
C24 Sawn Green Treated Timber Support 47mm x 150mm
Cladco’s 47mm × 150mm C24 sawn green treated timber supports offer excellent strength for structural use. FSC®-certified and pressure-treated with Tanalith ‘E’, these long-lasting joists are ideal for roofing or decking subframes. Available in 4.2m and 4.8m lengths, kiln-dried to help reduce splitting and twisting.
A High-Strength Timber Solution — Built for Roofing Loads and Decking Frameworks
Our 47mm × 150mm C24 sawn green treated timber support is a high-performance structural timber, ideal for forming durable subframes beneath roofing systems and decking installations. Carefully kiln-dried to minimise twisting or splitting, this robust timber is graded to C24 standards for maximum load-bearing performance across residential and commercial projects.
Compared to C16 timber, C24 offers approximately 50% greater strength, featuring fewer knots and a denser grain structure. Its slower natural growth results in more durable fibre composition, allowing for longer unsupported spans and increased weight capacity, making it an ideal choice for demanding builds requiring long-term reliability.
Each timber joist is FSC®-certified, ensuring it’s responsibly sourced, and is treated with high-pressure Tanalith ‘E’ preservative for resistance to rot, decay, and insect attack. The green treatment provides long-lasting protection from the elements, making it suitable for year-round outdoor use in exposed environments.
Timber specifications
- Lengths: 4.2m and 4.8m
- Width: 150mm
- Depth: 47mm
- Weight (Approx.): 14.94kg (4.2m)
- Weight (Approx.): 17.07kg (4.8m)
Adaptable and easy to work with, this timber can be sawn, planed, or drilled to suit your construction needs. For decking, the joist provides a strong and stable base beneath your boards and performs best when installed on a solid concrete decking block. When used in roofing frameworks, such as for rafters or purlin supports, the timber delivers the strength required for more demanding structural setups.
Cladco recommends using these joists in combination with our timber posts and fixings for a complete structural solution. Be sure to consult our online installation guides for expert tips and best practices during fitting.
Whether you're building a garden deck or forming part of a structural roofing system, this high-grade timber joist delivers long-lasting performance with excellent strength and stability.
Looking for an alternative timber joist?
See our C24 sawn green treated timber joist 47mm × 100mm
Or browse our framework department for roofing framework, decking support and more…
Please note images may vary from the actual item supplied due to lighting variations and camera angles.
Order A Sample Pack!

Click Here to view our installation guide.
Download the datasheet for C24 Sawn Green Treated Timber Support 47mm x 150mm
Type | When? | Cost? | ||
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National Delivery | Orders under £1,000 | Est. 5 working days* Roofing items 7-10 working days* |
£192.00 |
Orders over £1,000 | Est. 5 working days* Roofing items 7-10 working days* |
£96.00 | ||
Orders over £1,500 | Est. 5 working days* Roofing items 7-10 working days* |
FREE | ||
Scotland Delivery | Est. 15 working days* Roofing items 7-10 working days* |
£360.00 | ||
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Millboard Delivery | Orders under £2,000 | Est. 5 working days* | £192.00 |
Orders over £2,000 | Est. 5 working days* | FREE | ||
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Parcelforce Standard | (Small Parcels) | 3-5 working days* | £8.50 |
Parcelforce Standard | (Large Parcels) | 3-5 working days* | £30.00 | |
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Sample Packs via Courier | 5 working days* | FREE |
*Please allow for public holidays and weekends (non-delivery days)
Some of our products are available for collection from our warehouses in Okehampton (Devon) and Andover (Hampshire) - This option will show at checkout, when available.
Standard collection lead time is 3-5 working days, this may vary depending on the product. If you would like to collect your order after 2 hours, please choose this option at checkout.
Please note that collections are only available from Monday-Friday, 08:00 - 17:00 & Saturday, 08:00 - 12:30 (Note: this IS the cut off time for collections, despite our closing time of 13:00)
Please Note The Following Prior To Collection:
Vehicles we can and cannot load
Cladco Profiles will only load flatbed lorries and flatbed trailers for insurance purposes. If the appropriate vehicle is not available, two people would be required for a collection.
Cladco Profiles will NOT load any vehicles with roof racks, horse boxes, cattle lorries or fixed-sided trailers. Cladco Profiles has the right to refuse loading a vehicle for any reason.
Before arranging a collection, please read our Customer Collection Notice below.

Our Okehampton HQ and Warehouses (Devon)

Our Andover Warehouses (Hampshire)








Customer Collection Notice
For those customers wishing to collect materials, we ask you report to the office first in order to be seen by a member of the sales team. Your goods will then be picked and brought to your vehicle.
Please note that during busy periods you may experience a wait while our yard staff serve other customers or are loading/unloading other vehicles.
We respectfully draw your attention to the following points:
- It is the ultimately the responsibility of the customer to load his/her vehicle and to ensure the goods are safely/ securely strapped down.
- Our staff will be happy to assist you load your goods onto appropriate vehicles by way of fork lift trucks. Our staff will not handball any goods into enclose vehicles. The loading of the vehicle is carried out entirely at the customers own risk. We will not be held liable for any damage that may occur to your vehicle or goods collected from our premises during the transport of said goods.
- It is the responsibility of the customer to ensure both their vehicle and the goods are safe when they leave our premises.
- We can advise the approximate weight of materials prior to you arriving so that you can be sure your vehicle is capable of carrying the intended load. Please ensure that you bring appropriate ropes, straps or other securing materials as we are unable to provide you with any upon arrival.
- We strongly recommend you bring suitable protection materials to prevent your ropes/straps etc. be damaged by these edges. We recommend that you use good quality protective gloves when handling materials.