Spiral stairs - - outdoors

[Cliff Rohrabacher]

Any one ever had a gander at a set of spiral stairs made from PT that were erected to exist out of doors in all 4 seasons?

I gots me a hankerin to have a set of stairs and I'd like a spiral. 'Ceptin I haven't quite wrapped my head around how to do it.

I have some ideas about epoxy laminations that I can do but this of full weather snow country and I don't think it'd last if it were laminate construction.

Ideas anyone?

[Jamie Buxton]

Do you mean true spiral stairs, not just curved? Spirals have all the treads hung off a central post. If so, I'd shy away from wood for the exterior application. I'd look into manufactured ones of aluminum or galvanized steel -- for instance http://www.salterspiralstair.com/. The long-term durability will likely be better than wood.

[Jeffrey Makiel]

I agree with Jamie about using wood (especially P/T) on a center supported spiral stair. Seeing the damage that the sun does to wood decking and railing, I would not trust it for this application.

-Jeff

[Cliff Rohrabacher]

When I contemplate this I can't help but imagine both a central column and an integral spiral rail-&-carriage that runs the periphery of the stairs. That would of course end up being a lamination.

Either that or a massive central column and exceedingly hefty treads. I could fashion a column from 4, 6*6 all jointed up and laminated together. Treads maybe made from 2*8 laminated to make 4*8 treads ??

[Jamie Buxton]

When I contemplate this I can't help but imagine both a central column and an integral spiral rail-&-carriage that runs the periphery of the stairs. That would of course end up being a lamination.

Either that or a massive central column and exceedingly hefty treads. I could fashion a column from 4, 6*6 all jointed up and laminated together. Treads maybe made from 2*8 laminated to make 4*8 treads ??

Y'know why covered bridges are covered? Back when wood was the only bridge-building material available, they put walls and roofs on the bridges to keep the weather off the wood. If they didn't do that, the bridge died too quickly.

If you're determined to make a wood sprial stair outside, you might consider wrapping it with walls and a roof to keep weather off the wood, just like the covered-bridge builders. As an additional advantage, you could make the walls structural -- that is, let them help support the outboard ends of the treads. (Heck, if you used the walls to support the treads, you could dispense with the central post. It'd be almost an inside-out spiral stair. I betcha there aren't many of those in your neighborhood!)