NASH TIMBERS NEWSLETTER SEPTEMBER 2009

NASH TIMBERS SEPTEMBER NEWSLETTER

Many thanks for the wonderful response I have received from my newsletter I really appreciate the feedback.

The Timber presentations were heavily supported by our clients, it is nice to be able to meet the face behind the voice.

Nash Timbers continue with The Nash Timber Presentation which has been certified by NSW Architectural Board for CPE Activity Formal Points & Builders CPD Event, at our home office monthly.(2 formal Points)

SPOTS STILL AVAILABLE FOR, ALL PRESENTATIONS

When: 23/9/09, 21/10/08 and 25/11/09/At: 5:00pm to 6pm

Venue: 136 OLD SOUTH HEAD ROAD VAUCLUSE (MUST BOOK)

Nash Timbers Regular feature.

1) F.A.Q

2) PROBLEMS THAT ARISE

Send your question and test our knowledge!!!!!

F.A.Q

Can a Chain Of Custody be given for Recycled timber?

YES, THIS MEETS THE REQIREMENT FOR GREEN STAR DEVELOPMENTS.

OOPS!

“Why has my recycled Flooring bowed?” Asked the builder, “I thought Recycled Flooring was the most stable timber due to its age.”

All timber Recycled and New must be dried correctly or the floor board will have uneven shrinkage.

RECYCLED TIMBER

Interim Industry Standard Recycled Timber

FOREST WOOD AUSTRALIA

Recycled Timber Interim Grading Rules

(extracts from the above interim report)

Interim rules for visual grading of recycled hardwood timber for structural and decorative uses have just been released. Based on the AS 2082 hardwood grading rules with the additional characteristics of bolt, screw and nail holes as well as notches, and more importantly the previous load history and duration of load (DoL) effects that recycled timber has been subjected to over its previous use history. 

Testing and analysis of recycled timber by the University of Technology Sydney has confirmed that the structural properties of nominally sound recycled timber are not the same as "new" timber, with short term strength about one to two "F" grades below those assigned to "new" timber. However, it was also found that the stiffness for recycled timber did not vary significantly from that of "new" timber, so where stiffness dictates design and use, there will be less impact. For the efficient utilisation of recycled timber for structural purposes development of special span tables is being undertaken and will be completed by the end of 2008. 

The decorative grading rules are an attempt to better resolve customer / industry expectations about the visual appearance of recycled products. 

The rules are interim as they have to be trialed over the next 12-24 months before further development into an Australian Standard. Copies of the Interim Standard can be downloaded for free fromwww.timber.org.au by clicking on Design & Construction/Technical References.

2.5 GRADE LIMITATION AND GRADING

2.5.1 Basis

Grading to the recycled grades in this Standard is based on assessing the characteristic or group of characteristics within a piece, which is considered to have the greatest limiting effect on the grade of that piece, when assessed in accordance with the grading rules. Each piece shall be inspected on all surfaces and the ends.

2.5.2 Limitations

The grade descriptions in Section 3 provide limitations on all characteristics known to have a significant effect on strength and describe material on the lower limit of that grade. Each parcel of small end-section timber used instructural applications shall contain a range of material such that not all of the material is near the lower limits of the grade.

2.5.3 Variations in assessment

Within any parcel a maximum variation of 5 percent between the grading of pieces by individual inspectors or graders shall be acceptable, provided that none of the pieces in the disputed 5 percent shall have characteristics that exceed the maximum allowed in the grade by more than 10 percent.

2.5.4 Re-sawing and dressing

If the cross-section of the piece of timber is reduced by longitudinal sawing or dressing after the initial assignment of a recycled grade, the original grading is nullified.

2.5.5 Docking of multiple lengths

When grading a piece of timber that is to be supplied as a multiple of a shorter ordered length it shall be graded as if it were in the shorter length.

2.5.6 Moisture content of preservative treated timber

Where timber is seasoned and subsequently preservative treated, the preservative treatment process may increase the moisture content

of timber considerably. Unless such timber is re-dried (low temperature) to the moisture content range for seasoned timber it does not conform to the requirements of this Standard for seasoned timber.

2.5.7 Grading check

A check of the grading of the timber may be required some time after the grading undertaken by the producer or supplier. Where the purpose

of the check is to estimate the accuracy of the previous grading, reasonable allowance shall be made for changes in characteristics of the timber

that are the result of moisture change. These changes in characteristics may include but are not limited to:–

(a) reduction in dimensions (shrinkage);

(b) increase in distortion (bow, spring, twist and cup);

(c) increase in, or development of, seasoning checks, splits, end splits and shakes;

(d) increase in, or development of, loose gum veins.

2.6 SAPWOOD SUSCEPTIBLE TO LYCTID BORERS

The method for detection of Lyctid-susceptible sapwood shall be as given in AS 1604.

NOTE : Refer to Appendix A for the susceptibility of species and

note that some states (Qld and NSW) limit the sale and use of Lyctid-susceptible timber.

2.7 PRESERVATIVE TREATMENT

When structural timber graded in accordance with this Standard is preservative treated, treatment shall be in accordance with AS 1604.1.

2.8 IDENTIFICATION

Where a parcel or member is graded as complying with this Standard, the following details shall be clearly stated on the invoice:–

(a) The name of this Standard

(b) The grade

(c) The species or that mixed species have been supplied

(d) The durability class if applicable

(e) If graded as seasoned, the word ‘SEASONED’

The report summarises the acceptable level of permissible characteristics in recycled timber.

The reports discusses types of characteristics as below:

Knots (A section of a branch that is embedded in the wood of a tree trunk).

Borer holes, (A small hole in timber caused by the larval or adult stage of a wood boring insect.)

Nail, screw, spike and bolt holes (Mechanical damage in the form of a cylindrical hole.)

Notches (A loss of solid wood through the cross section of a member usually in the shape of rectangular prism.)

Termite Galleries (An irregularly shaped passage or burrow excavated bt termites in the bark or wood. An enclosed termite gallery is one that is not completely open to visual inspection throughout its entire length.)

Slope of grain

Sound heart and heart shakes (A partial or complete dislocation, breakage or longitudinal separations of wood fibres due to causes other than drying.Heart shake extends from the pith of a tree)

Gum veins, ( A ribbon of gum between growth rings that may be bridged radially at short intervals by wood tissue)

Ring shakes and included in bark (a shake following a growth ring)

Gum Pockets, (A cavity that contains or has contained gum.)

End Splitting (A split at the end of a long piece.)

Checking- (Separation of fibres radially across growth rings and along the grain forming a fissure. i.e End Check and heart check. A surface checks depth not exceeding ten percent of the thickness of the piece of timber.)

Rot.

Sapwood, (the outer layers of the wood of a tree, when the tree was living)

Wane, (the presence of the original underbark surface with or without bark)

Want (the absence of wood, other than wane)

Twist, (A spiral distortion along the length of a piece of timber)

Pipe, (A longitudinal cavity along the growth centre of round timber)

Lyctid- susceptible sapwood (lyctine beetles have embedded into)

Bow, (A deviation in the longitudinal direction of the piece causing the face to curve away from its intended flat plane.)

MONTHLY SPECIAL (WHILE STOCKS LAST)

SELECT GRADE BLACKBUTT 80MM X 19MM FLOORING @ $66.80 SQM PLUS GST

SELECT GRADE BLACKBUTT 130MM X 19MM FLOORING @ $73.00 SQM PLUS GST

Nash Timbers

PO BOX 163
VAUCLUSE NSW 2030

Telephone: (02) 9337 6800
Facsimile: (02) 9337 1595

Email: info@nashtimbers.com.au
Web: http://www.nashtimbers.com.au/

Showrooms (by appointment only)

ECOLOGICALLY SUSTAINABLE

FOREST MANAGEMENT

ENSURES THAT THE FOREST STRUCTURE AND

HABITATS ARE MAINTAINED.

NEXT MONTH MILL CLOSURES AND HOW IT AFFECTS THE END USER