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![C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 95 x 4800mm (4x2)]( "C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 95 x 4800mm (4x2)")
![C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 95 x 4800mm (4x2)]( "C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 95 x 4800mm (4x2)")
C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 95 x 4800mm (4x2)
£4.13 - £23.75 per piece (Ex VAT)£4.96 - £28.50 per piece (Inc VAT)Our planed & regularised treated sawn timber is perfect for structural timber carcassing as it comes in������C24 grade. This timber is ideal for a number of uses in the home and garden. The pressure treatment on this timber protects it against wood... -
![Rough Sawn Timber UC3u Treated Kiln Dried Regularised FSC 44 x 44mm]( "Rough Sawn Timber UC3u Treated Kiln Dried Regularised FSC 44 x 44mm")
![Rough Sawn Timber UC3u Treated Kiln Dried Regularised FSC 44 x 44mm]( "Rough Sawn Timber UC3u Treated Kiln Dried Regularised FSC 44 x 44mm")
Rough Sawn Timber UC3u Treated Kiln Dried Regularised FSC 44 x 44mm
£2.09 - £12.01 per piece (Ex VAT)£2.51 - £14.41 per piece (Inc VAT)Treated timber is suitable to be used externally and is suitable for wet areas or areas where the timber will be coming into contact with the ground. Examples of treated timber uses are outdoor decking, shed bases, posts, sleepers. Carcassing is a... -
![Timber Floor Joist UC3u Treated C16 FSC 44 x 145mm]( "Timber Floor Joist UC3u Treated C16 FSC 44 x 145mm")
![Timber Floor Joist UC3u Treated C16 FSC 44 x 145mm]( "Timber Floor Joist UC3u Treated C16 FSC 44 x 145mm")
Timber Floor Joist UC3u Treated C16 FSC 44 x 145mm
£6.20 - £35.63 per piece (Ex VAT)£7.44 - £42.76 per piece (Inc VAT)Our treated timber floor joists are designed for external use, making them ideal for wet areas or direct ground contact. Common applications include timber decking joists, shed bases, posts, and sleepers. Available in various timber joist dimensions,... -
![C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 47 x 75mm]( "C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 47 x 75mm")
![C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 47 x 75mm]( "C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 47 x 75mm")
C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 47 x 75mm
£3.13 - £18.01 per piece (Ex VAT)£3.76 - £21.61 per piece (Inc VAT)Treated timber is suitable to be used externally and is suitable for wet areas or areas where the timber will be coming into contact with the ground. Examples of treated timber uses are outdoor decking, shed bases, posts, sleepers. Regularised timber has... -
Special Offer
![C24 Timber Joists UC4 Treated Redwood 47 x 100 x 3600mm (4x2)]( "C24 Timber Joists UC4 Treated Redwood 47 x 100 x 3600mm (4x2)")
![C24 Timber Joists UC4 Treated Redwood 47 x 100 x 3600mm (4x2)]( "C24 Timber Joists UC4 Treated Redwood 47 x 100 x 3600mm (4x2)")
Special OfferC24 Timber Joists UC4 Treated Redwood 47 x 100 x 3600mm (4x2)
C24 deck joists are perfect for supporting your decked area. This timber is UC4 treated, meaning that not only is it ideal for outdoor use, but it is also suitable for direct contact with the ground. C24 graded timber is a premium loadbearing grade... -
Special Offer
![C24 Timber Joists UC4 Treated Redwood 47 x 100 x 4800mm (4x1)]( "C24 Timber Joists UC4 Treated Redwood 47 x 100 x 4800mm (4x1)")
![C24 Timber Joists UC4 Treated Redwood 47 x 100 x 4800mm (4x1)]( "C24 Timber Joists UC4 Treated Redwood 47 x 100 x 4800mm (4x1)")
Special OfferC24 Timber Joists UC4 Treated Redwood 47 x 100 x 4800mm (4x1)
C24 deck joists are perfect for supporting your decked area. This timber is UC4 treated, meaning that not only is it ideal for outdoor use, but it is also suitable for direct contact with the ground. C24 graded timber is a premium loadbearing grade... -
Special Offer
![C24 Timber Joists UC4 Treated Redwood 47 x 150 x 4800mm]( "C24 Timber Joists UC4 Treated Redwood 47 x 150 x 4800mm")
![C24 Timber Joists UC4 Treated Redwood 47 x 150 x 4800mm]( "C24 Timber Joists UC4 Treated Redwood 47 x 150 x 4800mm")
Special OfferC24 Timber Joists UC4 Treated Redwood 47 x 150 x 4800mm
C24 deck joists are perfect for supporting your decked area. This timber is UC4 treated, meaning that not only is it ideal for outdoor use, but it is also suitable for direct contact with the ground. C24 graded timber is a premium loadbearing grade... -
![C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 120mm]( "C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 120mm")
![C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 120mm]( "C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 120mm")
C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 120mm
£5.16 - £29.69 per piece (Ex VAT)£6.19 - £35.63 per piece (Inc VAT)Treated timber is suitable to be used externally and is suitable for wet areas or areas where the timber will be coming into contact with the ground. Examples of treated timber uses are outdoor decking, shed bases, posts, sleepers. Regularised timber has... -
![C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 220mm]( "C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 220mm")
![C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 220mm]( "C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 220mm")
C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 220mm
£9.29 - £53.44 per piece (Ex VAT)£11.15 - £64.13 per piece (Inc VAT)Treated timber is suitable to be used externally and is suitable for wet areas or areas where the timber will be coming into contact with the ground. Examples of treated timber uses are outdoor decking, shed bases, posts, sleepers. Regularised timber has... -
Special Offer
![ArborJoist Recycled Plastic Sub-Frame Decking Joists 3000 x 50 x 50mm]( "ArborJoist Recycled Plastic Sub-Frame Decking Joists 3000 x 50 x 50mm")
![ArborJoist Recycled Plastic Sub-Frame Decking Joists 3000 x 50 x 50mm]( "ArborJoist Recycled Plastic Sub-Frame Decking Joists 3000 x 50 x 50mm")
Special OfferArborJoist Recycled Plastic Sub-Frame Decking Joists 3000 x 50 x 50mm
The ArborJoist Recycled Plastic Sub-Frame system provides a high quality, high performance substructure, and a long-lasting and durable alternative to timber. As it is made from solid recycled plastic it means that is rot resistant and weather resistant,... -
![C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 170mm]( "C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 170mm")
![C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 170mm]( "C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 170mm")
C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 170mm
£7.23 - £41.57 per piece (Ex VAT)£8.68 - £49.88 per piece (Inc VAT)Treated timber is suitable to be used externally and is suitable for wet areas or areas where the timber will be coming into contact with the ground. Examples of treated timber uses are outdoor decking, shed bases, posts, sleepers. Regularised timber has... -
![C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 195mm]( "C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 195mm")
![C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 195mm]( "C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 195mm")
C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 195mm
£8.26 - £47.51 per piece (Ex VAT)£9.91 - £57.01 per piece (Inc VAT)Treated timber is suitable to be used externally and is suitable for wet areas or areas where the timber will be coming into contact with the ground. Examples of treated timber uses are outdoor decking, shed bases, posts, sleepers. Regularised timber has... -
![C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 97mm]( "C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 97mm")
![C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 97mm]( "C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 97mm")
C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 97mm
£6.59 - £37.90 per piece (Ex VAT)£7.91 - £45.48 per piece (Inc VAT)Treated timber is suitable to be used externally and is suitable for wet areas or areas where the timber will be coming into contact with the ground. Examples of treated timber uses are outdoor decking, shed bases, posts, sleepers. Regularised timber has... -
![C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 145mm]( "C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 145mm")
![C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 145mm]( "C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 145mm")
C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 145mm
£9.89 - £56.86 per piece (Ex VAT)£11.87 - £68.23 per piece (Inc VAT)Treated timber is suitable to be used externally and is suitable for wet areas or areas where the timber will be coming into contact with the ground. Examples of treated timber uses are outdoor decking, shed bases, posts, sleepers. Regularised timber has... -
Special Offer
![ArborJoist Recycled Plastic Sub-Frame Decking Joists 3000 x 125 x 50mm]( "ArborJoist Recycled Plastic Sub-Frame Decking Joists 3000 x 125 x 50mm")
![ArborJoist Recycled Plastic Sub-Frame Decking Joists 3000 x 125 x 50mm]( "ArborJoist Recycled Plastic Sub-Frame Decking Joists 3000 x 125 x 50mm")
Special OfferArborJoist Recycled Plastic Sub-Frame Decking Joists 3000 x 125 x 50mm
The ArborJoist Recycled Plastic Sub-Frame system provides a high quality, high performance substructure, and a long-lasting and durable alternative to timber. As it is made from solid recycled plastic it means that is rot resistant and weather resistant,... -
Special Offer
![C24 Timber Joists UC4 Treated Redwood 47 x 150 x 3600mm]( "C24 Timber Joists UC4 Treated Redwood 47 x 150 x 3600mm")
![C24 Timber Joists UC4 Treated Redwood 47 x 150 x 3600mm]( "C24 Timber Joists UC4 Treated Redwood 47 x 150 x 3600mm")
Special OfferC24 Timber Joists UC4 Treated Redwood 47 x 150 x 3600mm
C24 deck joists are perfect for supporting your decked area. This timber is UC4 treated, meaning that not only is it ideal for outdoor use, but it is also suitable for direct contact with the ground. C24 graded timber is a premium loadbearing grade... -
![C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 170mm]( "C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 170mm")
![C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 170mm]( "C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 170mm")
C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 170mm
£11.54 - £66.33 per piece (Ex VAT)£13.85 - £79.60 per piece (Inc VAT)Treated timber is suitable to be used externally and is suitable for wet areas or areas where the timber will be coming into contact with the ground. Examples of treated timber uses are outdoor decking, shed bases, posts, sleepers. Regularised timber has... -
![C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 245mm]( "C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 245mm")
![C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 245mm]( "C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 245mm")
C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 44 x 245mm
£8.46 - £53.25 per piece (Ex VAT)£10.15 - £63.90 per piece (Inc VAT)Treated timber is suitable to be used externally and is suitable for wet areas or areas where the timber will be coming into contact with the ground. Examples of treated timber uses are outdoor decking, shed bases, posts, sleepers. Regularised timber has... -
![C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 195mm]( "C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 195mm")
![C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 195mm]( "C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 195mm")
C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 195mm
£13.18 - £75.81 per piece (Ex VAT)£15.82 - £90.97 per piece (Inc VAT)Treated timber is suitable to be used externally and is suitable for wet areas or areas where the timber will be coming into contact with the ground. Examples of treated timber uses are outdoor decking, shed bases, posts, sleepers. Regularised timber has... -
![C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 220mm]( "C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 220mm")
![C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 220mm]( "C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 220mm")
C16 Timber Joists UC3u Treated Kiln Dried Regularised FSC 72 x 220mm
£14.83 - £85.28 per piece (Ex VAT)£17.80 - £102.34 per piece (Inc VAT)Treated timber is suitable to be used externally and is suitable for wet areas or areas where the timber will be coming into contact with the ground. Examples of treated timber uses are outdoor decking, shed bases, posts, sleepers. Regularised timber has... -
![C24 Timber Joists UC4 Treated Redwood 47 x 200 x 4800mm]( "C24 Timber Joists UC4 Treated Redwood 47 x 200 x 4800mm")
![C24 Timber Joists UC4 Treated Redwood 47 x 200 x 4800mm]( "C24 Timber Joists UC4 Treated Redwood 47 x 200 x 4800mm")
C24 Timber Joists UC4 Treated Redwood 47 x 200 x 4800mm
£42.11 - £242.12 each (Ex VAT)£50.53 - £290.54 each (Inc VAT)C24 deck joists are perfect for supporting your decked area. This timber is UC4 treated, meaning that not only is it ideal for outdoor use, but it is also suitable for direct contact with the ground. C24 graded timber is a premium loadbearing grade...
Decking Joists
When choosing the right decking joists for your project, the size you need will depend on the overall dimensions of your deck. We offer a variety of decking and joists in different lengths, all available for delivery from any of our branches. For timber decking, a good rule of thumb for decking joist spacing is 450mm centres (or 400mm if using a chevron pattern). For composite decking joists, spacing should be 400mm centres, or 300mm when opting for a chevron pattern.
Additionally, consider using deck joist tape to protect the joists from moisture, and joist hangers for decking to ensure a secure and durable installation.
Frequently Asked Questions
What size deck joists?
The deck joist size required depends on your project design. Our most popular sizes are 47x100mm, 47x125mm, and 47x150mm. These are available from every Howarth branch in lengths of 3m, 3.6m, 4.2m, and 4.78m. We also have availability of 5.4m and 6m at select branches
What size screws for decking joists?
Camo deck screws are perfect for fastening deck boards to joists. For the framing, structural wood screws will do a great job.
How far apart should deck joists be?
When designing how far apart your deck joists should be, a good timber decking spacing is 450mm centres (or 400mm centres is using a chevron pattern), and 400mm centres for composite decking (or 300mm centres if using a chevron pattern).
How many decking joists do I need?
The number of decking joists needed is dependant upon the size of the decking project. It can be calculated based on spacing of 450mm centres for timber decking (400mm centres for chevron pattern) and 400mm centres for composite decking (300mm centres for chevron pattern).
What wood to use for deck joists?
C16 or C24 timber is ideal for decking joists. It is structural graded and when well put together will keep the decking strong and stable.
How thick should decking joists be?
Decking joists are most commonly 47mm in size.
Should I stain deck joists?
We always recommend treating timber and maintaining it over time, this includes decking joists. This will increase the longevity of the decking structure. Don’t forget to protect the ends!
How to guides
How to build a deck
How to build a decking using our timber products.
How to build a raised deck
A step by step guide on how to build your own raised decking area.