The Norwegian lock is a method for connection of two logs. It differs from common cupping by complexity of manufacturing. The basic advantage of such method of connection is self-jamming. Angular connections are positioned very tough and precisely and under the weight of a blockhouse and rafter systems they become self-sealed.It makes blowing off in corners and water leakage impossible. As a result, corners remain much warmer, than at any other methods of house cutting. There is no rotting of wood, logs do not curl under the influence of internal pressure.