Of all the rooms in your home that should be protected against excess moisture and potential water leaks, the bathroom is the most important. Steam from the shower, as well as water leaks in any of the pipes behind the walls, can mean water damage and resultant mold or mildew. Unfortunately, it's not always easy to know when your bathroom needs new or additional waterproofing (from professionals such as Westside Sealants Pty Ltd), as water damage often starts behind the walls or under the floors. Note a few common signs to look for so you know when it might be time to call a contractor and have your bathroom building materials inspected.
Warped or bubbling walls
When drywall is exposed to too much moisture, it begins to warp and then potentially bubble. If you note that any bathroom wall seems slightly curved and especially if you notice bubbles of any size forming on the walls, this is often a sign that the material is absorbing moisture from either the front or the back. You would need to find the source of this excess moisture and water and then also typically replace the damaged drywall with something more sturdy and stable.
Consistent mold or mildew on bathroom surfaces
Your bathtub is likely to get occasional mold and mildew from water that is left over from a shower. However, if you notice consistent mold or mildew, even if you clean regularly, this often means that the mold starting from underneath those tiles rather than forming from on top of the surfaces. Note if there are cracks in the tile or grout, or if the grout itself seems loose and brittle. If so, this often means that steam and water droplets are getting in beneath the tile surfaces and allowing mold and mildew to form, or there is a water leak behind the walls.
The creaking of floorboards under the bathroom may mean that they have warped due to the house setting, but if they feel soft or spongy, this often means water damage to the boards. The tile may have also come loose because of the extra moisture under the surface so that it feels soft when you walk across it, as it shifts and moves out of position. This water damage can be caused by a water leak in the pipes that is dripping onto the floor area or gaps in the tile and grout, allowing steam to seep into the area under the tiles, as mentioned above.