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.