Fixing an indoor bench with green oak

[NOTTNICK]

I am about to strengthen a lovely old indoor bench that sags in the middle when sat on. I am intending to use a piece of 75 x 50 oak (2 metre length). I can get some green oak (probably air dried for a year or two) that I can plane up for a lot less than buying a dried planed board.
Do you think this would be risky? It'll be screwed / glued tightly to the underside. Or should I accept that I'll have to pay a lot more?

 

[Stigmorgan]

I imagine you will get a lot of movement and shrinkage as it dries

 

[NOTTNICK]

I imagine you will get a lot of movement and shrinkage as it dries

That's what I am thinking.

 

[Chris Puttick]

I am about to strengthen a lovely old indoor bench that sags in the middle when sat on. I am intending to use a piece of 75 x 50 oak (2 metre length). I can get some green oak (probably air dried for a year or two) that I can plane up for a lot less than buying a dried planed board.
Do you think this would be risky? It'll be screwed / glued tightly to the underside. Or should I accept that I'll have to pay a lot more?

Based on a recent experience using green oak for a deck, having a couple of stress relief grooves along the underside of the length seems to work wonders. Leftover lengths have also remained straight, although there's definitely some splits at a few ends. In case it's relevant the green oak was supplied in 3.2m planks, 38mm by ~180mm, 2 square cut grooves, maybe 10mm deep

 

[Jameshow]

I think it will be fine. Bring it inside for a few weeks to acclimatize, the bench top will hold it tightly as it dries tbh.

 

[TheUnicorn]

Based on a recent experience using green oak for a deck, having a couple of stress relief grooves along the underside of the length seems to work wonders. Leftover lengths have also remained straight, although there's definitely some splits at a few ends. In case it's relevant the green oak was supplied in 3.2m planks, 38mm by ~180mm, 2 square cut grooves, maybe 10mm deep

I've never met stress grooves, I assume they run down the length of the wood? I would have assumed that essentially weakening one side would lead to cupping?

 

[AJB Temple]

75mm by 50mm and 2 years air dried (as stated) will be fine. It's not really green any more. If it's underneath the seat, and not visible, does it even need to be oak? Is this the best way to brace it anyway - how are the ends being secured?