There is always a remote possibility of an individual fractured tile, usually caused by not being bonded properly and then being impacted by an object dropping o n it. That type of fracture is repaired by replacing the damaged tile. A sure rule of thumb to determining the problem: if the crack goes from one tile to another on a continuous line through the grout joint, the problem, without any doubt, is in the substrate; usually a crack in the slab. The damaged tile would have to be removed, a crack isolation membrane put down and the tile reinstalled; which should solve the problem.
First, with any abrasive tile, you cannot use a standard mop as it will be torn to shreds and leave strings on the floor. A nylon mop will not normally leave "strings" behind. MOST IMPORTANT: Make sure you always use clean water. Change as often as necessary. When cleaning this floor, it must be scrubbed daily (at least) with a brush and, if available, use a vac system (wet vacuum) to pull up the residue of water. At least once a week the floor should be cleaned with an electric floor scrubber. If no vac system is available, surplus water must be accumulated in one area and gathered up, or some commercial kitchens have drains for disposal of excess water.
Because of the course nature of unglazed pavers and unglazed quarry, additional precautions and a more exacting cleaning procedure is required, particularly when using dark grout such as black. If the grout is epoxy, this accentuates the necessity of the above referenced procedure.
If the tile has yet to be grouted, it is recommended that a penetrating sealer be used, which will not change the look of the tile, but fill the small minute holes in the surface that trap the dark grout. This will assist in the clean up procedure. A basic point with all grouting procedures is not to grout a larger area than you can comfortably clean up prior to moving to the next section. (If you have helpers, do not get too far ahead of them.)
If you are concerned about cleaning the black stain from an existing job that was not presealed, it will be with difficulty and you will probably not be able to remove it 100%. Although 90% should be cleanable with a heavy duty stripper such as Aqua Mix's "Sealer and Adhesive Remover." It will necessitate a stiff bristle scrub brush and/or nylon scouring pad and even steel wool can be utilized on more stubborn stains. You will, however, have minute black specs all over the surface where the grout, particularly epoxy, has entered these small holes and cannot be removed.
Epoxy grout film does not respond to the acid cleaning methods used to remove regular cement grout film. It's resistance to cleaning depends on whether it has had time to reach full cure and on whether it is a pure epoxy film or a weak, water-contaminated residue. Therefore, it is best to attempt removal of epoxy film during the first day or two after grouting. The sooner it is done, the easier it will be.
Three options for removing epoxy grout film from tile:
1. Household cleaner and scrub vigorously with a stiff scrubbing brush or power floor scrubber. Rinse thoroughly. Repeat as necessary.
2. Dampen a cloth with lacquer thinner from a paint or hardware store and apply to epoxy film. Promptly use a disposable cloth pad to remove softened film completely from tile surface. Repeat until all traces of film are gone.
3. If there are thick globs or layers of epoxy, to the point you cannot see the tile surface, use a 'heat gun' just long enough to soften this epoxy coating. Scrape or rub off until film is gone
Stone is made shiny by working the surface until it is smooth enough to reflect light. When the surface has been roughed up to the point that light does not reflect evenly, the marble looks dull and needs to be refinished.
The first point is to determine the depth of the scratches. Deep scratches are not only visible, but can be felt with the fingernail. Light scratches can been seen, but not felt. If they are only slight, they can be buffed with a standard floor machine and a red pad. Deep scratches are removed by grinding/sanding the surface down until the scratches no longer show. The surface is then refinished with Multi-Seal Refinisher to bring the shine back.
Once a floor is restored to it's original condition, a maintenance program should be set up and there are a number of companies that provide the components and instructional guidelines. We recommend Aqua Mix and Multi-Seal. There are major maintenance manuals available from both sources.
Unglazed ceramic tile is strongly recommended for most exterior horizontal (floor) applications, interior applications subject to standing water such as shower floors, for very high traffic floors such as airports, train stations, etc. Impervious porcelain tiles are recommended in all 'freeze/thaw' horizontal exterior applications, and even in vertical 'freeze/thaw' applications subject to standing (or in) water.
Although a great variety of glazed tiles are used for counter tops, manufacturers specifically recommend only specific tiles. These are usually double glazed like American Olean's "Crystaltex" or glazes fired at higher temperatures, such as glazes on vitreous and porcelain bodies. High-gloss glazes are not recommended because they will scratch under normal kitchen counter top use. Many owners will select these 'high-gloss' tiles for counter tops even though they are told "they will scratch," because they like the look and do not intend to use their kitchen on a regular basis. American Olean includes specific references in our catalog for each product. Refer to American Olean's Product Catalog.
Vanity Tops: Most tiles are all right to use, except the softest glazes, because of less abuse.
A. It means that the manufacturer guarantees that box of tile meets and exceeds all the requirements as dictated in ANSI 137.1.
B. A 'Master Grade Certificate' can be obtained from the tile manufacturer or supplier upon request. If you want a certificate when picking up your order, request it in advance. This certificate must be signed by both the manufacturer and the installer.