5 mm ply for the base board
15 mm square spruce for the frame
1.5 mm ply for the elevated sections and tunnel cover (landscaping to be applied over the top)
3 mm square spruce to act as beads/gussets on the elevated sections and tunnel cover
Does that sound about right or do I need to go 9 mm on the baseboard? I'll probably use a 122 x 61 cm sheet as that's a standard size.
Regards the frame will a single cross brace making two squares of around 61 x 61 cm be enough or do I need extra bracing to make it 8 squares of 30 x 30 cm?
I'm not planning a fiddle yard and the controllers will either be on an empty corner of the baseboard or maybe a hinged flap. Not sure yet. Layout diagram attached.
