Toilet rocking or loose at the base — Madrid, Madrid

A toilet that rocks or moves when you sit on it is more than an annoyance — it signals a failing seal between the toilet and the drain pipe, and every rock works the wax ring loose a little more. The wax ring is a thick wax gasket that sits between the toilet horn and the closet flange bolted to the floor; it creates a watertight, gas-tight seal. Once the seal breaks, sewer gas seeps into the bathroom (you'll smell rotten eggs), and dirty water can leak beneath the toilet with every flush, silently soaking the subfloor. Over months, this hidden moisture rots wooden subfloors and can lead to a much more expensive repair. The most common causes are: loose or corroded closet-flange bolts (the simplest fix — just tighten or replace them, $0–$20 in parts), a broken or rusted closet flange that no longer holds the bolts securely ($75–$200 to install a flange repair ring or replace the flange), an uneven floor where the toilet doesn't sit flat (shimming with plastic toilet shims and caulking costs under $30), or a rotted subfloor beneath the flange from a long-term leak ($300–$800 to cut out and replace the damaged section). In every case, the wax ring should be replaced whenever the toilet is pulled — a standard wax ring costs $5–$10, and a premium wax-free gasket runs $15–$30. A licensed plumber can pull the toilet, inspect the flange and subfloor, replace the seal, and reset the toilet in about an hour ($150–$300 for the service call plus parts). Don't delay this repair — the longer a rocking toilet goes unfixed, the greater the risk of subfloor damage, sewer-gas exposure, and a potential sewage leak beneath the floor.