely and efficiently. 

Please let us know if you have any questions.

Mitchell