Maintenance & Care

Sealing of Natural Stone Paving

Sealing of Natural Stone Paving

Natural stone pavers do not specifically require sealing and will be left unsealed on the majority of projects. Natural stone pavers are porous to a degree and sealing may be considered an option in some cases. Sealing is also considered for its effect on appearance i.e. the wet look.

There are two general categories of sealers – penetrating and coating sealers.

I.

Penetrating sealers

Penetrating sealers are designed to be absorbed into the surface of the paver. They usually do not leave a noticeable  sheen on the surface of the paver after they have been applied although some types of penetrating sealers particularly oil based (solvent) sealers may make the surface seem darker in appearance. They are below surface fillers whose primary function is to reduce the absorbency of the paver surface and the capillary action in the stone. They also do not significantly affect the slip resistance of the pavers and do not need reapplication often nor do they show wear.

Typically the application of 2 coats of a good quality “penetrating” sealer is advised.

II.

Coating sealers

Coating sealers or epoxy-based sealers are designed to remain on the surface of the paver and grout joint and generally leave a sheen or gloss that is commonly referred to as the “wet look”. These sealers typically alter the look; slip resistance and colour of natural stone.

Coating sealers are a surface coating whose primary function is to reduce absorbency of the paver surface. Many  coating sealers require reapplication regularly, especially in high traffic areas or where exposed to UV. Slip resistance can be affected by surface coatings and due care should be given to this as obviously the co-efficient of friction test results are not applicable to sealed product unless units are tested with the coating sealer

Note Sealing should never be considered as a means of stopping or deterring efflorescence. Efflorescence will migrate to the surface of the paver by capillary action and be trapped below the surface of the sealer accentuating the problem.

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Maintenance & Care

Anti-slip Treatments

These are mentioned here because they tend to have an adverse effect on the cleaning of pavers and tiles. Older style treatments are based on fluorides, which are just safe enough to be used and just strong enough to attack the surface of the paver or tile.

Most of these treatments work by etching the surface (putting a fine pinhole effect in a previously glassy finish) which produces a slight increase in slip resistance. The major effect is dirt can become entrapped in these tiny voids leaving the paver looking grubby.

New anti-slip treatments tend to be epoxy based.

The emergence of Anti-slip treatments on the market can be attributed to concerns about safety and public liability.

Pavers are generally specified with the appropriate texture and finish to comply with the Australian Standard for slip resistance for the given application and any treatment to be applied is at the discretion of the customer. The customer should consult the manufacturer of the anti-slip treatment for further information.

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Maintenance & Care

Cleaning & Maintenance

Due to the hardness of granite and the surfaces resistance to soiling, generally little maintenance is required. A cleaning regimen is suggested to remove build-up of dirt and to maintain the appearance of the paver/stone.

Like all stonework, granite is generally best cleaned using warm water and a mild detergent on a regular basis in ensure aesthetics and product longevity.

Stone can be sealed at the outset, to help prevent immediate dirt ingress and facilitate future cleaning.  Granite is no different. As durable as it is, granite is not ‘self-cleaning’.

Once sealed correctly, granite requires minimal ongoing maintenance, other than a good cleaning as per cleaning and maintenance schedule.

The service of a competent pressure cleaning and sealing company familiar and experienced with cleaning and  maintaining natural stone is always an advantage. Take care not to remove grout or joint filling material.

Allowing any soiling on the stone surface to be baked on in direct sunlight for weeks at a time, makes stain removal more difficult.

The cleaning frequency and methodology will vary depending on surface finish, volume of traffic, dirt accumulation and appearance requirements, and is therefore best trialed and set to suit the particular situation.

For large areas, it is advisable to use a commercial floor scrubber or ride-on cleaning machine. Where ride on cleaning machines are employed, these are generally more effective, when used in conjunction with heavy duty detergent hot water application.  A high traffic pedestrian mall would typically be scrubbed and washed down approx. every 3-4 weeks by a ride-on machine.

Spot cleaning can be done when needed, using neat detergent, bleach, or in extreme circumstances,  diluted (30:1) hydrochloric acid.

Note Paving should be thoroughly wet down before any acid is applied
Note If unsure of the stone and its reaction to acid -test a small area prior to commencement of work to check that  the particular stone will not be adversely affected by acid.

Maintenance Note:

  • • Clean as necessary

• Re-exfoliate on site when required to maintain slip resistance (in extreme cases)
• Replace broken pavers
• Reinstate paving after works that require footpath surface to be opened
• Use matching stones for replacement

Periodic Maintenance

Problem Description Solution
Efflorescence A white or yellow deposit of salts
which may occur after rain. It can
come from the paver or the soils under
the paving.
Can be removed by placing coarse &
salt free sand on surface, stiff brushing.
Moulds This is a common problem usually
found in damp and shady places.
Vigorous brushing when dry will
emove this. There are many products
in the market for this purpose, use
accordingly to manufacturers
specifications
Food stains and tyre marks It is recommended that any spills
be treated immediately. The use of a
neutral cleaner and scrubbing should
have the desired effect.There are many
products in the market for this purpose,
use accordingly to manufacturers
specifications
Dirt and grime This may be cleaned by frequent
sweeping and occasional hosing
of surface.

Exfoliated or Sawn Finished Granite

External granite paving should be cleaned on a regular basis either fortnightly or monthly clean using high pressured water. Take care not to remove grout or joint filling material when using high pressure water.

External granite paving can benefit from a mild acid wash on an as-needs basis to remove any dirt build up by using a diluted hydrochloric acid mix: 1 part hydrochloride acid to 30 parts water applied using a stiff bristled broom. Wash off within a couple of minutes with a further rinse 10-15 minutes later. Take care when using hydrochloric acid, use safe work practices and provide appropriate ventilation and avoid damage to glass or other fittings from acid and avoid use where polyurethane/silicone jointing exist.  Acid washing treatments should be professionally applied.

For internal exfoliated granite paving, wash with mild detergent followed by clean water. Mop down surface once or twice per week with regular vacuuming.

• Rough finishes will not repel contaminates such as coffee or wine like a polished finish will and can result in the surface absorbing the substance leaving a stain.
• In an outdoor environment, pressure spraying with detergent is suggested to remove stains.
• In an interior environment, generally the only solution is hand washing with detergent.
• For stubborn stains, cleaning using a poultice or complete replacement (of unit or units) may be the only  practical solution.
• NB! At all times test the cleaning method in a remote area first.

Polished Granite

A wash with mild detergent followed by clean water will suffice in foyers and lift lobby areas. For internal polished and honed granite paving, mop down surfaces daily with a suitable detergent which doesn’t require excessive rinsing off to stop build up and yellowing.

• Don’t use abrasive cleaning products such as scouring pads as they may scratch the surface if used vigorously
• Avoid using silicone based cleaning pads as they may leave a coating making the surface impermeable for  further cleaning.
• NB! At all times test the cleaning method in a remote area first

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Maintenance & Care

Cleaning & Maintenance Chart

Granite
Cleaning & Maintenance Chart

Due to the hardness of granite, little maintenance is generally required.
Product or Application Finish Comments Internal or
External
General Cleaning
product Advice
Method &
Precautions
Cleaning Frequency*
*Frequency of cleaning
is required to be
assessed on a case
by case basis.
Polished
& Honed
Granite
These finishes tend to repel
contaminates, such as coffee or
soft drinks better than exfoliated
or sawn finishes
Internal Neutral pH detergent –
For indoors the typical
solution is hand washing
with detergent. For large
areas, it is advisable to
use neutral pH detergent
with a commercial
floor scrubber
Mop down with a
neutral pH detergent
which doesn’t require
excessive rinsing off to
stop build up and yellowing.
Mop – daily
Exfoliated These finishes will not repel
contaminates, such as cof-
fee or soft drinks, as well as a
polished finish. Instead, it will
absorb then leave a stain.
Internal Neutral pH detergent –
For indoors the typical
solution is hand washing
with detergent. For large
areas, it is advisable to
use neutral pH detergent
with a commercial
floor scrubber
Mop once or twice
Mop once or twice
nights the surface
should be vacuumed of
dust using a soft pliable
brush fitting to ensure
material is picked up
from the even surface.
Mop – once or twice per week
Neutral pH detergent – Clean with water with a neutral pH detergent High Pressure spraying with detergent is suggested to remove the stains in an outdoor setting High water pressure clean – fortnightly / monthly
It should be noted that a water blaster/high pressure device may be used directly, but care is to be taken not to remove grouted joints.
For large areas, it is advisable to use neutral pH detergent with a commercial floor scrubber/ride-on Commercial Scrubber – fortnightly / monthly
For larger areas (such as a high traffic pedestrian mall), it is advisable to use heavy duty neutral pH detergent and hot water with a commercial floor scrubber / ride-on cleaning machine Commercial Scrubber / Ride-on cleaning machine – every 3 to 4 weeks
Pavers Like all textured finishes, it will have the tendency to retain some dirt and spillages until removed. Mild Acid Wash – External paving can benefit from a mild acid wash, as needed, to remove any dirt build up. The mix is usually 1 part Hydrochloride Acid to 30 parts water. This is broomed on using a stiff bristled broom and washed off within 2 minutes with a further rinse 10 minutes later Mild acid-wash – Monthly (or as required)
Exfoliated or Sawn Finished Granite Exfoliated’ finish to granite is specially suited and recommended to floor areas where the ‘slip factor’ is of concern, as this finish well exceeds the set minimum requirements. External Acid wash should be avoided where polyurethane /silicone jointing and exists and precautions need to be taken to avoid the deterioration of grouting material between pavers.
Care should be taken to avoid damage to glass or other fittings from acid as well as proper ventilation and taking necessary safety considerations for use of Hydrochloric acid.
If the surface is
extremely dirty, the
concentration may be
increased 10:1
Hydrochloric acid
Other organic
anti-fungal cleaners
Refer to Manufactures
instructions. At all times
test the cleaning method
in a remote area first.
Proprietary cleaning
agents – To remove
stubborn stains
Refer to Manufactures
instructions. At all times
test the cleaning method
in a remote area first.
Ammoniated cleaner
– For oil and grease
marks,
Scrub with a solution
of clean water and an
ammoniated cleaner
(20:1), and then follow
with a pH neutralizer.
Finish by using a wet
vacuum (for internal) or
simply hose down with
clean water (for
external).
Wash with mild a neutral pH detergent followed by clean water rinse For indoors the
typical solution is hand
washing with detergent.
For larger areas, it is
advisable to use neutral
pH detergent with a
commercial fl oor
scrubber.
Mop – daily
Tiles Polished
& Honed
Granite
Foyers and lift lobbies Internal Don’t use abrasive
cleaning products, steel
wool or silica carbide
scouring pads, as these
will scratch the surface
if used vigorously, avoid
using silicone based
cleaning pads as they
may leave a coating,
making the surface
impermeable for further
cleaning.
Cladding External Granite cladding on
external walls may only
need to be wiped down
when the windows are
cleaned.
Download PDF Granite – Cleaning & Maintenance Chart
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