Robin,

Thanks for the reply. I understand the reasoning for using steel, but my problem would be fixing it all together. I'm not into welding at all. Also, if I do go ahead with this, then I'm seriously contemplating installing it in the loft above my workshop and garage. The garage itself would be the only alternative as the workshop is already full! The garage would not be ideal as the floor is rough concrete with a gentle drainage slope towards the door. Besides, my supposed double garage is already almost full with wood store, racking for off-cuts / work in progress, workshop overspill etc. (Well, you know the way it goes. Nothing wrong with my workshop that doubling its size wouldn't put right!)

Assuming it goes in the loft, it will have to be assembled in situ due to access and, should I ever want to move it, it will have to be taken apart.

I accept what you say about leaving scope for adjustments.

Julie