Timber Guide – Understanding Timber Types, Grades, Finishes
1. Timber Species
| Species | Description |
|---|---|
| Spotted Gum | Premium Australian hardwood known for strength, durability, and modern appearance. Ideal for decking, screening, and structural use. |
| Merbau | Highly durable hardwood commonly used for decking and outdoor projects. Naturally resistant to weather and termites. |
| Treated Pine | Cost-effective softwood treated for outdoor use. Available in different treatment levels depending on exposure. |
| Radiata Pine | Versatile softwood used for structural and non-structural applications. Often treated for external use. |
| Pine | General-purpose softwood used in framing, mouldings, and interior applications. |
| Rubberwood | Sustainable hardwood alternative used mainly for indoor applications such as joinery and furniture. |
| Plywood / Ply | Engineered sheet material made from timber veneers. Used for flooring, bracing, and general construction. |
| Radiata Plywood | Lightweight plywood option commonly used for non-structural applications. |
| Marine Plywood | High-grade plywood designed for wet environments with strong water resistance. |
2. Timber Treatments
| Treatment | Description |
|---|---|
| H2 | Internal use with termite protection. |
| H3 | Outdoor above-ground use (decks, pergolas, cladding). |
| H4 | Suitable for in-ground contact (posts, sleepers). |
| H5 | Heavy-duty in-ground use with high moisture exposure. |
| LOSP | Light Organic Solvent Preservative — protects timber while maintaining a clean finish. |
| LOSP H3 | Above-ground protection with smoother finish than traditional treated timber. |
| Treated (T2) | Termite-treated timber for internal structural applications. |
| Untreated (UT) | No treatment — suitable for dry indoor environments only. |
| Kiln Dried (KD) | Timber dried to reduce moisture, improving stability and reducing movement. |
3. Structural Timber Grades
| Grade | Description |
|---|---|
| MGP10 / MGP12 / MGP15 | Machine graded pine used for structural framing. Higher number = higher strength. |
| F7 – F27 | Hardwood structural grades. Higher number indicates greater load-bearing capacity. |
| GL8 – GL20 | Glulam engineered beams used for structural applications. |
| LVL10 / LVL14 / LVL18 | Engineered timber beams for long spans and structural strength. |
4. Appearance & General Timber Grades
| Grade | Description |
|---|---|
| Clear | Premium timber with minimal knots and clean appearance. |
| Select | High-quality timber with minimal natural features. |
| Select Tight Knots | Clean timber with small, tight knots. |
| Feature Grade | Natural timber look with visible knots and variation. |
| Standard / Standard & Better | General-purpose timber with mixed appearance quality. |
| Merchant Grade | Cost-effective timber with more visible imperfections. |
| Commercial Grade | Lower appearance grade suitable for non-visible use. |
| Tight Knot | Structural timber with small, tight knots. |
| Mech | Machine graded timber classification. |
| FJ (Finger Jointed) | Engineered timber joined for stability and length consistency. |
5. Plywood Grades
| Grade | Description |
|---|---|
| CD | One rough face (D) and one better face (C). Structural use where appearance is not critical. |
| BC | Higher quality face (B) with a secondary face (C). Suitable for visible applications. |
6. Planing (Surface Finish)
| Type | Description |
|---|---|
| DAR (Dressed All Round) | Smooth finish on all sides, ready to use or paint. |
| S4S (Surfaced Four Sides) | Smooth and uniform on all faces. |
| RS (Rough Sawn) | Raw timber finish with a natural textured surface. |
7. Finishes
| Finish | Description |
|---|---|
| Raw / Natural | Unfinished timber ready for treatment or coating. |
| Primed | Pre-coated and ready for painting. |
| Oiled / Pre-oiled | Treated with oil to enhance durability and natural appearance. |
| Stained | Coloured finish while retaining timber grain. |
| Varnished | Protective coating with a polished finish. |
| Clear Lacquer | Transparent coating for protection while showing natural timber. |
8. Timber Profiles
Structural & Outdoor Profiles
| Profile | Description |
|---|---|
| Decking | Boards designed for outdoor flooring. |
| Screening | Used for privacy screens and feature panels. |
| Posts | Vertical structural supports. |
| Sleeper | Used for retaining walls and landscaping. |
Board & Sheet Profiles
| Profile | Description |
|---|---|
| T&G (Tongue & Groove) | Interlocking boards for flooring and wall applications. |
| Square Edge | Clean, straight edges for a modern look. |
| Bevel Edge | Angled edges used in cladding and decking. |
Mouldings & Finishing Profiles
| Profile | Description |
|---|---|
| Bullnose | Rounded edge finish. |
| QUAD / TRI Quad | Internal trim used for finishing joins. |
| 321 Lining | Wall and ceiling lining profile. |
| 302 Lining | Decorative lining profile. |
| W/B Stop | Window and door finishing trim. |
| Bottom Rail | Structural support in fencing or balustrades. |
| Hand Rail | Used for stairs and balustrades. |
| Bevel | Decorative angled profile. |
| Half Splay (33mm) | Feature moulding with angled face. |
| Colonial | Traditional decorative timber profile. |
Quick Reference Guide
| If You Need… | Choose… |
|---|---|
| Structural strength | MGP, F-grade, LVL |
| Outdoor timber | H3 treated or hardwood |
| In-ground timber | H4 or H5 treated |
| Premium appearance | Clear, Select, Hardwood |
| Budget option | Treated Pine |
Need Help Choosing?
Still unsure? Contact Timber M8 and tell us:
- what you’re building
- where it will be used
- whether it touches the ground
- your budget
We’ll help you choose the right timber for your project.
