Bath Types Compared: Acrylic, Steel, Stone and Freestanding

Weights shown are the bath empty, then a realistic filled weight with an average adult in it. That combined figure is what your floor has to carry.

A standard 1700 mm acrylic bath on a typical upstairs timber floor is fine. A cast iron or stone resin freestanding bath frequently is not, particularly in older properties or where joists span a long distance.

The load is also concentrated. A freestanding bath sits on a small footprint rather than spreading weight across a frame and along the wall.

We check joist size, span and direction at survey when a heavy bath is proposed. Where strengthening is needed, it is straightforward and we price it as a visible line rather than discovering it mid-job.

First floor bathrooms above a garage or a bay window need particular attention, because those floor structures are often lighter than the rest of the house.

1700 x 700 mm is the UK standard and the size most bathrooms are designed around.

1500 or 1600 mm baths free up valuable space in smaller rooms without feeling cramped for most adults.

1800 x 800 mm feels genuinely luxurious but needs the room to support it and a hot water system that can fill it.

A freestanding bath needs clearance all round to look right and be cleanable, realistically 100 mm behind and 150 mm each side as a minimum.

Shower baths need the wider end at the tap or shower end, which sometimes conflicts with where the existing plumbing sits.

A flat-bottomed shower bath is far safer and more pleasant to stand in than a standard tapered bath, and costs very little more.

The bath must be fully supported and level. A bath that flexes underfoot will break the silicone seal within months, and that is the most common source of the leak that appears in the ceiling below.

A hinged glass screen beats a shower curtain for splash control and looks considerably better, though it needs the bath to be positioned so the screen can swing clear.

Tiling should run behind the bath edge with a proper upstand and sealant detail, not simply be butted and siliconed on the surface.

Acrylic feels warm immediately and holds heat reasonably. Steel feels cold when you get in and then holds heat well once warmed.

Stone resin and cast iron hold heat best by a wide margin, which is exactly what you want in a bath you intend to lie in for an hour.

Insulated bath kits and simply packing the void under an acrylic bath make a noticeable difference for very little cost during installation.

If long soaks matter to you, check your hot water system can actually fill the bath at temperature. An 1800 mm bath on a small combi is a slow and disappointing experience.