Unsupported Oak

How thick is the oak, just over a metre isn't really a big gap, so if the oak is thick, it shouldn't be a problem.

 

Presumably there is a supporting rail along the back wall (presumably there is a back wall!)?

In which case it should be 'ok', but will also likely bow a small amount.

I think you should explain to the customer that - in your judgement only - it 'should' be ok, but is clearly not recommended as Magnet provided a supporting 'leg'.

After all, neither Magnet or yourself will have any control over how that worktop is treated in future; whether 'kitchen party-goers' make it a habit of sitting on that unsupported section, for instance. Therefore, although it 'should' be fine, and you are happy to do as the customer requests, they should acknowledge that this part is accepted as being 'at their risk'.

If you really want to cover yourself, make sure your final invoice also includes that proviso.

Perhaps you could also add that if they monitor the worktop and let you know immediately if there's any sign of bowing, you are happy to come back and fit that leg FOC. But only if they inform you before it becomes a serious issue that'll be hard to resolve.

Also make sure they acknowledge that Magnet will not warrant that length of worktop should it bow.

 

Had a similar set up in the craft room at last place, worktop is beech though, it's sat on units with 1050mm opening between units, I screwed two lengths of 4mm or 5mm flat bar 40mm wide to the underside of the worktop over the opening, never bowed in 5 years.

 

40mm solid oak over a 1M span. Relax, that aint gonna bow.

 

Exactly, and if it does, it ain't oak.

 

I would suggest fitting a 3"x1" across the centre as an upstand support from unit to unit. One thing against the span is not having the worktop longer than 350mm after the span, so there is no long run keeping the outer ends down.
(Assuming this is an island!) If it's not an island, scratch that.

Mr. HandyAndy - Really

 

According to calculations a 300kg load placed in the middle of the span will cause it to deflect by less than 0.5mm.

 

So no fat birds allowed at parties.

 

Fat birds would spread the load so deflection of only 0.2mm and 300Kg is really fat so doubt they could get on the worktop in the first place.

 

Just hit the trail and never look back.