here are two main reasons why there is always a grout line with Ceramic or Porcelain tile. 1.) Ceramic & Porcelain Tiles are printed, glazed, cut then cooked in a kiln. During the firing process the tiles shrink, and not consistently, leaving the tile not true to square. The closer the tiles are installed the more the grout line will "fishtail". Installers will enlarge the grout line (typically 3/16") to compensate, ensuring that the grout line is straight, giving the impression that the tile is perfectly square. 2.) Concrete slabs are not perfectly level. Typical Ceramic & Porcelain tiles are installed with an adhesive called Thin set, which true to it's name is a very thin setting material. The Thin set can only compensate up to a 1/2" difference of the slab. The closer the tiles are installed to one another the more the tile will be elevated or lower than the majority of the floor creating a "high or low" which is a trip hazard. A good installer will enlarge the grout line enabling the tile to be slightly pitched depending on the contours of the slab.
Rectified is a fancy term describing a Porcelain tile that was cut after the kiln. This process allows the tile to be true to square, enabling the installer to tighten the grout lines (approx 1/8"). Most good installers will still open the grout lines to cope with the concrete slab. The true benefit of a "Rectified" tile is to do a marble or mud setting.
Marble and other Natural stones are quarried. They are products of mother nature and subject to large variations. Porcelain and Ceramic tiles are manufactured in a factory and will have a definite repeating pattern. Most tiles in production these days are made to emulate one type of stone or another, but there is always something lost in translation between what natural stone looks like and what a team of designers think natural stone looks like.
Tile is installed with an adhesive called "Thin set" and is a very thin layer of adhesive, generally 3/8" to 5/8". This material will only allow an installer to compensate for slight inconsistencies of the concrete slab. Generally this installation will yield a 1/8" or larger grout joint Marble is also a "Thin set" application but only after the installer has leveled out the slab using a mortar mix (Mud). A marble installer must be correct on every piece installed from levelness to a 1/32" difference in cutting. This type of installation only allows a 1/32" expansion joint between the stone which is then filled with grout
There is no right or wrong answers to this question. There are many factors to consider when selecting a floor. Lifestyle, Preference, and base cost of your home are just a few.
Both stone and tile floors should be washed regularly with plain water and elbow grease. When you use a chemical to clean your floor and do not rinse your floor thoroughly after, that chemical can bond with the porous nature of grout and stone. It is recommended for a weekly cleaning just to use plain water for either any type of hard surface flooring and steer clear of any acid or astringent type cleaner. This includes simple acids like Vinegar or lemon fresh cleaners. Natural stones should be clean once or twice a month with a neutral base cleaner and rinsed. Natural stone floors also require routine cleaning and sealing from a licensed and insured professional. Tiles should be cleaned once or twice a month with a soft detergent and rinsed.
All natural stones are porous to some degree. That porosity allows liquids and micro particles to permeate the stone. A sealer acts much like a wax you would put on your car, preventing liquids to pool and set into the stone. Please note that sealers are not a permanent part of the stone. Most residential clients will need to have their floors resealed, typically every 3 to 5 years.
Ceramic tiles are made of clay bisque. They are printed or dyed, glazed, cut and fired. The bisque is a very porous substance that would allow a staining type liquid, (i.e. wine or coffee), to permeate the bisque and discolor the tile if the glaze was compromised or if the liquid was allowed to seep through the grout. Porcelain tiles are made form a porcelain bisque which is very strong and not porous. This non-porosity does not allow a porcelain tile to bond naturally with "Thin set". It requires the addition of a bonding agent, typically liquid latex. This will usually increase the overall cost of installation, depending on the amount of square footage to be installed.
Manufactured tiles are put through several tests that help determine durability, water absorption and slip resistance. A tile's durability is measured on a scale from 1 to 5. A "P.E.I" 1 rate tile is very soft and easy to chip and scratch while a "P.E.I" 5 rate tile is the most durable tile in production.
