As contemporary residential designers in the Northern Beaches we have detailed the different material options available for bathtub selection.
Enamelled Cast Iron
Cast iron tubs have an enamelled porcelain coating. They are losing market share to enamelled steel tubs due to the cost of iron and their excessive weight that may require engineering upgrades. They do however have the highest heat retention and less chance of chipping since the enamel is thicker on a cast iron tub. If major surface damage does occur, a professional re-surfacer will be needed, but this is economical and easily accessible.
Scratch / Chip: ★★★★
Heat Retention: ★★★★☆
Cost: $$$$ - $$$$$$
Very similar to the cast iron bath, but with a thinner porcelain coating which is more susceptible to crack damage. The repair process is the same as the cast-iron tubs though, which is easy and economical. Purchase prices for steel tubs are cheaper than cast-iron as the steel is stamped into shape rather than molten metal poured into a mould. They are also much lighter and therefore easier to transport, though still double the weight of acrylic.
Scratch / Chip: ★★☆
Heat Retention: ★★★☆
Acrylic bathtubs have come a long way in the last few decades and are now, durable, cheap options with the largest range of shapes and formats due to their ability to be easily formed. Abrasive cleaners will damage the surface, but they are otherwise very hardy and not at risk of chipping like porcelain enamelled tubs. If damage does occur, DIY options are long, tedious and can be toxic. Professional repair is harder to find than porcelain resurfacing, probably because of demand. In Australia, fibreglass is not as readily available as it once was, now superseded by the superior heat retention, anti-slip and durability properties of acrylic.
Scratch / Chip: ★★★★
Heat Retention: ★★☆
Composite, otherwise known as cast-polymer, is a similar product to solid surface countertops. It is made from ground up minerals and stones mixed with a resin. A realistic appearance of natural stone can be achieved for a much cheaper price, making them quite striking. Any scratches are easily buffed out, but the main issue with this product is wearing of the Gel coat that protects it. This gel coat makes the surface slippery and is scratched easier than acrylic.
Scratch / Chip: ★★★
Heat Retention: ★★★★