Defect yes or no?

Hairy timber, fluffy batten, or furry batten. We see these from time to time when conducting pre-purchase building inspections in Perth. The technical term to describe these hairy timbers is a process known as ‘Chemical Delignification’. Chemical Delignification can occur to timber roof battens and other roof timbers and is generally visible from within the roof void.

We were asked to do an invasive inspection from a concerned client due to chemical delignification being identified in their roof void by a building inspector. The building inspector reported that the delignification to the roof tile battens was a major structural defect, and a safety hazard. Furthermore, our client was told not to walk on their roof for risk of it “caving in”.

Here is the video of what we found:

Flagging the roof tiles as a safety hazard was a valid comment by the previous inspector as the tiles observed from within the roof void were deteriorating, but as you can see from the video the roof is not going to “cave in” due to the delignification to the roof tile battens.

What is Chemical Delignification?

Lignin is the natural glue that holds the fibres of wood together. When the Lignin is broken down the fibres then detach from each other creating a visible hairy surface to a section of the timber.

Chemical Delignification of roof tile battens are typically associated with Terracotta Roof tiles that have been in service around 50 + years, sometimes less. We have found homes located near the ocean, industrial areas, or major roads that have heavy traffic can be affected. We have found terracotta tiled roofs are more prone to delignification due to the porosity of the tiles which subjects the tile battens to a wetting and drying cycle which breaks down the Lignin.

At 50 + years old Terracotta Roof Tiles in most cases have reached the end of their service life. They become brittle, the back edge of some tiles are generally fretting way, which makes them susceptible to leaking.

In respect to Delignification of Roof Tile Battens, generally the affected layer it is usually only very thin. Because the surface fluffs up, it looks a lot worse than the 0.2 mm or so in depth that is affected.

Other than extreme cases, in our experience, delignification does not appear to change the properties of the unaffected timber, simply reduces the cross section a very small amount. Tile battens are installed as unseasoned timber. Any reduction in strength due to the reduced cross section is more than offset by the increase in strength over time as the originally unseasoned battens have dried in service.

The Australian Standard 4349.3 – 2010 Inspection of Buildings Part 3 Timber Pest Inspection does not classify delignification as a timber pest.

A Pre-Purchase Building Inspection is a visual or non-invasive inspection, which means scrapping roofing timber and battens affected by delignification is outside the scope of an inspection completed in accordance with Australian Standard 4349.1.

What to do!

If you are buying a home with a tiled roof, we recommend buyers insert a special condition to protect their rights should there be an issue, as the Standard REIWA Building Inspection Condition dated Oct 2019 excludes the Roof Cover.

If we can help with an invasive inspection to investigate and report on the seriousness of Chemical Delignification feel free to get in touch with us on 0420 803 292 or [email protected].

 

Why is unauthorised building work an issue?

Did you know that if damage or injury caused by unauthorized building work then the home owner is legally liable? And they are unlikely to be covered by their insurance. Local councils can order home owners to have unauthorized building works rectified.   They can even have unauthorized structures demolished. Having unauthorised building works can adversely affect the marketability and value of the home.

Many established Perth homes have had alterations and/or additions (building works) completed to improve the look and amenity of the home. For example, a patio or pergola, a new garden shed, a retaining wall may have been added. Or maybe a garage has been converted into a fourth bedroom.

In most instances, building works require approval by the local council. Once approved, the local council will issue a building permit.  This is required prior to any works commencing.

The building permit will stipulate all the conditions to be met by the person completing the works. The conditions will include planning and building regulations which are designed to protect the home owner, occupants and also not adversely impact on neighbouring properties.

What is unauthorised building work?

Unauthorised building work may include building work completed without a building permit, or building works that have not been built in accordance with the approved plans and specifications.

Retrospective Approvals for unauthorised building work.

Local governments are able to issue a ‘building approval certificate’ to the applicant in relation to unauthorised building work.

The applicant will need to complete all forms, submit adequate plans and specifications (documentation).  They will also need to pay all relevant fees and demonstrate that the building work complies with the relevant standards.

Some councils have differing standards in regards to the documentation required. Documentation will need to be provided by most, if not all, of the following consultants.

• Building Consultant / Project Manager
• Architectural draftsperson
• Structural Engineer
• Building Surveyor / Private Certifier
• Energy efficiency report
• Surveyor
• Bush Fire Attack Level report
• Registered builder / qualified tradespeople.

The quality of the documentation will dramatically impact the success of the application and time taken for approval.

Providing an approval of this nature retrospectively allows local governments to be satisfied that building works are safe, complies with all requirements, and is included in their building records.

If you are concerned that a building or incidental structure on a property you own or are thinking about purchasing, may not have the necessary approval, contact the relevant local council to confirm what building approvals have been granted.

No fuss / fast retrospective approvals

Home Integrity will carry out a full site investigation for structural adequacy and compliance with planning and building codes.

This inspection is carried out by a registered builder, who understands the retrospective approval system, and is experienced in having approvals granted fast.

Home Integrity will complete all forms, liaise with the local council and collate all documentation required from our team of qualified consultants.

Home Integrity will project manage all phases from documentation to application, to ensure the approval is granted as fast as possible.

To book your initial inspection and report click here.