Which basin should I choose — pedestal, semi-pedestal, wall-hung or countertop?

Almost every loose basin is a load-path problem, not a fixing problem — someone hung a heavy ceramic bowl on two bolts into plasterboard with nothing behind it. Because the pedestal or the shroud looks like it is holding the basin up, the situation feels safe right up until it fails. The drawing shows what is really carrying the weight in each of the four arrangements.

Step by step

1. Find out what your wall is before you look at basins.Knock it and check with a detector. Solid masonry will take a resin anchor or a long expansion plug and carry almost anything. Dot-and-dab plasterboard needs a fixing that reaches the masonry behind the dabs, not one that grips the board. A stud wall needs noggins between the studs at the fixing height, and if there are none, that decides your basin type.
2. Understand the full pedestal.The bowl bolts to the wall and a ceramic pedestal stands on the floor beneath it, hiding the trap and the supply pipes. It is the most forgiving type because the pedestal props the bowl and takes some of a downward push, and it is the most tolerant of an imperfect wall. It also makes cleaning the floor around it awkward and it fixes the basin's height.
3. Understand the semi-pedestal.A shroud hangs off the underside of the bowl and does not touch the floor at all. It hides the trap while leaving the floor clear, and it looks lighter in a small room. But nothing is propping anything: every gram of the basin's weight, and every time somebody leans on the front rim, goes into the wall fixings. This is the type that most often comes loose, and it is the one that most demands a solid wall.
4. Understand the wall-hung basin on a frame.A steel frame inside a stud wall or fixed to a masonry wall, bolted to the floor and tied back to the structure, with threaded rods passing through the finished wall to carry the basin. This is the only arrangement where the load path returns to the floor without depending on the wall's own strength, and it is the correct answer for a heavy basin on a stud wall. The frame has to go in before the wall is boarded and tiled.
5. Understand the countertop basin and vanity unit.The bowl sits on or in a worktop carried by a floor-standing or wall-hung unit. The unit carries the basin, and the wall fixings only hold the unit. Countertop basins rarely come loose; the units under them sometimes do. This is also the only option that gives you storage, which in a small bathroom is worth a great deal.
6. Set the height for the people using it.Basin height is decided by the tallest regular user's comfortable washing height, and a rim set too low is the commonest bathroom regret. Children are better served by a step than by a low basin, because the low basin is permanent and the child is not.
7. Check the tap hole arrangement.No holes means a wall-mounted or worktop-mounted tap. One hole takes a monobloc mixer. Two or three holes take pillar taps or a three-hole mixer. Confirm this matches the tap you want before ordering either.
8. Check whether the basin has an overflow.It decides which waste you need — a basin with an overflow needs a slotted waste so the overflow can discharge, and one without needs an unslotted waste. Fitting the wrong one either leaves the overflow useless or leaves an open slot leaking into the cabinet.
9. Think about the trap and the space behind.A wall-hung or countertop basin often needs a bottle trap or a shallow trap to fit in the space available, and a bottle trap blocks more readily than a P-trap. On a semi-pedestal, the shroud has to clear whatever trap you fit.

Common mistakes

• Hanging a semi-pedestal or wall-hung basin on plasterboard with no support behind — The pedestal or shroud is not carrying anything, so the entire load and every lean on the front rim is on two fixings in a board.
• Assuming the pedestal is holding the basin up — It props and it hides pipes. A basin whose wall bolts have failed will still feel supported by the pedestal until the moment it does not.
• Choosing a basin before checking the tap hole arrangement — Basins and taps have to match on hole count, and a redundant hole in ceramic cannot be filled invisibly.

Questions people ask