For windows and doors, any good quality wood framed unit may be used. As log wall systems "settle", windows and doors are installed inside a 2 x 10 “rough buck", and attached to the log work with an angle iron spline. 1 X 6 is used for casing to interior and exterior of windows and doors. Flexible membranes and sealants are used to achieve weather-tightness and to meet building codes.