In The Lakes , Chemical delignification is a very common problem that often goes undetected. It will generally be detected on a building and pest inspection when a home is being sold or in the course of a timber pest treatment. If chemical delignification is identified on a pre-purchase building inspection it can make or break the deal. That is where the chemical delignification specialists come to the rescue.
Powerdrive roofing have been working closely together with many building inspectors in The Lakes and across Perth for many years and have now made the move Australia wide.
In 2006 a treatment was perfected using a timber hardening chemical to re strengthen the timber and regain the structural integrity in your roof timbers.
Weather it is for the sale to go ahead or just for your own peace of mind. Powerdrive roofing should top the list of people to call when it comes to the treatment of chemical delignification treament in Perth.
We offer friendly and affordable pricing, starting from as little as $20.00 per sqm for basic sand and seal of battens to $25.00 Per sqm for complete chemical delignification treatment (includes rafters) this will also depend on severity.
What is chemical delignification
Lignin is an organic natural ‘glue’ that holds the cells which make up the timber component together. The phrase Chemical delignification is when the lignin within the timber is destroyed and force to penatrate the external barrier of the timber, as the timber gradually weakens and finally collapses when the timber becomes defibrated. This type of timber deterioration was commonly referred to as ‘hairy timber’ as the fibres within the timber detach once the lignin is broken down. It is now better and more commonly known as Chemical delignification.
What causes chemical delignification?
As suggested by the name of this type of timber deterioration, chemical delignification can be caused by some form of airborne attack on the timber.
Examples of causes include:
In areas close to the sea, airborne salts attack the timber. This process is accelerated for homes with terracotta roof tiles, as any tile fretting will allow further amounts of contaminated moisture into the roof loft space. It is also a theory that the terracotta type roof tiles curing on the roof can contribute to the Chemical delignification and accelerate the process.
It is believed areas of high pollution, such as homes in close proximity to industrial areas or main roads, airborne pollutants will cause chemical delignification. However, more and more homes in the Perth hills and surrounding suburbs are being found to have advanced cases of chemical delignification.
Another cause of chemical delignification is the release of gases into the roof void space. This may include the escape of gases from appliances such as slow combustion stoves or perforations to ducting from flued gas appliances.
Hot water systems located within the roof loft space may also accelerate chemical delignification.
Where Will I Find Chemical Delignification? Is Chemical Delignification a Structural Problem?
Chemical delignification is generally a problem associated with timber roof battens when identified within the roof void space whilst conducting a pre-purchase building inspection. Although Chemical delignification has the potential to affect other timbers within the roof void space, generally due to the sectional size of the roof battens accompanied with their position within the roof void space, they are the first to suffer the effects of this chemical reaction. If for instance a timber-framed roof had timber battens & a roof tiled covering, it would be fair to assume that a roof collapse would occur prior to any significant delignification occurring to any structural framing members. Therefore, making the tile battens themselves a structure issue if found to contain Chemical delignification.
Although chemical delignification has been associated to timbers with poor durability properties such as Douglas fir (Oregon), here in Perth we have witnessed firsthand that chemical delignification can occur to reasonably durable timbers such as Jarrah. Generally speaking, Jarrah has an above ground durability rating of 15-40 years, therefore making many Perth homes susceptible to this risk of infestation.
Although chemical delignification takes a number of years before collapse occurs, it should be identified and classified as a major defect whilst conducting a pre-purchase building inspection. Furthermore, it is not recommended to walk on any roof cover when Chemical delignification is identified, due to the threat of the roof cover collapsing.
It would also be prudent to consider the cause of the chemical delignification, as the cause may have bearing on the future health of occupants.
Is chemical delignification a timber pest
In short, yes, it is.
Chemical delignification much like termites and other timber pests, chemical delignification attacks the timber and weakens it from the inside out, this will leave the “hairy timber” appearance on the external face of the batten and once sanded can give the misconception that it is all fine and back to normal, but internally the structure is extremely compromised and weakened.
Chemical delignification is classed both as a timber pest and as a major structural defect and should be treated as a matter urgency.