{"id":3060,"date":"2005-01-05T12:00:10","date_gmt":"2005-01-05T10:00:10","guid":{"rendered":"https:\/\/woodenhottubsale.co.uk\/product\/fiberglass-inner-frame\/"},"modified":"2026-08-08T08:34:17","modified_gmt":"2026-08-08T06:34:17","slug":"sunken-in-ground-hot-tub","status":"publish","type":"product","link":"https:\/\/www.woodenhottubsale.co.uk\/ie\/product\/sunken-in-ground-hot-tub\/","title":{"rendered":"TimberIN Nordic\u2122 InGround Comfort \u2013 Sunken & In-Ground Hot Tub System"},"content":{"rendered":"
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Purpose-built shells for terraces and recessed installations \u00b7 Made-to-order outdoor hot tub<\/p>\n

TimberIN Nordic\u2122 InGround Comfort \u2013 Sunken & In-Ground Hot Tub System: an in-ground model family that starts with the construction drawing<\/h2>\n

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The visible rim is only a small part of the installation<\/h2>\n

A recessed hot tub can create a calm, integrated terrace, but the finished appearance depends on substantial work below and around the shell. Round models give a communal seating arrangement, the Ofuro format is more upright and compact, and the square model follows a rectilinear plan. Heater location differs across the range and may be internal, integrated or external. Those distinctions affect not only bathing space but also the supporting structure, pipe routes, ventilation, firebox access and the points that must remain reachable after the surrounding finish is installed.<\/p>\n<\/section>\n

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TERRACE1 to TERRACE7: seven fixed shells, not one variable tub<\/h2>\n

InGround Comfort is a family of finished shells intended for a separately engineered recess or terrace. The technical sheet is unusually specific: each TERRACE number has its own form, water volume, occupancy, heater position and outside dimensions. A change from TERRACE2 to TERRACE3 is not a cosmetic bench option; it is a different shell. Groundworks, structure, drainage and removable service access are outside the product and must be designed around the selected drawing.<\/p>\n

\n\n\n\n\n\n\n\n\n\n
TERRACE1<\/th>\nRound internal heater; 2\u20133 people; 1,200 L; 1,550\/1,750 mm inside\/outside; 970 mm outer height<\/td>\n<\/tr>\n
TERRACE2<\/th>\nRound Classic external heater; 6\u20138 people; 1,650 L; 1,800\/2,080 mm; 1,110 mm outer height<\/td>\n<\/tr>\n
TERRACE3<\/th>\nRound Wellness external heater; 6\u20138 people; 1,400 L; 1,800\/2,000 mm<\/td>\n<\/tr>\n
TERRACE4<\/th>\nRound Wellness internal heater; 6\u20138 people; 1,500 L; 1,800\/2,000 mm; 850 mm high<\/td>\n<\/tr>\n
TERRACE5<\/th>\nOval external heater; 1\u20132 people; 1,000 L; approximately 1,900 \u00d7 1,190 \u00d7 940 mm<\/td>\n<\/tr>\n
TERRACE6<\/th>\nRound Wellness external heater; 8\u201312 people; 1,550 L; 2,042\/2,240 mm<\/td>\n<\/tr>\n
TERRACE7<\/th>\nSquare external heater; 6\u201314 people; approximately 1,800 L; 2,008 \u00d7 2,008 mm inside and 2,200 \u00d7 2,200 mm outside<\/td>\n<\/tr>\n<\/tbody>\n<\/table><\/div>\n

Open the product technical sheet<\/a><\/p>\n<\/section>\n

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Choose a TERRACE number before an architect sizes the opening<\/h2>\n

TERRACE5 is the focused couple\u2019s Ofuro; TERRACE1 is the smallest round shell; TERRACE2 offers deep Classic geometry and the largest 1,800 mm water load; TERRACE3 and 4 compare external versus internal Wellness arrangements; TERRACE6 widens the round format; TERRACE7 gives square social seating. External heaters preserve bathing room and need a side service zone. Internal heaters compact the plan and occupy water space. No-heater variants are for separately engineered systems. The 6\u201318 kW electric options must be sized against the exact water volume and UK supply.<\/p>\n

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Decision<\/th>\nChoices currently selectable<\/th>\n<\/tr>\n<\/thead>\n
Inner diameter<\/th>\n1600 mm \u00b7 1800 mm \u00b7 1900 mm x 1000 mm (Ofuro) \u00b7 2000 mm \u00b7 2000 x 2000 mm<\/td>\n<\/tr>\n
Model (see technical sheets)<\/th>\n#TERRACE1 with snorkel wood burner (316 steel, chemical resistant) \u00b7 #TERRACE2 with external burner (316 steel, chemical resistant) \u00b7 #TERRACE3 with external wood burner (316 steel, chemical resistant) \u00b7 #TERRACE4 with snorkel wood burner (316 steel, chemical resistant) \u00b7 #TERRACE5 with external wood burner (316 steel, chemical resistant) \u00b7 #TERRACE6 with external wood burner (316 steel, chemical resistant) \u00b7 #TERRACE7 with external burner (316 steel, chemical resistant) \u00b7 No heater (TERRACE2) \u00b7 No heater (TERRACE3) \u00b7 No heater (TERRACE5) \u00b7 No heater (TERRACE6) \u00b7 No heater (TERRACE7)<\/td>\n<\/tr>\n<\/tbody>\n<\/table><\/div>\n<\/section>\n
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The recess must accommodate every selected accessory<\/h2>\n

An insulated cover, insulation and filtration are valuable, but their boxes, pipework and removal paths cannot be entombed below paving. Hydromassage and air massage add penetrations and pumps; LEDs and smart controls add low-voltage and network requirements. A heater lid or chimney guard reduces contact risk without replacing clearances. A tap and hose adaptor help direct discharge, but a 1,000\u20131,800-litre drain event must be designed into the landscape. Provide ventilation and removable panels on every equipment side.<\/p>\n

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Electric heater<\/h3>\n
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  • Power level and connection type. Default 6 kW. Select from the table and inform us separately<\/li>\n
  • Power increase to 9 kW or 12 kW<\/li>\n
  • Power increase to 15 kW or 18 kW<\/li>\n<\/ul>\n

    Advantages:<\/strong> Electric heat offers repeatable thermostat control, no fuel storage and a clean holding routine; 9\u201318 kW upgrades can shorten recovery when the selected water volume and electrical design justify them.<\/p>\n<\/section>\n

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    Type of lid<\/h3>\n
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    • With wooden round edge instead of fiberglass + Wooden lid instead of fiberglass (spruce)<\/li>\n
    • Insulated leather lid (recommended)<\/li>\n<\/ul>\n

      Advantages:<\/strong> A fitted cover reduces debris and heat loss; an insulated leather cover is normally lighter to handle and more thermally effective than a plain timber lid.<\/p>\n<\/section>\n

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      Insulation<\/h3>\n
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      • Wall insulation<\/li>\n
      • Bottom insulation<\/li>\n<\/ul>\n

        Advantages:<\/strong> Wall and bottom insulation reduce heat loss from the water vessel and are particularly useful for frequent use, exposed sites and electric temperature holding.<\/p>\n<\/section>\n

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        SPA<\/h3>\n
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        • Air bubble massage system<\/li>\n
        • Hydro massage system<\/li>\n
        • Sand filtration system<\/li>\n
        • 2 LED<\/li>\n
        • 4 LED (Recommended for 180 – 220 cm models)<\/li>\n<\/ul>\n

          Advantages:<\/strong> Air massage gives a gentle whole-tub effect, hydromassage provides firmer targeted jets, filtration supports retained-water use and LEDs improve evening visibility and atmosphere.<\/p>\n<\/section>\n

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          Smart SPA equipment add-ons (WiFi signal required)<\/h3>\n
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          • Smart app \u2013 voice controlled system kit for air massage<\/li>\n
          • Smart app \u2013 voice controlled system kit for water massage system<\/li>\n
          • Smart app \u2013 voice controlled system kit for sand filter<\/li>\n
          • Smart app \u2013 voice controlled system kit for electric heater (enables scheduled control, ON\/OFF)<\/li>\n<\/ul>\n

            Advantages:<\/strong> App control can schedule electric support and make filtration, air massage or hydromassage easier to prepare before a planned soak, with separate control applied only to the systems selected.<\/p>\n<\/section>\n

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            Inside color<\/h3>\n
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            • White (RAL 9001)<\/li>\n
            • Blue (RAL 5012)<\/li>\n
            • Gray (RAL 7015)<\/li>\n
            • Blue Pearl (RAL 7700)<\/li>\n
            • Gray Pearl (RAL 7730)<\/li>\n
            • Granite (RAL 9001)<\/li>\n<\/ul>\n

              Advantages:<\/strong> Liner colour lets the visible bathing shell coordinate with the garden and can make the water appear lighter, deeper or more neutral without changing the tub geometry.<\/p>\n<\/section>\n

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              Metal parts<\/h3>\n
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              • Metal fence on the chimney (heat protection)<\/li>\n
              • Stainless steel cover on the heater (for internal heater)<\/li>\n
              • Ash shovel and rake<\/li>\n<\/ul>\n

                Advantages:<\/strong> A chimney guard reduces accidental contact risk, a heater lid controls access around the firebox, and dedicated metal tools make ash handling and routine stove care more orderly.<\/p>\n<\/section>\n

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                Water release type<\/h3>\n
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                • Bottom water drain with a stopper (included)<\/li>\n
                • External water tap<\/li>\n
                • External water tap + Quick adapter for garden hose set (12.5mm & 15mm)<\/li>\n<\/ul>\n

                  Advantages:<\/strong> An external tap gives better control over discharge, while the quick hose adaptor helps route water away from foundations, neighbours and soft landscaping.<\/p>\n<\/section><\/div>\n<\/section>\n

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                  The seven volumes and heater positions cannot share one heating promise<\/h2>\n

                  The family spans 1,000\u20131,800 litres and several heater positions. TimberIN\u2019s general wood-fired guidance of 2\u20133 hours warm and 4\u20136 hours cold is therefore context, not a specification. Electric support from 6 to 18 kW changes theoretical heat-up dramatically and may require a much larger supply. Ask for the chosen TERRACE water volume, heater output and estimated losses in writing. Insulate the recess without blocking ventilation, use the cover during warm-up and keep every heater accessible for commissioning.<\/p>\n<\/section>\n

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                  Design a maintainable installation, not a sealed box<\/h2>\n

                  Use the selected model drawing to coordinate the load-bearing structure, clear opening, access hatch, drainage fall and all services. Earthwork, retaining construction, terrace framing, crane position and site waterproofing are normally project responsibilities rather than parts of the tub price. Allow ventilation around equipment and a route for removing heaters, pumps or pipework in the future. Surface water should drain away from the recess, and any leak should be visible and recoverable. The installer must also preserve safe chimney and firebox clearances where wood heating is selected.<\/p>\n<\/section>\n