+++CLEANING ROUTINES
Tub surrounds and shower enclosures require to remove the accumulation of water deposits and soap scum to prevent mildew from happening.  You can remove this with water and soap or one cup of vinegar in 1 gallon of water and also store products work just as well.  Cleaning your tiles two to three times a month will keep them looking shiny and prevent mildew.

+Bathroom, kitchen and laundry wall tiles need only be cleaned with a mild detergent or household cleaner. There are really only two rules to follow.
Don't use an abrasive cleaner such as a powder or gritty cream. These will cause minute scratches in the surface and make the tiles harder to clean the next time.
Clean tiles regularly so dirt doesn't build up. Tiles are a great product, but they don't stay clean by themselves.
+The same basic rules apply to floor tiles. Don't use abrasive cleaners, or any sort of polishes or additives. They will only build up and cause problems later. Wash you tiles regularly using hot clean water and a little neutral (not acidic or alkaline) soapless household cleaner.
It is possible that a very thin film of grout has been left on the surface of the tiles making them appear dull. In this case, we recommend the use of Aqua Mix Heavy Duty Tile & Grout Cleaner (must be used per manufacturer's written instructions) making sure that you try it out first on a less noticeable area (behind a door or cupboard for example), to ensure it does not damage the tile and make sure you rinse the floor thoroughly with clean water after treatment.
+Tiles can become scratched by grit, especially high glazed ones. To minimise this, ensure a door mat is used just inside any exterior door. If you have very high glazed floor tiles in your bathroom, avoid walking on them with harsh footwear.
One or two tiles in your floor may become chipped or cracked. Please make sure you have kept some spares, as tile batches vary in colour and fashions come and go, so it's very unlikely that you could ever match your tiles up a few years later.

+Marble and granite are easier to maintain t. Warm water, mild dishwashing liquid and a soft cloth clean up most spills .

+Granite is a worry-free surface, requiring few  precautions. It is extremely durable, stain resistant and easy to care for. Hot kitchen ware won't damage it. It won't chip, crack or scratch under normal use. Cutting boards are recommended when slicing bread, meats or vegetables to protect your knives from becoming dull.
+Marble isn't quite as worry-free as granite. It has a softer, less stain-resistant surface than granite. Spills should be wiped up immediately; Marble is especially susceptible to damage from citric acids, alcohols and oils.

+++ASSES THE DAMAGE
Always check for damages  such as cracked grout joints, water spots, and damaged tiles. This damages could create more structural problems.

+An important note on seasonal movement. As the walls of your house move against each other, the seal between the bath, shower base, basin and tiles may be broken. This may also occur on the vertical internal corners. You may have put a flexible sealant in, but this can become brittle or come away with age and must be replaced to ensure moisture doesn't leak through.
This can have disastrous consequences. This is as much a maintenance job in a house as repainting timber surfaces. When you see that the sealant is lifting away, replace it as soon as possible. To replace it, remove the whole lot, then thoroughly dry the joints using a hairdryer or similar, wipe the tile faces clean with a little metholated spirits on a cloth and then simply reseal.

+++WATER PROBLEMS
Obvious sources are damaged sealant or caulk, exposed fixtures or joints, broken gaskets, and or packing material around faucet.  If you suspects water damages the only way to check is to remove a tile to see if there is damage to backerboard or subfloor.