The Story
Treated sawn timber 50mm x 100mm (4x2) is a general-purpose rough sawn section pressure treated to resist rot and insect attack. Ideal for outdoor above-ground construction, this 4.8 metre length suits fencing frameworks, decking subframes, and garden structures where appearance is secondary to function.
Specifications
| Property | Detail |
|---|---|
| Material | Softwood timber |
| Treatment | Pressure treated preservative |
| Finish | Rough sawn |
| Nominal Size | 50mm x 100mm (4x2) |
| Length | 4.8m (4800mm / 16ft) |
| Use Class | Above ground (not suitable for direct ground contact) |
What it's used for
- Decking subframes and joist structures where the timber will sit above ground level
- Fence rails and framing for close-board, hit-and-miss, and panel fence systems
- Pergola and garden structure framing, including planter boxes and raised bed surrounds
- General outdoor carpentry where the timber will be clad, concealed, or further finished
Fitting and handling
Store the timber flat and off the ground in a well-ventilated area before use, allowing it to acclimatise to site conditions for at least 48 hours where possible. Fix using galvanised or stainless steel fasteners to avoid corrosion staining, particularly in exposed outdoor applications. Seal all cut ends promptly with a compatible end-grain preservative to maintain the full protection of the treatment and extend the service life of the timber.
FAQ
Is 50mm x 100mm treated sawn timber suitable for decking joists?
Yes, 50x100mm treated sawn timber is widely used as a decking joist or bearer where the section sits above ground level. It is not rated for direct ground contact, so always keep it clear of soil and standing water, or use a dedicated ground-contact rated section for any posts or bearers that meet the ground.
What is the difference between nominal size and finished size for 4x2 sawn timber?
The nominal size of 50mm x 100mm refers to the target sawn dimensions. Because the timber is rough sawn rather than planed, the actual finished size is typically close to nominal but may vary slightly due to the sawing process. If you need precise dimensions, consider a planed or PSE section instead.
Do I need to treat cut ends of pressure treated timber?
Yes. Cutting through pressure treated timber exposes untreated wood fibre at the cut face. Always apply a compatible end-grain preservative or cut-end treatment to any sawn surfaces before fixing in place. This is particularly important for outdoor applications where the timber is exposed to rain or moisture.
For related outdoor timber products, browse the fence rails collection at Nottage Timber Merchants. We supply trade and retail customers across Bridgend and South Wales, with next-day delivery available to many local postcodes. Visit us in store or order online for straightforward advice and honest pricing.
Description
Treated sawn timber 50mm x 100mm (4x2) is a general-purpose rough sawn section pressure treated to resist rot and insect attack. Ideal for outdoor above-ground construction, this 4.8 metre length suits fencing frameworks, decking subframes, and garden structures where appearance is secondary to function.
Specifications
| Property | Detail |
|---|---|
| Material | Softwood timber |
| Treatment | Pressure treated preservative |
| Finish | Rough sawn |
| Nominal Size | 50mm x 100mm (4x2) |
| Length | 4.8m (4800mm / 16ft) |
| Use Class | Above ground (not suitable for direct ground contact) |
What it's used for
- Decking subframes and joist structures where the timber will sit above ground level
- Fence rails and framing for close-board, hit-and-miss, and panel fence systems
- Pergola and garden structure framing, including planter boxes and raised bed surrounds
- General outdoor carpentry where the timber will be clad, concealed, or further finished
Fitting and handling
Store the timber flat and off the ground in a well-ventilated area before use, allowing it to acclimatise to site conditions for at least 48 hours where possible. Fix using galvanised or stainless steel fasteners to avoid corrosion staining, particularly in exposed outdoor applications. Seal all cut ends promptly with a compatible end-grain preservative to maintain the full protection of the treatment and extend the service life of the timber.
FAQ
Is 50mm x 100mm treated sawn timber suitable for decking joists?
Yes, 50x100mm treated sawn timber is widely used as a decking joist or bearer where the section sits above ground level. It is not rated for direct ground contact, so always keep it clear of soil and standing water, or use a dedicated ground-contact rated section for any posts or bearers that meet the ground.
What is the difference between nominal size and finished size for 4x2 sawn timber?
The nominal size of 50mm x 100mm refers to the target sawn dimensions. Because the timber is rough sawn rather than planed, the actual finished size is typically close to nominal but may vary slightly due to the sawing process. If you need precise dimensions, consider a planed or PSE section instead.
Do I need to treat cut ends of pressure treated timber?
Yes. Cutting through pressure treated timber exposes untreated wood fibre at the cut face. Always apply a compatible end-grain preservative or cut-end treatment to any sawn surfaces before fixing in place. This is particularly important for outdoor applications where the timber is exposed to rain or moisture.
For related outdoor timber products, browse the fence rails collection at Nottage Timber Merchants. We supply trade and retail customers across Bridgend and South Wales, with next-day delivery available to many local postcodes. Visit us in store or order online for straightforward advice and honest pricing.
