TOIVO...............THE REASON YOU REJECT LEFT HAND SPIRAL LOGS IS THAT THEY WILL TWIST LIKE A BARBER POLE.IN A CONVENTIONAL LOG WALL THIS CAN POP THE LOG RIGHT OUT OF THE WALL.IN A TIMBER FRAME APPLICATION,ONCE MILLED THE LOG COULD TWIST AND CAUSE STRUCTURAL PROBLEMS.
[1]IN A MORTIS TENON APPLICATION IT COULD BRAKE THE JOINT AND PIN.
[2]IF YOU PLACED INTERIOR AND EXTERIOR CLADDING ON THEN IT TWISTED YOU WOULD GET AN UNSIGHTLY BUMP IN THE WALL.
[3]IF IT WAS USED AS A SILL OR TOP PLATE IT COULD HEAVE THE WALL OR RAFTERS
[4]IF USED AROUND WINDOW AND DOOR ROUGH OPENINGS FOR FRAMING.IT COULD JAM OR BREAK THE WINDOWS OR DOORS.
[5]ETC.

CORDWOODGUY