Different Types of Defects in Timber

Table of Contents

DEFECTS DUE TO CONVERSION

DEFECTS DUE TO FUNGI

DEFECTS DUE TO INSECTS

DEFECTS DUE TO NATURAL FORCES

Impact in Timber

Bowing in Timber:

Cup in Timber:

Check-in Timber:

Split in Timber:

Twist Wood Defect:

Honey Combing in Timber:

Timber, as you now know, is a valuable resource in the building industry. Doors, windows, and walls are all common examples of wood's structural applications, while secondary wood products like plywood, particle boards, laminated boards, etc. account for a sizable portion of the material's overall demand.

There are two types of wood used: hard and soft. Therefore, the structural safety of buildings may be compromised by flaws in this construction material. Besides its purely aesthetic value, fire protection. Because timber is a natural material, it inevitably has flaws like anything else made from nature.

Most timber faults result in a lack of strength or other issues. For example, a bowl fashioned from twisted wood would be a fantastic example of how some flaws may prove useful.

DEFECTS DUE TO CONVERSION

• The term "boxed heart" describes timber that has been sawn so that the pith, or central heart, remains totally within the surface throughout its length.
• Overheating is primarily to blame for the machine's burnt condition.
• Notches in machinery result from improper holding and tugging.
• Wood with this flaw has been improperly cut or sawn. The most common causes of sloppy sawing are inexperience and carelessness.
• Incorrect Grain Alignment; Imperfect Grain.

DEFECTS DUE TO FUNGI

Stain: This happens when fungi consume only the sapwood, rather than the more nutritious heartwood. It does not affect heartwood because it does not include food ingredients. The colouring effect of a stain does not diminish the wood's durability.

This problem is caused by decay, which is caused by wood-eating or wood-destroying fungi. To put it another way, these fungi degrade cells. Sapwood and heartwood are equally vulnerable to their effects. There is a notable weakening in strength.

DEFECTS DUE TO INSECTS

Wood-eating insects, such as beetles, termites, and marine boars, weaken wood by eating it and boring holes in it. Little creatures called beetles bore holes in nearly all kinds of sapwood. Larvae bore into the sapwood from all sides, reducing it to powder. Colonies of termites are common.

They can chew wood and create tunnels through it at a rapid rate. Termites can weaken most woods, but there are select ones that are resistant. Saltwater is home to marine boars. They often construct underground tunnels out of wood when seeking safety. This bug can damage any kind of wood or timber.

DEFECTS DUE TO NATURAL FORCES

Knots are the most typical flaws brought on by the elements. As a tree matures, its lower branches and trunk eventually rot and die. Those limbs' bases stay put in the trees as they expand. Knots, a defect, could be caused by these foundations.

Two distinct varieties of knots exist.

Dried-out remnants of broken branches, known as "dead knots," can be easily broken off. Healthy knots hold together well and soundly. If minor, they shouldn't be too much of a bother. Because they are still linked to the wood, live knots are rarely a problem.

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However, in dead knots, they are not securely fastened, hence decreasing the strength. The structural value of wood is reduced because of knots because of the reduction in strength. When the load is applied perpendicular to the grains, knots become severe flaws.

Timber with a twist has its two ends rotated in opposite directions, creating a new shape. The strong wind is primarily to blame for this flaw since it causes the trees to twist.

Shakes are natural flaws in wood that typically appear near the timber's yearly ring or growth ring. What we mean when we say "shakes" is a split or crack in the wood. Depending on the depth and function, this may or may not be a structural issue.

Aesthetics are the primary concern. In settings where first impressions matter, trembling is not welcome.

There are primarily three types of shakes, and they are as follows:

With star shakes, the shaking begins at the bark and moves inward toward the sapwood and possibly the heartwood along the medullary rays.

Cracks are more prominent on the bark's outside edge and narrower on the inner side (usually sapwood, sometimes heartwood). Extreme heat or cold during tree growth and quick or uneven seasoning after timber is cut are the primary causes of star shakes.

The temperature differential produces the shrinking that forms the crack, which in turn is caused by extreme heat or cold. The annual growth ring can be used to predict the timing of cup and/or ring tremors. It might split the growth ring in two or all the way through. Ring shaking occurs when the fissure entirely splits the yearly ring.

In other words, all cup shapes are also ring shapes, but not all ring shapes are cup shapes. The primary cause of this type of crack is intense frost action. In contrast to star shakes, which spread outward from the sapwood toward the pith, heart shakes begin in the pith and travel along the medullary rays. This split is due to internal shrinkage of the wood.

An abnormal growth known as a rind gall can be defined as an overgrowth of bark. Consequently, rind galls are used to describe abnormal growths on the bark of trees. This aberrant expansion is due to careless branch trimming. The wood from these trees is weak and unsightly. Dents,  Gouges Dents and gouges in varied wood show that the tree was subjected to crushing or compression. The main causes of this problem are improper tree falling and strong winds when the tree is still young.

Impact in Timber

Bowing in Timber:

The bow is a flaw in the lumber that manifests as a curve running parallel to the length of the board.

Cup in Timber:

The cup is a flaw in the wood that manifests as a kink in the cross-grain direction.

Check-in Timber:

A check is a fracture in wood that develops as a result of the seasoning process and has the effect of tearing apart the wood's fibre layer.

Split in Timber:

The term "split" is used to describe a wood log that has a check that runs from one end to the other. Splits are lengthwise separations of the wood due to improper handling or seasoning.

Twist Wood Defect:

A twist is a helical distortion down the length of a timber piece.

Honey Combing in Timber:

Internal strains in the wood emerge in the form of numerous circular and radial cracks when it dries. Honey-combing is a flaw that occurs when the inner layer of wood takes on a honeycomb texture.

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