How to build outdoor kitchen concrete worktops?

[garytwood]

Hi All, Was hoping to pour concrete worktops in our new outdoor kitchen where 2 sides will be fully supported and steel reinforced at 40mm thick.

The "breakfast bar" I was hoping to "suspend" across the 2 brick pillars at 2180mm and 60mm thick steel reinforced.

Would appreciate anyone's opinion on whether you think this would work or would I need additional support, maybe steel box sections underside across the brick pillars ?

Thanks Gary

[Jason]

Hi Gary,

I'm looking forward to seeing this exciting project come to life. 

Apologies for the slow reply. Our resident Bunnings D.I.Y. experts are in transit at the moment so there is giong to be a bit more of a delay before one can share their thoughts with you.

In the meantime, let me tag some other helpful community members who might like to assist: @markw, @Nailbag, @tom_builds, @tony84, @jase2.

Jason

[JacobZ]

Hi @garytwood,

Thank you for your question about concrete benchtops and apologies for the delay in response.

Unfortunately, I'm unaware of any standardised information on what distance concrete benchtops like this can span unsupported, but these spans are certainly on the high side. If you wanted certainty that your benchtops can handle these spans, you would need to speak with a suitably qualified person, such as an engineer to ensure your benchtops are capable of spanning these distances.

Using steel box section or a lintel in conjunction with heavy gauge reinforcing would certainly help to support the concrete, but you would need to confirm suitability with the manufacturer of the product or an engineer.

Reducing the span by adding a central support to the larger spans is likely your best option.

Allow me to tag @Nailbag and @Dave-1 for their thoughts.

Let me know if you have any further questions.

Jacob

[Dave-1]

Afternoon @garytwood 

Ahve you had a look at a few other concrete bentchtops in here?

What concrete mix for outdoor kitchen concrete benchtop? (it is a long thread but there is a bunch of information in it.)

How to pour in place concrete countertops? 

Thats a fair span to carry the load without flexing. I do like the idea of lintels being used as that would go a long way to stop any potential flex.

I am like @JacobZ in thinking a central support would make me breath a little easier. Not saying that it would snap but may crack 😕

Just one last look at your layout and supports. Do you have anything ing mind for lateral support? In case someone pulls hard on the end edge and teh whol lot wants to rock towards you? More of a case of "what if" then a true concern as it looks like the tops will be fastened in the corner but an idea to factor in at least.

Dave

[Nailbag]

Hi @garytwood 

I share the same thoughts as with @JacobZ. Though I am not across any specifics requirements, I would expect that some form of lentil/reinforcement support will be required. Not under estimating the weight of the concrete, I would be inclined to seek advises on the load bearing requirements.

Nailbag