{"product_id":"treated-timber-joist-47-x-100mm-c24","title":"Treated Timber Joist 47 x 100mm C24","description":"\u003ch3\u003eTreated Timber Joist 47 x 100mm C24\u003c\/h3\u003e\n\nTreated Timber Joists are a robust and reliable choice for a wide range of construction and structural applications. Often referred to as softwood carcassing timber, these joists are C24 graded, meaning they meet strict structural standards for strength, stability, and performance in load-bearing projects.\n\nEach piece is pressure treated to protect against moisture, decay, and insect damage, making it suitable for above-ground use where there is an occasional risk of wetting. The timber is planed and regularised, giving it smooth surfaces, eased edges, and consistent dimensions for easy handling and a professional appearance.\n\nThese joists are also kiln dried to maintain a low and stable moisture content, which enhances their strength and prevents issues such as warping, twisting, or splitting over time. Available in 3.0m, 3.6m, 4.2m, 4.8m, and 6.0m lengths, they are ideal for roofing, flooring, wall framing, decking frameworks, and general carcassing.\n\nBacked by a 70% PEFC certification, this timber is responsibly sourced and environmentally conscious, ensuring a sustainable option without compromising on quality or durability.\n\n\u003ch3\u003eKey Specifications\u003c\/h3\u003e \u003cul\u003e \u003cli\u003e\n\u003cstrong\u003eSection Size:\u003c\/strong\u003e 47 x 100mm\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eFinished Size (Approx.):\u003c\/strong\u003e 45 x 95mm\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eLengths Available:\u003c\/strong\u003e 3.0m, 3.6m, 4.2m, 4.8m, 6.0m\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eGrade:\u003c\/strong\u003e C24 (Structural)\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eTreatment:\u003c\/strong\u003e Pressure Treated for protection and longevity\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eFinish:\u003c\/strong\u003e Planed and Regularised with Eased Edges\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eMoisture Content:\u003c\/strong\u003e Kiln Dried for improved stability\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eCertification:\u003c\/strong\u003e 70% PEFC Certified\u003c\/li\u003e \u003c\/ul\u003e \u003ch3\u003eFAQs\u003c\/h3\u003e \u003ch4\u003eWhat is C24 timber used for?\u003c\/h4\u003e C24 timber is a high-strength structural grade commonly used for flooring, roofing, decking, and wall framing. It provides excellent load-bearing performance with fewer knots and imperfections compared to lower-grade timber. \u003ch4\u003eCan treated C24 timber be used outdoors?\u003c\/h4\u003e Yes, C24 treated timber is suitable for outdoor use where it may occasionally get wet, such as in decking frameworks or pergolas. However, for ground contact or continuously wet environments, a higher treatment specification is recommended. \u003ch4\u003eWhy is kiln drying important for structural timber?\u003c\/h4\u003e Kiln drying reduces the timber’s moisture content, improving its strength, stability, and resistance to movement. This process also helps the preservative treatment penetrate more deeply, ensuring longer-lasting protection and durability.\u003cbr\u003e\u003cp\u003eCheck out our full range of \u003ca href=\"https:\/\/jjbuildingmaterials.co.uk\/collections\/timber\"\u003etimber\u003c\/a\u003e.\u003c\/p\u003e\u003cp\u003eBrowse more \u003ca href=\"https:\/\/jjbuildingmaterials.co.uk\/collections\/timber-lengths\"\u003etimber lengths\u003c\/a\u003e available online.\u003c\/p\u003e","brand":"JJ Building Materials","offers":[{"title":"3.0m","offer_id":51585205731670,"sku":"T00001138","price":6.84,"currency_code":"GBP","in_stock":true},{"title":"3.6m","offer_id":51585205764438,"sku":"T00001139","price":8.23,"currency_code":"GBP","in_stock":true},{"title":"4.2m","offer_id":51585205797206,"sku":"T00001140","price":9.61,"currency_code":"GBP","in_stock":true},{"title":"4.8m","offer_id":51585205829974,"sku":"T00001141","price":10.97,"currency_code":"GBP","in_stock":true},{"title":"6.0m","offer_id":51585205862742,"sku":"T00001143","price":21.87,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0905\/4509\/4998\/files\/treated-timber-joist-47-x-100mm-c24-7861726.jpg?v=1772656456","url":"https:\/\/jjbuildingmaterials.co.uk\/products\/treated-timber-joist-47-x-100mm-c24","provider":"JJ Building Materials","version":"1.0","type":"link"}