Shower and bathtub plumbing

A mat of hair bound together by soap scum, sitting in and just past the trap. Soap residue coats the pipe wall and gives hair something to catch on, and it builds over months. Pull the stopper out first. A large share of slow showers clear completely at that stage, for nothing. If it slows again within weeks, the coating extends further down the branch and needs proper cabling.

No. They do a poor job on a hair-and-soap mat, they sit in the trap where the next person working on the pipe will meet them, they damage older pipe and rubber seals with repeated use, and they attack plated waste fittings. A $20 hand auger from a hardware shop is more effective and harmless.

A flush draws cold water, pressure on the cold side drops, and the mix at your valve shifts hot. Old two-handle valves have no defence against it. A pressure-balancing valve holds the hot-cold ratio through pressure changes and a thermostatic valve holds an actual temperature. If you already have a single-handle valve and it still swings, the internal spool or cartridge is worn. A cartridge job through the trim plate.

Test one thing at a time. Run the shower with nothing else on for ten minutes. Then fill the tub and let it stand without draining. Then drain it. Then spray the walls without wetting the floor. Then check with everything off. Whichever test brings the stain out tells you whether it is the pan, the drain, the overflow, the tile or a pressurised supply line, and a leak that continues with everything off is the urgent one.

Usually not. Most complaints are fixed by a cartridge replacement done through the trim plate with no demolition. Only a cracked or eroded valve body, a brand change, or a two-handle-to-single conversion needs the wall opened, and that can often be done from behind through a closet or adjoining room. If tile must come out, ask for a neat access panel to be fitted so the next repair is a twenty-minute job.

Probably not. Descale the head first, then check whether the small plastic flow restrictor inside it is blocked, then have the valve cartridge checked, then test static pressure at an outside hose bib. Buying a new head first is the standard mistake, and if whole-house pressure is under 40 psi, the cause is the regulator or the supply pipe, and no head will fix it.

No, it is capacity. A 40-gallon tank covers roughly one ten-minute shower plus part of another, and recovery on an electric tank is about 20 gallons an hour. The answers are a larger tank, a faster-recovering gas unit, or tankless. Staggering showers by half an hour also works, if less popularly.

More than swapping the fixture. The drain goes from 1.5 inch to 2 inch and usually moves, so the branch drain and trap are replaced. The valve moves from around 28 inches to around 48 inches, so that wall is opened. And the waterproofing changes completely. A tub flange does the work in a tub, while a shower needs a full pan and wall membrane. Budget the tiling and waterproofing separately; it is usually the larger cost.

Almost certainly the overflow gasket. The rubber seal behind the overflow plate at the head of the tub. It is a very cheap part, and it drips into the ceiling below every time the water reaches that level. People live with it for years and pay for the ceiling instead.

Only if the leak is genuinely surface water through failed grout. If the waterproof membrane under the tile has torn or was never lapped correctly at the corners, water is bypassing the tile entirely and regrouting changes nothing. The test is whether spraying the walls produces the leak while running the shower normally does not. A failed pan liner means the shower floor has to be rebuilt.