Step by Step Malay Timb

8/8/2019 Step by Step Malay Timb

1/19


2/19

2

2


3/19

3

STEP 1:SO YOU WANT TO USE TIMBER

Basically, you want timber or mainly two purposes, i.e., or structural uses; and

aesthetic purposes (e.g., urniture and other decorative uses).

I you are looking or structural timbers, then go to Step 2 .

I you are looking or timbers or decorative purposes, then skip to Step 4 .


4/19


5/19

5

By reerring toAppendix 2 , speciy the species o your choice (i you decide to usesingle

species) or the correct Strength Group (i you decide to use the

End-Use groupingconcept).

Decide whether you wish to use single species or End-Use groups

Now skip to Step 5 .

STEP 3: SPECIFIC TIMBERS VS. END-USE GROUPS

There is a question o whether you wish

to recommend a specic timber or the

job in hand (e.g., Kapur or roo trusses),

or a mix o timbers, each capable oullling your needs. The advantage

o choosing a single species is that

consistency is assured (or as assured as

timbers can be). Balanced against this is

that speciying single species will tend to

exhaust the species quickly and drive up

the price o that particular species. Also,

this is inecient utilisation o the orest

resource.

Thereore, as ar as possible, try to speciy

timbers that are capable o doing the

job as an End-Use group. The timbers in

each End-Use group have been screened

or their properties vis--vis the job in

hand. Thereore, it does not matter i any

one o the group members is supplied or

a mixture o members is supplied, as each one o them is capable o doing the job.

Speciying End-Use groups will bring down the cost o the project as now the supplier can supply a

mixture o species in lieu o the more expensive timbers. There will be less delay too, or now the suppliers

can make up the supply with a mixture o species instead o waiting to collect enough quantity o a

particular species or delivery. End-Use groups or the more common usage o timber have been compiled

by the Forest Research Institute Malaysia, and urther inormation on these End-Use groups can be

obtained rom them or the Malaysian Timber Council.

Ater determining the strength requirement o your application, you can now decide on the

timber you need by reerring to Appendix 2.


6/19

66


7/19

7

STEP 4: TIMBERS FOR DECORATIVE PURPOSES

Speciying timbers or aesthetic purposes is very much an

individuals choice, dictated by taste and artistic inclinations.

Timbers are selected based on their decorative characteristics.

However, it must be noted that considerations must be given to

aspects such as colour matching; nishing and natural deects.

Very oten, your choice is limited to a ew truly decorative timbers,

and the specications are thereore species-oriented.

Go to Step 5 .

Speciy timbers that have the decorative

characteristics that you want.

Include a clause on colour consistency

(or stained to give a uniorm colour).

Speciy the fnishing you want, e.g., planed; moulded;

coated with plastic; special fnishes (speciy type o paints i

necessary).


8/19

88

STEP 5: DURABILITY

CONSIDERATIONS

Decide whether you need durability or not,

based on the hazard that the structure is

expected to ace during service.

I you do, go to Step 6 .

I you do not need durability,

then skip to Step 9 .

Timber is subject to attacks by biological agencies

such as ungi and insects, especially termites.

While some timbers are more durable than others,by and large, all timbers will succumb to attacks

under the right conditions. These conditions

include the presence o moisture, and insect

inestation, especially the possible presence

o termites. The conditions under which your

structure is installed will dictate the amount o

hazard that the timber will ace during service.

I your application is expected to last, then

durability becomes an important consideration.The choice then is to either use naturally

durable timbers or, i they are not available (or

too expensive), have the timbers treated with

preservatives.


9/19

9

STEP 6: HAZARD TYPES

Reer to Appendix 3 to decide whichhazardtype applies to your applicationGo to Step 7 .

The hazard aced by timber in service varies in accordance with the degree o

activities o the wood destroying agencies. For instance, timber under cover

will ace less hazard than timber exposed to the elements. The various service

conditions have been grouped or their degree o severity in terms o hazard

aced by timber in service. The hazard types are described in the table ound

in Appendix 3.


10/19

1010


11/19

11

Decide whether you require preservative treatment

or your timber. I you do, go to

Step 8 , i not, skip to Step 9 .

Reer to Appendix 2 or timbers requiring

preservative treatment.

STEP 7: NATURAL DURABILITY VS ARTIFICIAL DURABILITY

As mentioned in Step 5 earlier, timber varies in its resistance

to attacks by biological agencies. Some species are more

durable than others. In act, some timbers are so durable, that

they do not need any preservative treatment, e.g., Teak andBalau. However, other than this handul o naturally durable

timbers, all other timbers should be treated with preservatives

to enhance their service lie-span.


12/19

12

Add a clause requiring pressure

impregnation methods or treating

your timber.

There are many chemicals available in the market that are used to protect timber.However, or a timber structure to be properly protected, the treatment should

last or a long time and i possible, permanently. The only way to achieve this is to

select chemicals that are capable o permeating into the timber in a permanent

manner. Furthermore, many o the chemicals available in the market tend to

break down with time and thereore their protection value will reduce as time

goes on.

The most widely used preservative chemical or timber in the world today is CCA,

which is short or a mix o water-borne inorganic salts o Copper, Chromium,

and Arsenic. CCA is perect in that when impregnated into the wood, it is chemically bonded onto

the wood matrix and thereore will not leach out o the wood, imparting a permanent protection to the

timber. Commercially, CCA is pressure-impregnated into the timber. The down side o using CCA is

that it is considered as environmentally unriendly by many countries. Various substitutes have been

developed to replace CCA but none o them has proven to be as ecacious as CCA.

Another pressure-impregnation method available is LOSP (Light Organic Solvent Preservatives). This

method uses a mixture o solvent-borne chemicals (usually an organo-tin and an insecticide).

Both methods have their advantages and disadvantages, and the choice is very much dependent onthe needs o the application. Table 1 lists out the comparative characteristics o CCA and LOSP.

The preservative loading required varies with the degree o hazard to which the timber is exposed.

Obviously, the greater the hazard, the greater the amount o preservatives needed. Appendix 4 lists out

the preservative loading required or the various hazard classes.

STEP 8: PRESERVATIVE TREATMENT

Preservatives are chemicals that are introduced into the timber to prevent

attacks by biological agencies. In order to ensure proper protection o the

timber, the chemicals must be well and truly impregnated into the timber. The

only way to ensure this is to use pressure-impregnation methods when treating

timbers. Merely brushing, spraying and dipping the timber with preservatives willnot impart an ecient protection to the timber. Thereore, it is wise to insist on

the pressure-impregnation method when treating your timber.


13/19

13

Speciy the preservative loading required

or your application, with reerence to

Appendix 3 .

Table 1: Comparison between CCA and LOSP

Go to Step 9 .

Please note that LOSP is not recommended or applications that are in contact with the ground.

CHARACTERISTICS CCA LOSP REMARKS

SOLVENT WATER WHITE SPIRIT THE WATER IN CCA WILL WET THE TIMBER

AND THUS SUBJECT THE TIMBER TO

DIMENSIONAL MOVEMENT UPON DRYING,

WHILE LOSP WILL NOT WET THE TIMBER AS IT

HAS NO WATER.

COLOUR GREEN COLOURLESS CCA WILL IMPART A GREEN COLOUR TO THE

TREATED TIMBER, WHILE LOSP ALLOWS THE

ORIGINAL COLOUR OF THE TIMBER TO SHOW

THROUGH.

FIXING METHOD CHEMICALLY BONDED TO NOT CHEMICALLY BONDED, CCA AFFORDS A MORE PERMANENT

THE CELL WALLS OF THE AND CAN BE LEACHED OUT OF BONDING WITH THE WOOD. LOSP TENDS

WOOD. THE WOOD. TO LEACH OUT OF THE TIMBER,

ESPECIALLY WHEN IN CONTACT WITH THE

GROUND.

EFFECTIVENESS EFFECTIVE AGAINST VERY NOT SUITABLE FOR TIMBERS IN CCA IS A BETTER CHOICE FOR OUTDOORS

HAZARDOUS CONDITIONS CONTACT WITH THE GROUND. APPLICATION.

EFFECT ON METAL MILD CORROSIVE EFFECT ON NO EFFECT ON METAL. CARE SHOULD BE TAKEN WHEN USING CCA

FASTENERS METAL FASTENERS WHEN IN WET OR HUMID ENVIRONMENT.

WET OR UNDER HUMID

CONDITIONS.


14/19

1414


15/19

15

As wood is a hygroscopic material, it will absorb and/or give up moisture to the surrounding atmosphere

to achieve a moisture equilibrium. During the process o absorbing and losing water, the wood will swell

and shrink, causing dimensional changes that may compromise the structure. For example, foor boards

that are installed wet will shrink upon drying and you will nd gaps between the boards. On the otherhand, swelling will cause stuck drawers and sticky doors. In principle, it is advisable to have the timber

at the approximate moisture content as the ambient environment in which it is installed to prevent any

dimensional movement.

As a guideline, the moisture content o the outdoor environment in Malaysia is approximately 19% while

in an air-conditioned room, the m-c drops down to around 12%. It ollows that wood that has been dried

by leaving it exposed to the outside environment,

will not be drier than 19% m-c, no matter how long

it is let there. I and when such timber is installed

in an air-conditioned room, the wood begins todry out and in the process will shrink and develop

dimensional movement.

I your application is outdoors and exposed to

the elements, then it is perectly sae to use

wet timbers. However, i the job is within an air-

conditioned environment, then it is advisable to use

timber that has been dried down to approximately

12%. And the only way to dry timber down tolower than 19% is to dry it articially in a kiln,

hence, kiln-dried timber.

STEP 9: MOISTURE CONTENT

Reer to Appendix 4 or the m-c o

timber required or various applications.

Add a clause on having your timber kilndried i your application is exposed to

air-conditioned environment.

You should by now have covered the most

important aspects of specifying timbers for

your project. If you have any further queries

on the use of timber, please contact the

Timber Industries Development Division ofthe Malaysian Timber Council at

[email protected]


16/19

Appendix 1: Strength Groups o Timbers and Their Applications

APPLICATION STRENGTH GROUP* STRENGTH GROUP**

Structural Components

i. COLUMNS, BEAMS, BEARERS, STUDS, JOIST, TIES & STRUTS A & B SG1, SG2, SG3 & SG4

ii. FORM WORK A, B & C SG1, SG2, SG3, SG4 & SG5

Roofng

i. RAFTERS, TIES, STRUTS, PURLINS & BRACING A & B SG1, SG2, SG3 & SG4

ii. BATTENS A, B & C SG1, SG2, SG3, SG4 & SG5

Staircase

i. STRINGERS, TREADS, TRIMMER BEAM & HANDRAIL A & B SG1, SG2, SG3 & SG4

ii. BALUSTRADES A, B & C SG1, SG2, SG3, SG4, SG5 & SG6

Flooring

i. FLOOR BOARDING & PARQUETRY A & B SG1, SG2, SG3, SG4 & SG5

ii. SKIRTINGS A, B & C SG1, SG2, SG3, SG4, SG5 & SG6

Walling

i. WALL, PARTITION, FRAMING & EXTERNAL WALL BOARDING A, B & C SG1, SG2, SG3, SG4, SG5 & SG6

ii. INTERNAL WALL BOARDING, SLATE SCREENS A, B, C & D SG1, SG2, SG3, SG4, SG5, SG6 & SG7

iii. FACIA BOARDS A & B SG1, SG2, SG3 & SG4

Ceiling Frames

i. COVER BATTENS TO JOINT OF CEILING SHEETS A & B SG1, SG2, SG3 & SG4ii. CEILING STRIPS AND SOFFIT BATTENS A, B & C SG1, SG2, SG3, SG4, SG5 & SG6

Door & Window Frames

i. DOOR, WINDOW AND VENT FRAMES, INCLUDING THEIR STOPS AND GROUNDS A & B SG1, SG2, SG3 & SG4

ii. DOOR LEAVES, WINDOW AND VENT SASHES A, B & C SG1, SG2, SG3, SG4, SG5 & SG6

Furniture

i. BUILT-IN FITTINGS, FURNITURE GENERALLY AND WORKSHOP FURNITURE A, B & C SG1, SG2, SG3, SG4, SG5 & SG6

ii. SCIENCE LABORATORY TOPS A & B SG1, SG2, SG3 & SG4

Beading Fillets & Edgings Generally A, B & C SG1, SG2, SG3, SG4, SG5 & SG6

* The strength groups mentioned here are based on Engku Abdul Rahmans

(1988a,b) classication wherever possible. For timbers that have not been

classied by Engku Abdul Rahman, their strength grouping is based on

Burgess (1958).

** Malaysian Standard Code o Practice or Structural Use o Timber (MS

544:Part 2:2001).

16

(Engku Abdul Rahman,

1988a,b)

(MS 544:Part 2:2001)


17/19

17

Appendix 2: Strength Grouping o Timbers

* Commercially available

Source: Malaysian Standard Code o Practice or Structural Use o Timber (MS 544:Part 2:2001).

Appendix 3: Hazard Types and Required Treatment

HAZARD TYPE DRY SALT RETENTION REQUIRED

(kg/m3 (Ib/t3)

Mild Interior timber not used in contact with the ground 5.60 (0.35)

Moderate Exterior timber not used in contact with the ground 8.00 (0.50)

Severe Exterior timber used in contact with the ground 12.00 (0.75)

Very Severe Timber used in constant contact with resh water 16.00 (1.00)

Extremely Severe Timber used in marine environment 24.00 (1.50)

Requiring Treatment

SG2 SG3 SG4 SG5 SG6 SG7

DEDARU KELAT BERANGAN BABAI BAYUR ARA

KEMPAS* KEMBANG SEMANGKOK* DEDALI MALABERA DAMAR MINYAK BATAI

MERBATU* KULIM* DERUM BALEK ANGIN BOPENG DURIAN* GERONGGANG*

MERTAS PAUH KIJANG KAPUR* BINTANGOR* JELUTONG* LARAN

PENYAU KASAI* BRAZIL NUT JONGKONG PELAJAU

PERAH KERUNTUM DARK RED MERANTI KASAH PULAI*

PETALING MEMPENING GERUTU* LIGHT RED MERANTI* SESENDOK*

RANGGU MERANSI KEDONDONG* MACHANG* TERENTANG*

RU MERANTI BAKAU* KELEDANG* MEDANG*

SURIAN BATU MERAWAN* KERUING* MELANTAI*

TUALANG* MERPAUH* KETAPANG MERSAWA*

NYALIN KUNGKUR SENGKURAT

PERUPOK RUBBERWOOD* TERAP*

PUNAH* MELUNAK* YELLOW MERANTI*

RENGAS* MEMPISANG*

SIMPOH* MENGKULANG*

NYATOH*

PENARAHAN*PETAI

RAMIN*

SENGKUANG

SEPETIR*

TETEBU

WHITE MERANTI*

Naturally Durable

SG1 SG2 SG3 SG4 SG5

BALAU* BELIAN BEKAK* GIAM* TEMBUSU

BITIS MATA ULAT* DELEK MALABERA

CHENGAL* KEKATONG* KERANJI* MERBAU*PENAGA RESAK*


18/19

18

APPLICATION MAXIMUM M-C AT TIME MAXIMUM M-C AT

OF INSTALLATION FOR NON TIME OF INSTALLATION

AIR-CONDITIONED APPLICATIONS FOR AIR-CONDITIONED

APPLICATIONS (KILN-DRIED)

Structural Components

I. EXTERNAL-COLUMNS, BEAMS, BEARERS, STUDS, JOINTS, 30% (THICKNESS EXCEEDING 100MM) N.A

TIES & STRUT 25% (THICKNESS NOT EXCEEDING 100MM) N.A

ii. INTERNAL 19% 12%

Roofng

i. RAFTERS, TIES, STRUTS, PURLINS & BRACING 25% N.A.

ii. BATTENS 25% N.A.

Staircase

i. STRINGERS, TREADS, TRIMMER BEAMS & HANDRAILS 19% 12%

ii. BALUSTRADES 19% 12%

Flooring

i. FLOOR BOARDING & PARQUETRY 19% 12%

ii. SKIRTINGS 19% 12%

Walling

i. WALL, PARTITION, FRAMING 19% 12%

ii. EXTERNAL WALL BOARDING 19% N.A.

iii. INTERNAL WALL BOARDING, SLATES & SCREENS 19% 12%

iv. FACIA BOARDS 19% N.A.

Ceiling Frames

i. COVER BATTENS TO JOINTS OF CEILING SHEETS 25% N.A.

ii. CEILING STRIPS AND SOFFIT BATTENS 19% 12%

Door & Window Framesi. DOOR, WINDOW AND VENT FRAMES, INCLUDING THEIR 19% 12%

STOPS AND GROUNDS

ii. DOOR LEAVES, WINDOW AND VENT SASHES 19% 12%

Furniture

i. BUILT-IN FITTINGS AND FURNITURE GENERALLY 19% 12%

ii. WORKSHOP FURNITURE 19% 12%

iii. SCIENCE LABORATORY TOPS 19% 12%

Beading Fillets & Edgings generally 19% 12%

Appendix 4: Moisture Content (M-C) o Timber or Various Applications

(In Tropical Conditions)


19/19

19

Head Ofce

18th Floor, Menara PGRM

8, Jalan Pudu UluCheras, 56100 Kuala Lumpur

MALAYSIA

Tel: 603 92811999

Fax: 603 92828999

E-mail: [email protected]

London Ofce

24, Old Queen Street

London, SW1H9HP

UNITED KINGDOM

Tel: +44 207 2228188

Fax: +44 207 2228884E-mail: [email protected]

Shanghai Ofce

8C, Jinming Building

N0.8, South Zunyi Road

Changning District

200336, Shanghai

P.R. CHINA

Tel: +86 21 62197208

Fax: +86 21 62754060


Dubai Ofce

Suite 104, 1st Floor

Al Moosa Tower II

P.O. Box 62476, Dubai

UNITED ARAB EMIRATES

Tel: +971 4 3326998

Fax: +971 4 3326889


www.mtc.com.my

Step by Step Malay Timb

Documents