BEARING WALL - WOOD
Limitations of the system
Limitations of the material
1. Elastic Modulus - An important structural consideration for any material, this describes the stiffness of the wood being used, and is a ratio of stress to strain under any load before failure. Typical Elastic modulus's for Construction Grade Lumber range from roughly 5,500 to 15,700 MPa (0.64 to 2.28 million pound-feet per square-inch)
2. Size of the timber - as a natural resource, the individual timber size is very limited therefore, the maximum length of a single timber is about 90 feet, and therefore the wood frame structure cannot go very large, unless the certain reinforcement has applied such as steel or concrete.
1. Moisture condition - due to the material property of wood, the high moisture content will reduce the strength of the timber, and it is also very hard to keep the wood in a constant moisture condition
2. Temperature Variability - different temperature will have a great effect the relative humidity of the environment surrounding the wood structure, therefore the vary of the temperature will change the moisture condition of the timbers and may reduce the strength of the timber to effect the entire structure.
3. Environment Limitation - The most important aspect for the limitation of the wood frame, as a natural resource wood is kind of material without any artificial alternative, however, cut down the trees could change animal habitat, soil erosion, and recovery times due to the slow growth-rate of trees and therefore the material resource of the wood is very limited.
