Carpentry and Woodworking - Building a staircase

I want to build a stairway to my loft in my log home. To build the one that was in my original plans requires 4x12 Cypress timbers for both the "carrages", as they are referred to on the prints, and the treads. Before I commit to the expense of buying (at least $900.) and shipping ($250.-$400.) the required materials, I wanted to explore alternatives. I have on hand an ample supply of cypress 2x8 boards, and wonder about the possibility of laminating these into a home-made "engineered" substitute. A 2x12 SYP could be used as a core, as could a layer of plywood, for example. Properly done, the results should be stronger than the 4x12's in the original design, and should be easier to assemble. (The roof is on, no crane access to lift the heavy beams). Once again, I ask for opinions from the broad base of experts that visit this forum.

I have on hand an ample supply of cypress 2x8 boards, and wonder about the possibility of laminating these into a home-made "engineered" substitute. A 2x12 SYP could be used as a core, as could a layer of plywood, for example. Properly done, the results should be stronger than the 4x12's in the original design, and should be easier to assemble. (The roof is on, no crane access to lift the heavy beams). Once again, I ask for opinions from the broad base of experts that visit this forum.

Sounds like you're willing to get away from the original "log cabin look" of all 4x12 construction. Personally to me, that's fine, and I would'nt cast out all that dough either. The over bearing 4x12 treatment called for in those plans is not because the stairway needs to be that strong, but because that effect typically goes with log cabins (rough ,bulky, timber like stairs). The call for 4x12's (in those plans) is well over bearing for what a stair has to be structurally. Structurally, you could build the entire stair system [stringers (or carrages) as well as treads) out of only 2 (x) materials if you could find a design you'd like. For example:
use 2x12 pine stringers that are notched out for your treads and risers (but I would'nt install the riser boards-just leave them open) and then use your 2x8 cypress for treads (or you could get 2x12's (pine) for the treads too).
I'm not sure if I understand exactly what you have in mind for laminating 2x8's for stringers, but it's my experience that if you start out rigging........then it's going to end up looking rigged. Best aproach is the easiest approach.
If you're looking for what's easiest and what is the best on your wallet then just buy 2x12 pine for the entire construction (just make sure the lumber yard gets you #1 or #2, so you have no open knots or barked off edges-because it's an all exposed stairway.) From there you can stain it or what ever.
Hope this helps, let me know.

JW

Thank you for your suggestions. Our style of log home is one that the purists would not call a "real" log home since all the logs were milled (8" D-style) tongue and groove construction, rather than being the random sized peeled native logs. Our dining room is an off-set that has a lower roof, and has the traditional open-beam roof, while the main part of the home is conventional framed roof with a cathedral ceiling. Compromises such as this allowed the project to become a reality. The original plans were for a two story with shed dormer, and the model home we visited had one of the massive 2x12 staircases that we loved. Just before the logs were due to be milled, a back injury and subsequent loss of my job due to division closings forced a massive change in our priorities, and a long delay in the process. The second floor was eliminated, floor trusses were changed to joists, etc. The ceiling height left open the possibility of a partial loft, and that is being added back in now. For the access to the loft we considered everything from metal spiral to the original massive beams. I redesigned the ridge beam (at the suggestion of the local building inspector) to allow me to eliminate the collar ties in the prints, and this resulted in an ample supply of Cypress 2x8's for other uses. Sorry about the lengthy explanation, but I wanted to provide a better perspective. If I can use the 2x8's to create the staircase and have it look right, I would like to do so. If I cannot achieve the look that I want, then it may have to wait until I can fit the costs of the beams into my more restricted budjet. We want the open steps without risers, but don't want a fragile appearance, either. I shall experiment with the ideas presented, and hopefully find an affordable solution. Thank you all for your interest and suggestions.