Wood for a raised bed

[curium]

Hi

I'm hoping to construct a raised bed to offer an area with improved drainage.

I was going to just use some scaffolding boards rather than buying treated timber. I have previously heard that modern timber isn't treated very thoroughly anyway (only the first couple of mm).

I was wondering how long you'd expect untreated scaffold boards to last when in continuous contact with the soil?

Thanks

 

[Deleted2797112]

Here.