Chemical Delignification: Its Causes and Effect on Your Home
When most people think of timber pests, the term tends to call to mind images of termites, wood borers, and other creatures that pose a serious risk to the structural integrity of their homes. Throughout Perth and other areas of Western Australia, those timber-threatening species require constant vigilance. Many people, however, forget that there are other types of timber pests that can threaten their home – and not all of these dangers spend their time scurrying around on tiny little legs. Chemical processes can also be real pests when it comes to home. Take, for example, the timber-destroying process known as chemical delignification.
What is Chemical Delignification?
Chances are that you may have heard of this dangerous timber pest, even if you haven’t heard the term “chemical delignification.” At one time, it used to be commonly referred to as defibrosis, and was also commonly known as “hairy timber.” Both of those terms described the appearance left behind by this chemical process. For the last several decades, however, this pest has been described in a way that more accurately depicts its true effects on timber.
To understand this process, it is helpful to understand the nature of lignin, since it is this substance that chemical delignification assaults. Lignin is classified as an organic polymer that is found in the tissues of plants and certain varieties of algae. These polymers are essential for the formation of timber cellular walls, since it fills the spaces within a plant’s cell walls, providing needed rigidity and strength. Some tree species contain more lignin than others, which is one of the reasons why different types of trees offer varying levels of rigidity.
For these and other reasons, lignin is sometimes referred to as the bond that cements wood fibers together. Its role is thus essential for any timber’s structural integrity. The problem is that, like every other timber component, it is anything but indestructible. It can be destroyed by fungi, insects, and the elements. As you’ll soon learn, chemical reactions are also a major threat to this integral timber component.
What Delignification Looks Like
There is a good chance that you have personally seen wood that has experienced delignification. The effects are noticeable even to the naked eye, and include the appearance of hairiness on the exterior of the wood. This is the result of lignin being destroyed or damaged, which in turn causes the timber fibers to separate from one another. That creates a frayed appearance that resembles hair on the timber surface. Timber that suffers from this deterioration loses its structural integrity over time, just as it would if it were suffering from a termite or other insect pest infestation.
What Causes Chemical Delignification?
There are certain locations where this process is more likely to occur: around areas where salt water is common, and locations near industrial areas or heavy traffic. These areas offer everything that this chemical process needs to attack and destroy timber. Seaside regions are susceptible to this pest due to the way in which air carries salt to the timber. Those winds can carry this salt five or more kilometers into the interior of an area, where it settles down onto building tops, and eventually makes contact with tiles and roof battens. That salt can initiate the delignification process.
Of course, salt in the air might have been the most pressing concern centuries ago, but there is an even more pressing danger in the modern age: industrialization. Chemical factories and many other industrial facilities release compounds into the surrounding air that, like salt from the sea, get carried by the wind only to eventually settle on rooftops. At the same time, many vehicles produce pollutants that carry chemical traces that follow that same pattern of behavior. These chemicals can create the same type of delignification effect, causing incredible damage to the timber that humans use to construct homes, garages, and other structures.
Now, this process does not occur overnight. In fact, even after it has taken root within a building’s structure, the visible effects often go unnoticed for many years. Prolonged exposure to salty air and pollutant chemicals weakens lignin over time, fraying the bonds that hold timber fibers together, and eventually creating structural weaknesses that can be catastrophically expensive to repair. Often times, the presence of chemical delignification is not recognized until that serious damage has already occurred, since relatively few people have their homes and other structures regularly inspected for this phenomenon.
An Ounce of Protection
As noted, the chemical delignification process can be devastating to structures where it takes root. Over time, timber not only frays on the outside – ruining the exterior appearance of any structure affected by the process, but deteriorates on the inside as well. That weakens the wood, reducing structural integrity and timber strength. When it occurs on the roof of a home or other structure, it can lead to an array of complications ranging from leaks to outright collapse.
In many instances, the only real solution that can address serious delignification is replacement of the affected timber. While there are instances in which the process can be stopped if it is caught early, once it has progressed to the point where the timber’s structural integrity has been compromised the damage is already done. Obviously, there is no way to magically restore wood strength and integrity once it has been lost.
When caught early, however, there are several ways to mitigate additional damage to the timber. Professional sealing of the timber can block the salt or chemical pollutants from making contact with the exterior of the wood, and disrupt their ability to get to the lignin. A thorough paint job can accomplish the same effects, provided that it is regularly maintained. The timber can also be oiled to block chemical contaminants from starting this process.
Given those facts, the most obvious and preferred solution is to prevent the problem from occurring in the first place. With most new buildings, this is rarely an issue. Today’s construction techniques typically take these dangers into consideration, and prepare the timber that will be used for frames, roofing, and other elements of a home. Even so, it is wise to have an inspection prior to purchasing even a new home, just to ensure that no corners have been cut during this prevention process.
Resolving the Problem
Unfortunately, there is no easy way to get around this issue. When delignification occurs, homeowners have only one real option: call in the professionals. Unless you are prepared to completely rebuild whole sections of your home – or in some instances, the entire structure – something needs to be done about the chemical process that is destroying your home’s integrity. The only way to ensure that your solution is properly implemented is to have it done by someone who understands the issue completely.
That care begins with a thorough inspection to determine the extent of the problem. While homeowners might initially notice some fraying of the wood fibers on the exterior of their structures, they are less likely to see the internal destruction that goes on throughout the timber. That structural integrity weakness is the real danger posed by this chemical attack, since it can make the roof and other areas of the home less safe over time. A competent inspector can identify the presence of this pesky problem, evaluate its current impact on the structure, and determine whether anything is salvageable.
As discussed earlier, affected timber can be treated in the very early stages of the deterioration. Oils, sealants, and paint can be applied to prevent the chemical effect from spreading to the remainder of any wood, provided that the loss of fiber cohesiveness has not already taken root in a large portion of the affected area. This sealing process provides an impenetrable barrier to keep chemicals in the air from making contact with the wood and its lignin.
In cases where the impact is already severe, it is unlikely that such inhibiting measures will be effective. Once the chemical process has worked its way beneath the surface of the wood, no exterior solutions can reverse or halt the process. At that point, the only solution is to determine the exact extent of the damage and identify all of the timber that has been affected by the devastations. Every piece of wood that is suffering these effects will need to be replaced if the home’s integrity is to be restored. At times, that may involve only a small section of the house. In more severe cases, however, this infestation may necessitate major reconstruction efforts to rid the home of the problem.
It’s easy to forget that your home’s structure faces many dangers that don’t involve fire, water, insects, and other natural disasters. That can cause many homeowners to ignore the impact of other environmental factors, especially unseen elements floating in the wind. If you live in a high risk area in or around Perth, you need to be cognizant of how airborne salt and other chemicals could be stealthily assaulting your home’s integrity and take action to ensure that your property is protected from chemical delignification.