A natural stone bathtub is a freestanding soaking tub carved by hand from a single river boulder or marble block, with no seams, liners or joints. Finished tubs weigh 1.1 to 2.1 tonnes (2,400 to 4,600 lb) empty, so before buying confirm three things: that your floor can carry the load, that the crate can physically reach the bathroom, and where your drain and tub filler will sit.
What makes a stone bathtub different
Most "stone" tubs sold online are stone resin: crushed mineral mixed with polyester or acrylic and poured into a mold. A true natural stone bathtub starts as a boulder or quarried block that an artisan hollows and shapes over several weeks. Nothing is glued or cast. The result is heavier and visibly unique, because no two boulders share the same color, grain or outline.
- One piece, no seams. There is no joint to fail and no liner to yellow or crack.
- Thermal mass. Stone absorbs heat and releases it slowly, so bath water cools more gradually than in a thin-walled tub.
- Sculptural presence. Architects place a stone tub in the center of a room or in front of a window, not against a wall.
- Weight. The trade-off: a stone tub is a structural decision, not just a plumbing fixture.
Browse the current pieces in our stone bathtubs collection; each listing shows the exact weight and dimensions of that individual tub.
River stone (volcanic basalt) vs. travertine marble tubs
Marmer Butik tubs come from two materials, both carved in Indonesia's volcanic islands.
River stone bathtubs are made from basalt boulders rounded by volcanic rivers over thousands of years. The outside is usually left with its natural skin, mottled gray to charcoal, while the interior is honed smooth and sealed. Basalt is dense and very low in porosity, so it resists staining and suits wet rooms and outdoor settings.
Marble and travertine bathtubs are cut from quarried blocks in cream, beige, white or honey tones, with veining or the fine pores typical of travertine. They are shaped smooth inside and out for a classical, Mediterranean look, and being slightly more porous they need resealing about once a year.
| Feature | River stone (basalt) | Marble / travertine |
|---|---|---|
| Color | Gray, charcoal, black | Cream, white, beige, honey |
| Exterior finish | Natural boulder skin or honed | Honed or polished |
| Porosity | Very low | Low to medium |
| Sealing | Every 2 to 3 years | Yearly |
| Style | Organic, wabi-sabi, spa | Classic, Mediterranean, Ibiza |
Weight and floor loading
Read this section with your builder or engineer. Natural stone bathtubs weigh 1,100 to 2,100 kg empty:
| Model | Material | Empty weight |
|---|---|---|
| BRS03 | River stone | 1.1 t (approx. 2,425 lb) |
| BM01 | Marble | 1.4 t (approx. 3,085 lb) |
| BRS01 | River stone | 2.1 t (approx. 4,630 lb) |
To the empty weight, add 250 to 350 liters of water (250 to 350 kg) and one or two bathers (80 to 180 kg). A BRS01 in use can therefore approach 2.6 tonnes resting on roughly one square meter of floor. Residential floors in the US, UK and EU are typically designed for a distributed live load of about 1.5 to 2 kN/m² (30 to 40 psf), an order of magnitude below a filled stone tub.
- Ground floor on a concrete slab-on-grade: usually suitable, but confirm slab thickness and that there is no void or crawl space beneath.
- Upper floors or timber-joist floors: require an engineered solution, typically a steel beam or doubled joists under the tub footprint, transferring load to bearing walls.
Consult a licensed structural engineer with the tub's weight, footprint and position before you order; we send a spec sheet for any tub on request.
Dimensions and comfort
Typical freestanding stone tubs are 170 to 200 cm long (67 to 79 in), 80 to 100 cm wide and 55 to 70 cm high. Walls are 8 to 15 cm thick, so check interior length and depth, not just the outer footprint.
- Single soaker (170 to 180 cm): one adult lying back with legs extended.
- Double or oversized (190 to 200 cm): two adults facing each other, or one person with full stretch.
- Ofuro-style deep tubs: shorter but deeper (interior depth 50 cm or more), for seated soaking with water to the shoulders, inspired by Japanese bathing.
Plumbing
Stone tubs have no tap holes drilled in the rim. Water comes from a floor-mounted tub filler standing beside the tub, with the supply lines stubbed up through the floor before the tub is placed. Choose a filler whose spout sits 10 to 15 cm above the rim; see matching fillers in our faucets and fixtures collection.
The drain is a standard 1.5 in (40 mm) outlet carved into the base; its exact position differs from tub to tub, so give your plumber the spec sheet before roughing in the waste pipe. Most stone tubs have no overflow; a floor drain in a wet-room layout is the usual safeguard.
Delivery and installation
Every tub ships bolted inside a reinforced timber crate on a pallet. Pieces over 60 kg, which includes every tub, are sold by quotation, with freight and import duties calculated for your address. Smaller items such as stone sinks ship by FedEx with duties included (DDP), so there is nothing to pay on arrival.
- Sea freight: the economical option, typically 6 to 10 weeks port to port plus customs clearance and last-mile delivery.
- Air freight: 1 to 2 weeks, sensible for lighter tubs on tight deadlines.
- Site access: delivery is curbside or to the loading dock. You need a forklift, crane or pallet jack to unload, then riggers to move the tub through doorways (crates are about 100 to 120 cm wide) onto the reinforced floor.
- Setting: the tub is bedded on flexible mortar or silicone and should be the last large item placed in the room.
To get a quote, send the model you want and the full delivery address through our contact page. Architects, designers and hospitality buyers ordering several pieces can apply for trade pricing on the wholesale page.
Care
Rinse after each use and wipe dry to limit mineral spots. Clean with a pH-neutral stone soap; never use vinegar, bleach, citrus or abrasive powders. Reseal with a penetrating stone sealer every 2 to 3 years for basalt and yearly for marble. Avoid strongly dyed bath products and wipe up essential oils promptly on lighter stone. With this routine a stone tub keeps its finish for decades.
Why buy from Marmer Butik
Natural stone is unique. That is why we handle every piece individually — and you know exactly what you will receive before you commit.
- Photos, videos and measurements of the exact piece: Before you order, you receive photos, videos and the real measurements of every selected piece. You approve the piece you will receive, not a catalog photo.
- Selected and inspected one by one: Every sink, bathtub, pedestal and statue is chosen and inspected individually at origin: finish, polished interior and drain opening checked before shipping.
- Premium quality: Solid natural stone, hand-carved from a single block by artisans in Bali and Java. No coating to peel — built to last for decades.
- Safe, secure packaging: Every piece is packed individually with reinforced protection — for container orders, in its own wooden crate matched to the packing list.
- Direct importer since 2013: Over a decade of direct relationships with the workshops, no middlemen. We handle crating, export documents and shipping to your port or door.
- Dedicated specialist: One specialist follows your order from quote to delivery, in English, Spanish or Portuguese, with a reply within 24 hours on business days.
Frequently asked questions
How much does a stone bathtub weigh?
A hand-carved natural stone bathtub weighs between 1,100 and 2,100 kg (2,400 to 4,600 lb) empty. Marmer Butik tubs range from 1.1 t (BRS03) to 2.1 t (BRS01), before water and bather.
Can a stone bathtub go on an upper floor?
Only with an engineer's sign-off. A filled stone tub concentrates 1.5 to 2.5 tonnes on about one square meter. Ground-floor slabs are usually fine; timber upper floors normally need added steel or doubled joists.
What is the difference between a river stone and a marble bathtub?
River stone tubs are carved from dense volcanic basalt boulders, usually dark gray with a natural exterior and honed interior. Marble and travertine tubs are lighter, veined, smooth all around and slightly more porous, so they need more frequent sealing.
How is a stone bathtub delivered internationally?
Each tub is crated on a pallet and shipped by sea or air freight. Because tubs exceed 60 kg, they are quoted individually with freight and import duties based on your delivery address. Standard stone sinks ship by FedEx with duties included.
Do stone bathtubs keep water warm?
Yes. Stone has high thermal mass: it absorbs heat in the first minutes, then returns it slowly, so water cools more gradually than in an acrylic tub. Pre-warming the tub with hot water strengthens the effect.
