Natural
Stones
Care and Maintenance
Limestone
and slate look beautiful and are very durable when properly protected and maintained. Limestone (including travertine and marble) is
more porous than slate and some other stone and, due to this high porosity, it is more
susceptible to the absorption of water, oils, grease and dirt. With proper initial installation and sealing, and
an ongoing care and maintenance programme, the natural beauty of all stone will endure for
generations.
All
sealing and maintenance products should be initially tested on an inconspicuous area of
the installation to assure suitability with the stone, grout, etc. In all cases, follow the manufacturer’s
recommendations for the specific product.
Limestone, being porous, can absorb stains from many items
including the dye in grouts. To ensure the
best possible installation, a first coat of sealer should be applied as a grout release
prior to grouting. This will resist grout dye
absorption, facilitate grout residue removal (up to 45% faster) and offer stain resistance
during the construction process. Depending
upon the porosity of the material,
511 Porous Plus or
511 Impregnator are the recommended sealers.
The appropriate sealer for most of the denser slates and quartzites is the 511 Impregnator. Follow the sealer manufacturer’s instructions
for the proper application procedure.
After grouting, apply a second coat of sealer and allow it to
cure. This will complete the sealing of the
stone and provide water and stain protection for the grout joint. For very porous stone, a third application may be
recommended.
If you are trying to retain the natural look of the stone, we
recommend stopping at this point and putting the area into service. This type of finish will require the least amount
of maintenance and is recommended for high traffic and food areas for maximum stain and
slip resistance.
For sawcut, flamed, tumbled or textured limestones and slates, a
colour enhancer may be used. When used in
conjunction with Porous Plus or 511 Impregnator,
Mira Matte colour enhancer seals and protects
while leaving a beautiful, low maintenance, colour enhanced finish. Follow the instructions above for the sealing of
the stone and grout. Once dry, apply a coat
of the colour enhance as per the instructions. While
the enhancer is still slightly wet, buff the surface to remove streaks and application
marks. A second application may be carried
out if a deeper colour is desired.
Stone must be dry and free of contaminants, including previously
applied sealers, dirt and grout residue before proceeding with the sealing process. Remove all existing solvent-based floor coatings
and/or waxes with a floor stripper to return the stone to its natural finish. Proceed with the sealing as per a new
installation.
For heavy duty cleaning (hard water deposits, grout residue,
efflorescence, rust and other heavy-duty dirt and grime) use an acid based grout and film
remover. Since limestone reacts with acids
and surface etching may occur, a small test area must be done to ensure that the desired
effect is obtained. The manufacturer’s
recommendations should be strictly followed.
For cleaning of stains, Liquid
Poultice is a biodegradable, non-acidic, deep cleaner designed to penetrate deep into
the pores of the stone to safely lift out mold, mildew, algae, fungus, coffee, tea and
other types of foreign matter. For specific
stain removal troubleshooting, refer to the Stone
Tile Stain Removal Guide for further information.
Although
this type of stone surface will not show wear as readily as other materials, it should be
kept as clean as possible. Any grit on the
surface will tend to scratch and break down the surface pores of the stone faster and
hence cause the installation to require more frequent resealing. Whenever possible, light sweeping or vacuuming
should be undertaken rather than wet mopping since mopping will tend to leave a residue on
the surface.
When sweeping will not clean the surface then light damp mopping will be required. Light cleaning should be carried out using a mild, non-oil based, neutral pH detergent (we recommend Mira Clean #1) and a clean mop. Rinse the mop frequently. Rinse the area with clean water and a thoroughly wrung-out mop after cleaning to eliminate any streaks or residue buildup on the surface. If mop marks or water spots are left on the surface, these may be buffed out using a dry, clean, white floor pad on a floor machine. This pad should only be used for the stone floor areas and only buff those areas affected. Mira Soap can also be used as an alternative for ongoing maintenance. It will clean and protect in one step while adding a slight patina to the finish. No rinsing is required with Mira Soap and it can be used as often as necessary.
In addition, any acid-based foreign material (wine, orange juice, etc.), if allowed to sit on limestone for a prolonged period, may slightly etch the surface. This will be less noticeable on honed, sawcut or textured materials than on polished and can be repaired using a fine grit of emery paper and water to bring back the original lustre. Ensure that the area is then resealed.
If
colour enhancement is desired, a light cleaning can be done as needed by using Mira Clean with Mira Matte colour enhancer added to the water. For heavily worn and/or soiled areas remove old Mira Matte with a stripper (Mira Strip) before reapplying.
Depending
upon the amount and type of use (residential, commercial, etc.) and the frequency and type
of maintenance carried out, all stone surfaces must be resealed periodically. Most commercial installations should be resealed
every 1 to 3 years and lighter or residential uses every 3 to 5 years. One indicator that resealing is required is if the
installation begins to absorb water or stains. Strip
off all existing surface sealers or enhancers, clean any specific stain areas and reseal
as per a new installation.
Occasionally a stone may require
repair or replacement due to site conditions, installation problems or a hidden fault in
the stone. Removal and replacement can be
carried out with particular care being taken to match the existing grout and to thoroughly
seal the repair after installation.
Some crosscut travertines,
because of the nature of the stone, have small internal voids that are not visible on the
surface of the stone. It is possible that, if
a particular point load is placed on the spot, that the stone surface can break into the
void. This is not a problem on unfilled
travertines. For filled travertine
installations, a periodic inspection can be carried out and visible voids can be easily
filled on-site. For light traffic uses, a
regular unsanded (or sanded for larger voids) grout (colour to match the lighter veining
of the stone) mixed with latex additive can be applied with a spatula. A second application may be required if the grout
shrinks excessively. Ensure all grout haze is
removed and seal the repair. For any high
traffic, commercial repair, an epoxy grout should be used.