Kwila GL17S Laminated Beams 


Magna Merbau is a durable and economical option for applications where the beauty of the timber aesthetic is just as important as function. Not only is it strong, hard and straight it is naturally resistant to decay and termites as well as having a high fire rating. Magna’s glulam technology turns timber off-cuts into competitively priced high performance structural timber for both residential and commercial levels. With proven performance in the wider NZ market over many years you can be assured that these products are guaranteed to perform as designed.

Our Magna Merbau products are manufactured to Australian Standards under the quality assurance scheme operated by the Glue Laminated Timber Association of Australia. Glulam beams and handrails that are backed by a 15 year warranty*.


Magna Glulam is suitable for use in fully exposed weather conditions known as Service Class 3. This is because it is made from a naturally durable timber using Phenol-Resorcinol Formaldehyde (PRF)—a highly durable A bond adhesive. Merbau timber Magna Beams are also resistant to termite attack.

Sizes available:

Thickness Width
65 190, 240
80 190, 240, 290

Set lengths in these sizes are 4.8, 5.4, and 6.0m only

Timber Species: Merbau (also known as Kwila), Intsia bijuga
Origin: Indonesia
Moisture Level: Kiln dried to 12-16%
Standard: Manufactured to Australian Standard, AS/NZS 1328
Grade: A Grade appearance suitable for clear finishing
Durability: Natural durability class 1 above ground (40+ year life) as per AS 5604
Service Class: Suitable for class 3 (fully exposed situations) ***

*** GL13 and GL17 products are not considered suitable for extreme weather areas such as ski resorts or dry desert areas.

Engineer certified span tables are available below.

General: Very good working and finishing properties.
Sawing: Saws well but saw blades may ‘gum-up’ after prolonged sawing.
Planing: Excellent, some care required where grain irregularities occur.
Blunting: Moderate to severe
Boring: Additional power may be required, some burning may occur. Clean exit hole.
Turning: Denser material will not turn as well, and will tend to has a more fibrous finish.
Nailing: Pre-boring is recommended.
Gluing: Gluing can be difficult due to the natural oiliness of the timber.
Finishing: Excellent, will sand to a very fine finish and produce a high polish with golden lustre.

Note Merbau is prone to tannin bleed when in contact with water, we recommend it be kept dry at all times prior to coating with a good quality oil or paint, once coated any bleed will be greatly reduced.

Mechanical Properties
Strength: SD3.
Structural Grade: F27 (select grade).
Hardness (Janka): 8.6kN (seasoned), 7.6kN (unseasoned).
Max. Crushing Strength: 81MPa (seasoned), 55Mpa (unseasoned).
Modulus of Elasticity: 18GPa (seasoned), 14GPa (unseasoned).
Modulus of Rupture: 147MPa (seasoned), 103MPa (unseasoned).