Log home are constructed of logs, these logs are composed of various layers of wood cells. These cells differ with tree species in terms of function, size, concentration, proportion and chemical composition. They determine how trees grow, how they react after they've been cut for logs, and what properties they have that make them good (or not) for home construction.
Checks, spiral grain, knots, insect holes and logs with sweep and taper are commonly found in log homes. These imperfections are not defects and are to be expected in most homes. It's only when they cause problems that they are considered defects.
The natural bowing in a log is called the Sweep. Taper refers to the difference between a log's tip and butt diameters. Log tips and butts alternate in a wall. When they're built correctly, log walls can accommodate logs with considerable taper. Extreme taper itself is not a defect. Knots indicate where branches grew in the live tree, and may be tight or loose. Knots affect the angle of grain as wood fibers bend to grow around the limb, so they may have an effect on log strength, but determining the extent to which this condition is a problem would require the services of a certified log grader.
Any plant species that grows taller than 20 feet when mature and has a dominant single stem (i.e., the tree trunk) can be referred to as a "tree." Plants that mature at less than 20 feet are called shrubs and aren't used for building. Wood is divided into two types, both of which (in North America) exhibit annual growth rings, but which perform different primary functions in the tree.
Sapwood helps to support the tree, but its main function is to transport water and mineral nutrients from the soil to the leaves. Its cells also store carbohydrates and provide protection. Sapwood is typically light in color.
Heartwood is composed of dead cells and is a main source of structural support. Heartwood cells also store extractives (including toxins) safely. Extractives give heartwood its typically darker color. Extractives include tannins, oils, lignins, fats, resins, waxes, gums, starch and terpenes. They're called "extractives" because they can be extracted from wood by heating it with water or a solvent. Extractives have commercial value.
No dependable means exist for identifying log wood species in the field by examining logs with the unaided eye. Inspectors may build a library of log photos of wood species commonly used for building log homes in their area, but this will be a general reference, at best.
The most effective method of identifying wood species is through the careful examination of wood cell arrangement. This requires a microscope or a hand lens. Wood texture, color, taste and odor also offer clues.
In a log home, the wood helps provide some insulation. Wood's thermal resistance or resistance to heat flow is measured by its R-value. The higher the R-value, the more thermal resistance.
Part of an inspector's job is to recognize and comment on signs of existing failure, allowing their client to negotiate for corrections and preventing future damage. Sometimes, no signs of failure may be visible at the time of the inspection, especially in newer homes. In these situations it's up to inspectors to recognize conditions which will eventually cause failure if not corrected.
The forces which typically cause failure in log homes are the following: Soil movement, Decay, Wood-destroying insect activity, Poor construction practices (design, materials or workmanship), and Log movement. Hiring a competent inspector is paramount to protecting your investment.
Checks, spiral grain, knots, insect holes and logs with sweep and taper are commonly found in log homes. These imperfections are not defects and are to be expected in most homes. It's only when they cause problems that they are considered defects.
The natural bowing in a log is called the Sweep. Taper refers to the difference between a log's tip and butt diameters. Log tips and butts alternate in a wall. When they're built correctly, log walls can accommodate logs with considerable taper. Extreme taper itself is not a defect. Knots indicate where branches grew in the live tree, and may be tight or loose. Knots affect the angle of grain as wood fibers bend to grow around the limb, so they may have an effect on log strength, but determining the extent to which this condition is a problem would require the services of a certified log grader.
Any plant species that grows taller than 20 feet when mature and has a dominant single stem (i.e., the tree trunk) can be referred to as a "tree." Plants that mature at less than 20 feet are called shrubs and aren't used for building. Wood is divided into two types, both of which (in North America) exhibit annual growth rings, but which perform different primary functions in the tree.
Sapwood helps to support the tree, but its main function is to transport water and mineral nutrients from the soil to the leaves. Its cells also store carbohydrates and provide protection. Sapwood is typically light in color.
Heartwood is composed of dead cells and is a main source of structural support. Heartwood cells also store extractives (including toxins) safely. Extractives give heartwood its typically darker color. Extractives include tannins, oils, lignins, fats, resins, waxes, gums, starch and terpenes. They're called "extractives" because they can be extracted from wood by heating it with water or a solvent. Extractives have commercial value.
No dependable means exist for identifying log wood species in the field by examining logs with the unaided eye. Inspectors may build a library of log photos of wood species commonly used for building log homes in their area, but this will be a general reference, at best.
The most effective method of identifying wood species is through the careful examination of wood cell arrangement. This requires a microscope or a hand lens. Wood texture, color, taste and odor also offer clues.
In a log home, the wood helps provide some insulation. Wood's thermal resistance or resistance to heat flow is measured by its R-value. The higher the R-value, the more thermal resistance.
Part of an inspector's job is to recognize and comment on signs of existing failure, allowing their client to negotiate for corrections and preventing future damage. Sometimes, no signs of failure may be visible at the time of the inspection, especially in newer homes. In these situations it's up to inspectors to recognize conditions which will eventually cause failure if not corrected.
The forces which typically cause failure in log homes are the following: Soil movement, Decay, Wood-destroying insect activity, Poor construction practices (design, materials or workmanship), and Log movement. Hiring a competent inspector is paramount to protecting your investment.
About the Author:
Napoleon Home Inspections has over 4,000 inspections and is considered the Premier Home Inspector in the Barrie and Simcoe County area. Learn about the Barrie Home Inspector Services before buying your home.
0 comments:
Post a Comment