{"product_id":"treated-timber-joist-47-x-175mm-c24","title":"Treated Timber Joist 47 x 175mm C24","description":"\u003ch3\u003eTreated Timber Joist 47 x 175mm C24\u003c\/h3\u003e\n\nTreated Timber Joists are a high-performance, reliable choice for structural construction work, offering strength, stability, and versatility. Commonly referred to as softwood carcassing timber, these joists are graded to C24, meaning they meet the highest structural standards and are suitable for load-bearing applications in both domestic and commercial builds.\n\nEach joist is pressure treated to enhance its resistance against moisture, fungal decay, and insect attack — making it suitable for above-ground use where occasional wetting may occur. The timber is also planed and regularised, providing smooth, consistent section sizes with eased edges for easy handling and a professional finish.\n\nThese joists are kiln-dried to reduce moisture content and prevent warping or twisting, ensuring long-term stability and strength. Available in lengths ranging from 3.0m to 6.0m, they’re ideal for floors, walls, roofs, and general carcassing applications. With a PEFC 70% certification, this timber is responsibly sourced, ensuring sustainable forest management while maintaining exceptional quality.\n\n\u003ch3\u003eKey Specifications\u003c\/h3\u003e \u003cul\u003e \u003cli\u003e\n\u003cstrong\u003eSection Size:\u003c\/strong\u003e 47 x 175mm\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eFinished Size (Approx.):\u003c\/strong\u003e 45 x 170mm\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 durability\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 does the C24 grade mean for timber joists?\u003c\/h4\u003e C24 is a high structural grade that signifies superior strength and quality. It’s ideal for load-bearing applications such as floors, roofs, and walls, offering better stability and fewer natural defects than lower grades like C16. \u003ch4\u003eCan treated timber joists be used outdoors?\u003c\/h4\u003e Yes, C24 treated timber is suitable for external use where there’s an occasional risk of wetting. However, for timber in direct ground contact or constantly wet environments, a higher treatment specification is recommended. \u003ch4\u003eWhy is kiln drying important for structural timber?\u003c\/h4\u003e Kiln drying lowers the timber’s moisture content, making it more stable and less prone to warping, cracking, or twisting. It also ensures the preservative treatment penetrates more effectively, extending the timber’s lifespan and reliability.\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":51585205272918,"sku":"T00001164","price":12.02,"currency_code":"GBP","in_stock":true},{"title":"3.6m","offer_id":51585205305686,"sku":"T00001165","price":14.41,"currency_code":"GBP","in_stock":true},{"title":"4.2m","offer_id":51585205338454,"sku":"T00001166","price":16.82,"currency_code":"GBP","in_stock":true},{"title":"4.8m","offer_id":51585205371222,"sku":"T00001167","price":28.88,"currency_code":"GBP","in_stock":true},{"title":"6.0m","offer_id":51585205403990,"sku":"T00001169","price":37.17,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0905\/4509\/4998\/files\/treated-timber-joist-47-x-175mm-c24-3654400.jpg?v=1772656456","url":"https:\/\/jjbuildingmaterials.co.uk\/products\/treated-timber-joist-47-x-175mm-c24","provider":"JJ Building Materials","version":"1.0","type":"link"}