are the various types of concrete pavements?
Concrete pavements can
be constructed of Coloured Slab, Imprinted or Stamped
Concrete or exposed aggregate. These concrete types
may be poured natural or coloured. Colouring may be
added throughout the concrete or trowelled into the
surface only. The strength of the concrete can be
increased by reinforcing it with fiber mesh strands,
steel bars or wire cage. The tensile strength of concrete
pavements range for residential application from 2000
to 10000 psi. The stronger the concrete, the longer
it will last.
Another form of concrete paving is
segmental pavers (also known as paving stones or interlocking
stones). Segmental pavers are commonly used in residential and
commercial paving due to their strength, beauty, resistance to
the elements, unlimited designs, ease of application and the
exceptional ability to lift and relay if the sub-terrain settles
or sinks. Segmental pavers are extremely strong and durable and
are more user friendly than pored concrete for homeowner
Why should I clean and seal my
When concrete is
first installed, it's smooth surface and vibrant colours (when
pigmented) look beautiful. If new concrete surfaces are left
unprotected or improperly protected with inferior products, the
smooth surfaces and vibrant colours will soon deteriorate and stains
will penetrate leaving an unsightly mess. Assumptions that concrete
is strong and maintenance free for life could not be further from
the truth. Concrete is like a sponge, how quickly it deteriorates
depends on what it absorbs. To confirm this, drive through your
neighborhood and look at the countless number of unprotected
concrete and paving stone driveways that are stained and damaged by
natural elements and through owner neglect.
The appearance and/or integrity of
concrete can be effected by the following:
- Staining caused by the
absorption of engine oils, transmission and brake fluids,
automotive and barbecue grease, rust, paint, rubber, red
wines or colas, tree berries and bird droppings. Stains are
aesthetically unattractive and may be difficult to remove
unless the concrete pavement is properly protected.
- Acid Rain will continually
dissolve the concrete's color pigments and erode the smooth
finish of the pavement until it is left dull and
- UV rays & Chlorine based
Swimming Pool Chemicals will attack the iron oxide colour
pigments within the concrete, thus fading it's vibrancy over
- Freeze-Thaw Cycles (caused by
water absorption into the concrete pores from rain or
melting snow on Fall and Winter days where the temperature
is above 0 degrees Celsius. Nighttime temperatures drop
below 0 degrees Celsius and cause this absorbed water to
freeze and expand, breaking down the concrete cells and it's
overall integrity. Over time this will cause erosion,
shaling and spalling. For great examples of this, examine
any new sidewalk compared to a much older sidewalk. The
difference is shockingly obvious.
- De-Icing Salts can pit the
concrete's smooth surface within one winter's use if left
unprotected. A good protective sealer can help resist salt
but will not eliminate the possibility of salt damage to
- Efflorescence Deposits (white
soluble salts which create a whitish haze on concrete
surfaces). Efflorescence will obscure the true color of your
pavement, slow down moisture evaporation and trap dirt in
surface pores. Efflorescence is present in most concrete and
"must" be removed from the surface prior to sealing.
- Weeds and other vegetation will
grow in-between the paving sand joints as seedlings take
root in the surface of the dirty low sand joints.
- Sand loss from the paving
joints is inevitable with wind, rain wash out and tire
pick-up. This may lead to unstable paving stones, possible
base erosion and will promote weed growth. Sand joint
stabilization is imperative and can be achieved through
proper cleaning and sealing techniques.
long should I wait before protecting my concrete pavement?
Poured concrete requires 30
days to cure prior to cleaning and sealing. The slower concrete
dries while retaining moisture, the harder and stronger it becomes.
To achieve this, many concrete installation company's cover their
wet pours with plastic to retain as much moisture for as long as
possible. Some contractors pour their concrete and then within a
short period of time, apply a sprayed curing membrane. A proper
curing membrane should be water friendly, light solids acrylic that
is designed to slow the evaporation process from the concrete. This
light membrane should then be removed 30 days later when the
concrete is fully cured. Proper cleaning and sealing should take
place after the removal of the curing membrane. All concrete
(segmental pavers and poured concrete) require a minimum of 30 to 60
days with constant watering by the owner, to allow efflorescence to
rise to the surface for proper removal prior to the sealing
application. The longer you can wait for efflorescence to rise prior
to cleaning and sealing procedures the better the job will be. The
draw back to waiting too long is damage from staining, tire marks,
colour fading from UV light and acid rain, dirt and most importantly
freeze-thaw cycle damage.
concrete require chemical cleaning even if it's new?
All concrete and
paving stones have efflorescence. Paving stones also have clay, dirt
and silt in their surface pores due to the sweeping of sand into the
paving joints during the final stage of the installation. These
contaminants obscure the concrete's true colours and the ability of
the sealer to properly bond with the surface. Proper chemical
cleaning eliminates all of these hazards and ensures a beautiful,
long lasting protective coating that will facilitate easy
maintenance. Chemical cleaning is also necessary prior to every
re-sealing so that dirt and contaminates are not trapped between the
layers of sealer. Sealing or re-sealing without the proper chemical
cleaning application will eventually require that all the sealer be
chemically or mechanically stripped away at exorbitant costs ($2.00
and up per square foot).
is efflorescence and how can it be cleaned from concrete
Efflorescence is a
whitish powder like deposit which often appears on concrete and clay
products. This deposit is a residue of a soluble salt carried to the
surface of the pavement or wall by evaporating moisture, which
leaves a dry powder or calcified deposit upon drying. A phenomenon
reported as early as the 1870's, efflorescence in itself, does not
affect the structural integrity of the substrate. Efflorescence
usually rises after installation as a powdery substance but can also
form harder patches of calcium carbonate during the manufacturing
process. The later being more difficult to remove. Hard, definitive
white lines or patches (some appear to have a slight bluish tinge)
on paving stones must not be confused with efflorescence. These
residues are "lime" and often can not be removed at all or at least
without substantial damage to the substrate. These pavers should be
changed for aesthetic purposes.
The origin of these salts are found
in the native soil, gravel or limestone pavement base, in the
sand, aggregate, ash or cement used to manufacture concrete
brick block or paving stones. Salts dissolve in either the
ground water, rain water or water added to the mix the concrete
and moves to the surface through evaporation. In basement walls,
this travel action has been measured to be as much as 600 mm.
Since the sun and warmer exterior air evaporates moisture at a
faster rate, it causes a "wicking" action that continues to draw
moisture to the exterior surface until the substrate is dry. The
efflorescence continues to surface until either the salt or
moisture supply has been exhausted - which in most salt cases
occurs within 60 days - but has been known to last for many
years in extreme cases.
Most efflorescence can only be
removed with acidic solutions (such as acid rain over extended
periods of time, or acidic based efflorescence cleaners).
Although most efflorescence will dissipate with a few years of
acid rainfall, Stonesaver does not recommend waiting for this to
occur before applying a protective sealer. During this extended
waiting period, the Pavement or walls could be damaged by
staining, acidic etching, freeze-thaw cycles, pitting, spalling,
traffic wear and color fading. Stonesaver recommends a minimum
60 day waiting period (with constant watering by the homeowner)
after wall or pavement installation, to allow for the majority
of efflorescence to surface, prior to cleaning and sealing
CLEANER & SURFACE PREP
Surface Prep is a highly concentrated Efflorescence Cleaner
which requires no handling or pre-mixing of chemicals. Surface
Prep comes complete with a pre-attached "E-Z Sprayer" (a hose
end adapter which connects to your garden hose and disperses the
Surface Prep in a cherry scented soapy solution. After a light
scrubbing, the E-Z Sprayer adapter (along with an additional
hose and gun) can be used to facilitate rinsing the cleaner from
the surface. A one litre bottle of Surface Prep including E-Z
Sprayer adapter, weighs less than 3.5 pounds and easily cleans
300 to 500 square feet of concrete pavement. It is the most user
friendly acidic based cleaner available anywhere! Once the
surface is completely dry, Stonesaver's Premium Sealers, Water
Repellents or Paints can be applied for surface beautification
and long term protection. Never: seal or re-seal a concrete
surface which has not been previously cleaned with Stonesaver's
Stain & Surface Prep Cleaners.
|Can I walk
or drive on my concrete during the cleaning and sealing
Once the surface is properly
cleaned, it should not be contaminated prior to sealing. Vehicle
tire tracks, grass stains from lawn mowers, skid marks from bicycles
or mud from dirty shoes will be trapped and visible for years if
sealed over. Between the cleaning and sealing process, pedestrians
may walk on the surface with clean, dry shoes only.
|Other important rules to follow in-between
the cleaning and sealing process?
Once the surface has been
cleaned it needs to thoroughly dry prior to sealing. This can take
24 hours in the heat of mid summer to seven or more days in the
Spring or Fall. Areas that are covered like carports or areas that
are shaded from trees will take much longer to dry at any time of
year. Sealing a surface with excess moisture content will cause
moisture blushing and possible sealer de-lamination over time. Never
seal until you are sure that the surface is "completely" dry.
A good rule of thumb for paving
stones is " when the sand joints are powdery dry and do not
clump up when you run a finishing nail through the sand, then
the entire surface should be ready to seal. For concrete, "if
the cut lines show dampness or produce moisture when blown with
a leaf blower, the surface is not ready to seal".
Remember! Turn off your irrigation
system (sprinklers) throughout the cleaning and sealing process
and for 24 hours during the drying process of the
better to roll or spray the sealer?
based sealers are designed to be applied in a fully saturating
method either by rolling or spraying with an airless high volume
sprayer. When using a roller, use a high pile 30 mm nap roller with
a plastic sleeve and solvent resistant paint tray. Ensure that the
concrete or pavers are sealed to the point of full saturation with
any excess sealer being back rolled off the surface if unabsorbed
within 1 minute.
If you wish to spray, choose only
solvent resistant, high volume, airless sprayers. The use of
pump sprayers is not advisable for many reasons. First, all pump
sprayers are air driven and can inject air bubbles into the
sealer. Pump sprayers also deliver variable rates of sealer
depending on the air pressure that is in the container at that
moment. As the air pressure constantly drops within the
container between hand pumping, the flow rate of sealer also
drops proportionately and causes uneven application. Most pump
sprayers have such low flow rates that they can not deliver
enough sealer to properly saturate the surface pores. Lastly,
most pump sprayers are equipped with rubber gaskets that are not
compatible with Stonesaver solvent based sealers. Most solvent
based sealers require sprayers that are equipped with Viton or
Teflon gaskets. Rubber gaskets will dissolve quickly when
submersed in solvents and will interfere with the operation of
How often do I need to seal my
are the longest lasting protective products on the
market. Our economical blend Contractor's
Choice Sealer will protect for up to 2 years on
any concrete surface. The Concrete
Sealer for Coloured Slab, Imprinted or Stamped
concrete will protect for 2 to 3 years. The Paving
Stone Sealer will protect for 3 to 4 years. The
Floor Protector paints can protect for many years
depending on wear and abuse. The Porch & Floor
urethane coatings can protect for many years depending
on wear and abuse. The Concrete
Water Repellent will protect for up to 10 years
on vertical above grade concrete surfaces.
What do I do if staining occurs or
contaminants land on my concrete pavement?
Certain stains or
contaminants like paint, most acids, chewing gum, tar, rubber, rust,
berries and tree sap are all topical stains. They do not penetrate
the sealer and are very easy to remove by applying the correct stain
cleaner, scrubbing and rinsing. Usually only one cleaning is
necessary for these types of stains.
Stains like oil, brake fluid,
transmission fluid, anti-freeze , gasoline and silicone ( Armor
All) are all penetrating stains. Since Stonesaver protective
sealers must be designed as breathable sealers, these aggressive
fluids can slowly work their way through the breathable sealer
and into the concrete below. How fast they can penetrate depends
on the aggressiveness of the fluid. As an example, Oil depending
on it's viscosity and the age of the protective sealer may take
days to weeks to work it's way through, while gasoline,
transmission or brake fluid will penetrate within hours. For
these types of penetrating stains, you must first remove the
sealer over the stain with Stonesaver Stripper.
Failure to do this will result in exhausting cleaning attempts
with negative results, as the stain is trapped under the sealer.
After stripping the sealer away, you would use the appropriate
stain remover to extract the fluid from the exposed concrete.
You must then wait until fully dry and seal with a brush, using
the appropriate Stonesaver sealer.
The best advise for staining is to
always keep some Stonesaver Citrus
Oil Degreaser on hand and to immediately clean
penetrating stains immediately as you notice them. If you don't
keep stain cleaners on hand, then when you notice a stain and
have to get around to buying some cleaner, it might be too late
to remove easily and inexpensively.
does it mean if my sealer or concrete has hazy white spots and how do I
Sealed concrete can have
whitish areas for the following reasons:
If the concrete was
not properly cleaned and prepared for sealing, then the sealer
can fail to bond to the concrete and may eventually start to
lift and peel away. This will cause a white hazy appearance
until the sealer has been completely de-laminated.
Allow sufficient time for the sealer to wear
completely away or remove mechanically by stripping or soda
blasting, prior to a proper cleaning and sealing application.
If the concrete has
been sealed too often (example; every year) then excess sealer
build up will eliminate breathability and cause vapor entrapment
in the sealer and a foggy appearance.
sufficient time for the sealer to wear completely away or remove
mechanically by stripping or soda blasting, prior to a proper
cleaning and sealing application.
If a solvent based
sealer has been applied to a damp surface or if the surface gets
wet while the sealer is curing, then the sealer will moisture
blush (usually within 48 hours after sealing). Moisture blushed
sealer appears white as the acrylics are crystallized due to the
interrupted drying process.
mixture of toluene solvent and sealer at a ratio of 2 to 1 and
apply over the clean dried moisture blushed sealer and work in
with a roller. Allow to dry without moisture intrusion.
salts are present underneath the protective sealer they will
exhibit white dull areas.
is no correction for this and efflorescence is part of all
concrete and can not be controlled.