{"product_id":"spotted-gum-timber-decking","title":"Spotted Gum Timber Decking","description":"\u003cp\u003eSpotted Gum decking in 86 × 19 mm and 135 × 19 mm: a dense Australian hardwood with Class 1 durability above ground, Janka hardness 10.1 kN and a place on the AS 3959 bushfire-resisting timber list, so it can be used for decking up to BAL-29.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSizes and lengths:\u003c\/strong\u003e 86 × 19 mm and 135 × 19 mm in random lengths, plus 135 × 19 mm long lengths of 5.7–6.0 m for fewer joins\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTimber:\u003c\/strong\u003e Spotted Gum (\u003cem\u003eCorymbia maculata\u003c\/em\u003e, \u003cem\u003eC. citriodora\u003c\/em\u003e and \u003cem\u003eC. henrii\u003c\/em\u003e), grown from north-east Victoria to Queensland; light brown to dark red-brown; about 990–1010 kg\/m³\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDurability:\u003c\/strong\u003e Class 1 above ground, which the Queensland Government rates at more than 40 years’ expected life; Class 2 in-ground; the heartwood is termite resistant\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTannin:\u003c\/strong\u003e WoodSolutions says Spotted Gum is less prone to tannin bleed than other species\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBushfire:\u003c\/strong\u003e on the AS 3959 list of bushfire-resisting timbers, so it can be used for decking up to BAL-29 (BAL-40 and Flame Zone need tested systems)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eJoist spacing:\u003c\/strong\u003e 450 mm centres, as WoodSolutions recommends for decking; its deck design guide allows up to 500 mm for 19 mm hardwood, or 350 mm if the boards run at 45°\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGaps:\u003c\/strong\u003e 3–4 mm between 86 mm boards and 4–5 mm between 135 mm boards at installation (WoodSolutions deck design guide)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHow much for a deck:\u003c\/strong\u003e a 20 m² deck needs about 140 lineal metres of 135 mm board or about 225 lineal metres of 86 mm, plus about 10% for offcuts\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLow decks:\u003c\/strong\u003e under 400 mm off the ground, WoodSolutions suggests 5–6 mm gaps and at least 40 mm between the deck and the house, for airflow\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFixing:\u003c\/strong\u003e two fixings per board at every joist, at least 12 mm from edges and ends. Pre-drill this dense hardwood. Use stainless steel within 1 km of the coast or 1 m of a pool. See our \u003ca href=\"\/collections\/decking-accessories\"\u003edecking screws\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFinishing:\u003c\/strong\u003e coat every face and cut end, ideally before fixing, then recoat at least once a year or as the oil maker directs (WoodSolutions); left bare, it weathers to silver-grey. Oils we stock: \u003ca href=\"\/products\/cutek-oil-extreme-cd50\"\u003eCUTEK CD50\u003c\/a\u003e, \u003ca href=\"\/products\/intergrain-universal-timber-oil\"\u003eIntergrain Universal Timber Oil\u003c\/a\u003e or \u003ca href=\"\/products\/sceneys-timber-decking-oil\"\u003eSceney’s Timber Decking Oil\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAt Greenhill:\u003c\/strong\u003e stocked at 170 Settlement Road, Thomastown, with pickup or delivery across Melbourne and regional Victoria. Compare species on our \u003ca href=\"\/collections\/timber-decking\"\u003ehardwood decking\u003c\/a\u003e page.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eUsing Spotted Gum inside as well? See \u003ca href=\"\/collections\/spotted-gum-flooring\"\u003eSpotted Gum flooring\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2\u003eSpotted Gum decking: sizes, lengths and prices\u003c\/h2\u003e\n\u003ctable class=\"ght-sizes\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eSize\u003c\/th\u003e\n\u003cth\u003eLengths\u003c\/th\u003e\n\u003cth\u003ePrice\u003c\/th\u003e\n\u003cth\u003eAvailability\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e135 × 19 mm\u003c\/td\u003e\n\u003ctd\u003eLong Lengths (5.7-6.0m)\u003c\/td\u003e\n\u003ctd\u003e$140.36 per board\u003c\/td\u003e\n\u003ctd\u003ein stock\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e135 × 19 mm\u003c\/td\u003e\n\u003ctd\u003eRandom Length\u003c\/td\u003e\n\u003ctd\u003e$16.50 per lineal metre\u003c\/td\u003e\n\u003ctd\u003ein stock\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e86 × 19 mm\u003c\/td\u003e\n\u003ctd\u003eRandom Length\u003c\/td\u003e\n\u003ctd\u003e$9.60 per lineal metre\u003c\/td\u003e\n\u003ctd\u003ein stock\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003eRandom lengths are the usual way to buy it and the cheapest per metre: packs run from about 1.8 m up to 5.4 m and you cut to suit. The 135 × 19 mm long-length boards are 5.7–6.0 m pieces for decks where you want a run with no joins. Prices are our website prices on 14 October 2026 and are per lineal metre unless marked per board; a 20 m² deck needs about 140 lineal metres of 135 mm board or 225 of 86 mm, plus 10% for cuts.\u003c\/p\u003e\n\u003ch2\u003eWhat Spotted Gum decking is like\u003c\/h2\u003e\n\u003cp\u003eSpotted Gum is the hardwood most Melbourne builders reach for when a customer wants an Australian species rather than Merbau. It is a group of three closely related trees, \u003cem\u003eCorymbia maculata\u003c\/em\u003e, \u003cem\u003eC. citriodora\u003c\/em\u003e and \u003cem\u003eC. henryi\u003c\/em\u003e, cut from Queensland down to the NSW south coast. The boards run from pale brown to a dark red-brown, often in the same pack, with a wavy grain that shows the figure once it is oiled. At about 990 kg\/m³ seasoned it is heavy; a 5.4 m length of 135 × 19 weighs around 14 kg.\u003c\/p\u003e\n\u003cp\u003eWoodSolutions puts its seasoned hardness at 10.1 kN, above Blackbutt (8.9) and Merbau (8.5), and rates the heartwood durability Class 1 above ground and Class 2 in the ground, with natural termite resistance. It is also the lowest-bleed hardwood we sell: WoodSolutions describes it as less prone to tannin bleed than other species, so it is the safer pick next to pale paving or render. The sapwood can be attacked by lyctid borer, which is why decking is cut from heartwood.\u003c\/p\u003e\n\u003ch2\u003eWhere it suits\u003c\/h2\u003e\n\u003cp\u003eSpotted Gum is on the AS 3959 list of bushfire-resisting timbers, so at 19 mm it can be used for decking up to BAL-29 without any treatment; BAL-40 and Flame Zone need a tested system. That, the hardness and the low bleed make it the all-round choice: house decks, pool surrounds, steps and commercial outdoor areas. The one place we would steer you elsewhere is a deck that stays wet and shaded most of the year, where grey ironbark or Grey Box, both Class 1 in the ground as well, give more margin.\u003c\/p\u003e\n\u003ch2\u003eFixing and finishing\u003c\/h2\u003e\n\u003cp\u003ePre-drill every fixing: at this density screws will snap or split the board end otherwise. Use two stainless or Class 3 galvanised screws per board at each joist, 450 mm joist centres, and a 4–5 mm gap on the 135 mm board (3–4 mm on 86 mm). Coat all faces and cut ends before laying, then once or twice a year. The \u003ca href=\"\/products\/cutek-oil-extreme-cd50\"\u003eCUTEK Extreme CD50\u003c\/a\u003e and \u003ca href=\"\/products\/intergrain-universal-timber-oil\"\u003eIntergrain Universal Timber Oil\u003c\/a\u003e on our shelves both suit it; left bare it silvers within a year. Screws, joist tape and stirrups are in \u003ca href=\"\/collections\/decking-accessories\"\u003edecking accessories\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch2\u003eThe same timber for other jobs\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003ca href=\"\/collections\/spotted-gum-flooring\"\u003eSpotted Gum flooring\u003c\/a\u003e – solid, engineered, hybrid and laminate floors in the same timber\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/spotted-gum-timber-flooring\"\u003eNSW Spotted Gum solid floorboards\u003c\/a\u003e – 83 × 14, 130 × 14 and 130 × 19 mm\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/qld-spotted-gum-timber-flooring\"\u003eQLD Spotted Gum solid floorboards\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/collections\/timber-decking\"\u003eHardwood decking\u003c\/a\u003e – all six species side by side\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eCompare the species\u003c\/h2\u003e\n\u003cp\u003eOur \u003ca href=\"\/blogs\/guides\/decking-timber-comparison-melbourne\"\u003edecking timber comparison\u003c\/a\u003e puts hardness, durability, bushfire rating and price per metre for all six hardwoods on one page; \u003ca href=\"\/collections\/merbau\"\u003eMerbau decking\u003c\/a\u003e is the budget alternative.\u003c\/p\u003e\n\u003ch2\u003eQuestions we get asked\u003c\/h2\u003e\n\u003ch3\u003eHow much does Spotted Gum decking cost?\u003c\/h3\u003e\n\u003cp\u003eOn our website on 14 October 2026, 86 × 19 mm random lengths are $9.60 per lineal metre and 135 × 19 mm $16.50 per lineal metre, so a 20 m² deck is roughly $2,400–$2,550 in boards including 10% for cuts, before fixings and oil.\u003c\/p\u003e\n\u003ch3\u003eIs Spotted Gum better than Merbau for decking?\u003c\/h3\u003e\n\u003cp\u003eIt is harder (10.1 kN against 8.5), bleeds far less tannin, and is Australian-grown; Merbau is cheaper per metre and comes in more widths. Both are Class 1 above ground and both are BAL-29 timbers.\u003c\/p\u003e\n\u003ch3\u003eCan I use Spotted Gum decking in a BAL-29 area?\u003c\/h3\u003e\n\u003cp\u003eYes. It is on the bushfire-resisting timber list in AS 3959, so 19 mm boards can be used for decking up to BAL-29. BAL-40 and Flame Zone need a tested deck system.\u003c\/p\u003e\n\u003ch3\u003eWhat colour does it go?\u003c\/h3\u003e\n\u003cp\u003eOiled, the boards keep their light-brown to red-brown range and the grain shows. Left uncoated it weathers to silver-grey in about a year and can be brought back with a deck cleaner and oil.\u003c\/p\u003e\n\u003ch3\u003eDoes it need pre-drilling?\u003c\/h3\u003e\n\u003cp\u003eYes, every screw. It is dense enough to shear screws and split board ends if you drive straight in.\u003c\/p\u003e\n\u003ch2\u003ePickup and delivery\u003c\/h2\u003e\n\u003cp\u003eStocked at 170 Settlement Road, Thomastown, Mon–Fri 7 am–4:30 pm and Sat 9 am–1 pm. We pack and load it for you, or deliver across Melbourne and regional Victoria; delivery is quoted with the order. Call (03) 9465 9875 with your sizes and we will work out the lineal metres and the price.\u003c\/p\u003e\n","brand":"Greenhill Timbers","offers":[{"title":"Random Length \/ 135 x 19mm","offer_id":68913643257890,"sku":"GHT-9972","price":16.5,"currency_code":"AUD","in_stock":true},{"title":"Random Length \/ 86 x 19mm","offer_id":68913643290658,"sku":"GHT-9971","price":9.6,"currency_code":"AUD","in_stock":true},{"title":"Long Lengths (5.7-6.0m) \/ 135 x 19mm","offer_id":68913643323426,"sku":"GHT-9970","price":140.36,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0917\/3981\/5970\/files\/spotted-gum-135-19-img.jpg?v=1792367796","url":"https:\/\/greenhilltimbers.com.au\/products\/spotted-gum-timber-decking","provider":"Greenhill Timbers","version":"1.0","type":"link"}