How to build 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

[Paolo1]

Thanks everyone.

In summary, basic frame made with 50x50x2mm Duragal SHS (with extra coat of paint). It will be connected using prefab connectors and Tek screws (not smart enough to weld). Basic sketch, not all members shown.

Cladding something like composite panels (similar to Luxapanel).

50mm concrete benchtop with 15mm Hardie Panel compressed sheet.

Area is covered, but can get a little wet on all four edges.

Threaded tube inserts with levelling feet (304SS) rated for 300kg each.

[EricL]

Hello @Paolo1 

Looking at your sketch I would hazard a guess that your concrete benchtop when joined together will possibly weigh 400++ kilograms. Your choice of using SHS is ideal, but I suggest engaging the services of an engineer or draftsperson to draw up a steel frame that will hold the combined weight of the concrete benchtops. I also recommend engaging the services of a welder to join the SHS for maximum strength.

If you have any other questions we can help with, please let us know.

Eric  

[Noyade]

Hi @Paolo1 

"It will be connected using prefab connectors and Tek screws"

Just an amateur's thought Paolo - but I think that would be a disaster waiting to happen. I have seen Tek screws sheared between steel plates.

Welding would be my recommendation as per @EricL based on the weight values estimated above.

I even think 50mm may look spindly and flex.

Your schematics above aren't to scale, but I like the proportions, so I was thinking four 100mm square vertical members connected with eight 90mm square members which gives a good 360mm weld around the edges with no weld protruding.

Talk to a steel fabricator and get their opinion and costs.

Powder coat?

That's 50mm under the measuring tape - 100m vertical - 90mm horizontal.

Cheers! Keep us posted!

[Paolo1]

Hey guys,

Yep not to scale.🙃

I'm all for over engineering something to make sure its right (its what I do for a living everyday). However, over any part of the bench, the concrete slab (say 1m long x 0.7m wide x 50mm thick) will weigh about 90kg.

There would be at least 4-6 supports with bracing in that area, so I'm ok with the connectors and tek screws 🤞. 100 SHS? The whole family could dance on that! 💃

Lets hope, I'm not back on the chat in 6 months time (with my tail between my legs) asking you advice on how to weld my 100mm steel sections.

Cheers

Paul

[Noyade]

G'day Paul. @Paolo1 

"90kg"

Well that certainly is a big drop and lighter than I thought. Please dispense with my 4" thought above then.

I'm looking at the brackets you've provided illustrations of and am looking at your middle plan with the two vertical members meeting the bottom steel.

What brackets would you use?

How many Tek screws for a joint like this?

Have you built an example to show us?

Just curious.

Cheers!

[Noyade]

Just tinkering with light hardware brackets and pop-rivets I found it felt secure, but I lost my 'perfect' 90 degrees very quickly as the drill only has to waver a fraction of a millimetre to put the joint out of square. But that is probably my poor technique and maybe clamping the steel prior would have helped.