Stone vs acrylic bathtub: how do they compare?

How much heavier is a stone tub?

A solid stone tub weighs about 1,100 to 2,500 lb (500 to 1,130 kg) empty. An acrylic tub weighs 60 to 120 lb; one consumer guide gives around 75 lb on average. A typical 67 by 31 by 22 in oval marble tub with 2.5 in walls weighs about 1,150 lb empty and about 1,960 lb filled with a 200 lb bather.

Our full weight breakdown is in the stone bathtub weight guide.

Does a stone tub keep water warmer than acrylic?

Once warm, yes. Marble has a specific heat of 880 J/kg per degree C, and a marble tub has many times the mass of an acrylic one, so it stores far more heat. But marble also conducts heat roughly ten times faster than acrylic, with a thermal conductivity of 2.08 to 2.94 W/(m K) against 0.2 for acrylic. A cold stone tub draws heat from the first fill and feels cool to the skin until it warms through.

Acrylic feels warm immediately and holds heat fairly well. Read the warm-water guide for the full comparison, including pre-warming a stone tub.

Which lasts longer, a stone or an acrylic bathtub?

Stone is a solid material rather than a thin shell, so there is no surface layer to fade or wear through. An acrylic tub usually lasts about 10 to 15 years before it fades and scratches noticeably, according to one home guide, though another puts quality tubs at 10 to 25 years and budget tubs at 8 to 10.

Both can be damaged. Acrylic is soft and is harmed by abrasive pads and by solvents such as acetone. Natural marble and onyx etch when acids sit on them. See stone tub care for the cleaning routine.

How are scratches and chips repaired?

Acrylic repair is a homeowner job. Light scratches buff out with acrylic polish or fine wet sandpaper followed by compound, and small chips can be filled with a repair kit.

Stone repair is a trade job. Etching on polished marble is re-honed or re-polished by a stone restorer. One vanity guide puts re-honing a vanity-sized surface at $200 to $600; a tub is a larger surface and costs more. Small chips can be filled. Because the stone runs through the wall, a repair does not expose a different material underneath.

Is a stone bathtub harder to install than acrylic?

Yes. A stone tub needs a delivery plan, a floor assessment and often reinforcement, while an acrylic tub is a normal load that one or two people can carry. An acrylic tub filled with water and a bather is a normal load for a residential floor. A filled stone tub is not. Our model of the 67 in marble tub puts about 170 psf on its footprint, against a typical residential floor live load of 40 psf. A structural engineer may call for reinforcement or a different location.

Check with a structural engineer before ordering, and a licensed plumber for drains and supply. Every Pietra Fonte quote gives exact dimensions and weight so they can do that.

How do the two compare side by side?

Which is the better choice for your bathroom?

Choose acrylic for a budget project, an upper-floor bath, a rental, or a tub that will be replaced in a decade. Choose stone when the tub is the centerpiece, the floor can carry it, and you want a natural material that lasts.

If you are weighing stone against engineered options too, see stone resin vs solid stone. To browse, start with stone bathtubs or ask us about a bespoke piece.