Bespoke ice baths: from a sketch on a napkin to a one-use mould

Six steps, and where you decide

The sequence is the same for a round terrazzo tub in a Bandung garden and for a hotel wet area in Nusa Dua. Only step three changes length, because the further a design sits from the catalogue, the more of it has to be seen with your own eyes before anything is cast.

1. Survey and heat load. Area size, floor construction, where the midday sun lands, distance to water and power. Out of that comes a load in watts and a chiller size, and only then can shape be discussed. Free, including outside Java.
2. Concept and sections, 3-5 days. Two or three alternatives with volume, seat height, rim height and the outdoor unit position. At this stage we still change anything at no cost.
3. Physical samples. A 20 by 20 centimetre terrazzo chip, an oiled teak offcut, or a steel plate in your chosen finish, posted to your address. We never ask anyone to approve a colour from a screen.
4. Final working drawings. Sections at 1:20, pipe layout, electrical points and rim details. Where there is an architect, this goes out as DWG so it can be overlaid on their own file.
5. Mould and production. A timber mould is built for your shape and used once. For terrazzo: the pour, 14 days of curing, then three wet-grinding passes.
6. Installation and cold test. Identical to a catalogue tub, and set out step by step under installation and cold test.

The 40 per cent deposit is invoiced only after step four. Until the working drawings are approved you have paid nothing and we have cut no timber.

Nine terrazzo colours, and what a tenth costs

Our terrazzo is cast from Tulungagung marble aggregate with white cement in nine base mixes we have poured hundreds of times and can therefore guarantee. Chip size runs 4 to 12 millimetres and the aggregate-to-cement ratio is 2.4 to 1. After casting, the body cures for 14 days and is then wet-ground in three passes — coarse, medium, fine — with the rim finished by hand because no machine can follow an inside curve.

If you want a colour we have never cast — green Sukabumi aggregate in grey cement, say — we cast a single 20 by 20 centimetre sample and grind it to completion first. That costs Rp 2.4 million and five days, and it comes off the tub price if the order proceeds. We will not mix an untried colour straight into a shell worth tens of millions, and the same rule applies to every material on the products page.

Shapes that are not rectangles

About one tub in four we build is not a rectangle. The most requested are an oval for a garden and an L for a tight terrace corner. Every shape is possible to cast; three things change the moment the straight sides disappear.

• Volume grows faster than people expect. An oval 1.9 by 1.1 metres with a 76-centimetre working depth holds about 520 litres, not the 400 most people estimate. Those extra 120 litres can move the chiller up a size, so we re-run the chiller calculator before the shape is locked.
• The mould costs more. A curved mould is built from laminated thin plywood layers and adds 15 to 25 per cent to the shell price.
• Internal seats have to be cast in. A step or a bench inside the tub is poured as part of the body, never bonded on afterwards, and that adds three days plus Rp 3.2-6.8 million.
• Inside corners cannot be sharp. Our minimum is a 60-millimetre radius on vertical corners, because a sharp corner is where shrinkage cracking begins.

The plant space nobody draws until it is too late

The question that almost always arrives late is where the pump, the filter and the ozone unit are going to live. On a freestanding tub they hide inside the base frame. On a sunken tub or a solid stone body they need a space of their own, and that space has to be on the architect's drawing before the floor is finished, not hunted for afterwards.

Working with architects and main contractors

Roughly 30 per cent of our bespoke work arrives through an architect, and those projects run most smoothly, because the structural decisions get made before the floor is poured. What we put on their desk is always the same package: the tub section in DWG, filled weight per square metre, pipe and drainage positions, electrical demand in amps, and plant room dimensions. All of it is free and none of it is binding.

What we ask from them is equally simple: the structural plan so the tub can sit over a beam, the finished floor level so the rim lands flush with the deck, and the nearest drainage point. With those three in hand from the start, a sunken tub can be cast at the same time as the floor, saving about two weeks and all the demolition that otherwise follows. On larger schemes we come in as a specialist subcontractor, which is described under custom wellness areas.

Extra time and extra cost, written out

The figures below are additions to a catalogue tub in the same material and volume. Base prices per material are on the pricing page, and every one of these appears as its own line in the quotation rather than being melted into one large number.