The toilet flange anchors to the subfloor, usually with wood screws or cement screws, but most of it should sit above floor level at full height. When a flange is flush with the subfloor or below it, it can lead to the creation of leak paths.

Dry rot or severe water damage may warrant a replacement, but you don’t always need to replace damaged subflooring. If your subfloor has warped because it was installed incorrectly, you can sometimes shim the panels (in other words, add a thin, wedge-shaped piece of wood to level the surface). If your subfloor bows upward, you may be able to sand it down at the joist so it’s level, depending on the extent of the damage.

Yes, carpeted stairs are generally considered safer than stairs with hard surfaces like wood, vinyl, or tile. Carpet provides more traction, which helps reduce the chances of slips and falls, and its cushioning can lessen the severity of an injury if a fall does occur. Hard surfaces often lack the friction needed for a secure tread and can be quite slippery.

However, it's worth noting that some carpets can also be slick, particularly if they are brand new, dirty, or made from certain materials. If any stair surface feels too slippery, traction treads can be added to most materials to increase grip and improve safety.

When deciding whether to repair or replace your carpet, consider its age, the extent of the damage, and its location. It's often best to replace the entire carpet if the damage is extensive, such as large sections needing replacement, or if it's caused by water, which can lead to mold problems. Similarly, if your carpet is nearing a decade old, replacement is likely the more logical choice. On the other hand, consider repairing your carpet if the damage is localized to one spot, like minor rips or snags, the carpet is still relatively new, or the damage is in a low-traffic area of your home.