A new patio is a long term investment and provides many years of
service and enjoyment. To help you keep your paving looking at its
best for longer, Bradstone has put together these special
guidelines to answer the questions most commonly asked about care,
cleaning and maintenance.
The following guidelines deal with everything from rust marks,
paint, algae and chewing gum, to naturally occurring phenomena such
as efflorescence. Please note that, although sometimes unsightly,
blemishes or stains are unlikely to affect the performance of the
paving in any way.
For all proprietary cleaning materials suggested on these pages,
please consult your paving stockist to recommend an appropriate
product, and remember: always follow the manufacturer’s
instructions. Always test a small area before cleaning the
patio.
Stains
ALGAE AND FUNGAL GROWTHS – Apply a proprietary fungicide
according to the manufacturer’s instructions.
BEVERAGE STAINS – Scrub the stain with hot soapy water. For
stubborn stains apply a 1 : 10 diluted sodium hypochlorite solution
(household bleach solution) and finally rinse thoroughly with clean
water.
CHEWING GUM - Chewing gum is best removed with a suitable
aerosol freezing agent before scraping it off. Use according to the
manufacturer’s instructions.
FRESH OIL STAINS – Soak the oil up with an absorbent cloth or
paper towels. Do not wipe. Then cover the affected area with a
'dry' absorbent powder and leave for 24 hours. Repeat until the
powder has absorbed all or as much of the oil as possible. If a
stain persists, apply a proprietary cleaner according to the
manufacturer’s instructions.
PAINT / WOODSTAIN / VARNISH – Wet Stain - soak up the spillage
with an absorbent cloth or paper towels. Do not wipe. For paint –
the stained area should be immediately scrubbed with scouring
powder and water. For woodstain/varnish – the stained area should
be immediately scrubbed with detergent and water. Paint removers or
solvents should not be used on stains that are less than a week
old, as this will increase penetration into the concrete. Dried
Stain - scrape off as far as possible. Apply an appropriate
proprietary paint remover, preferably one supplied as a thick gel.
Follow the manufacturer’s instructions or contact the paint
manufacturer.
RUST – Rust can be a blemish found on concrete paving and is
caused by iron oxide staining. Use a proprietary rust remover or
concrete cleaner, following the manufacturer’s instructions.
WOOD PRESERVERS / CREOSOTE – Soak the stain with white spirit
and scrub with a hot detergent and water. Finally rinse thoroughly
with clean water, or contact the manufacturer of the preserver.
Efflorescence
Occasionally, after a few weeks or months, white patches may
start to appear on the surface of your paving stones. This is known
as efflorescence (or white bloom).
WHAT IS EFFLORESCENCE? – Efflorescence is a natural phenomenon
and can occur with all cement based products, as well as other
paving products. It may appear randomly and will possibly appear
more pronounced on coloured paving. The white bloom may give the
impression that the colour of the paving is fading but, when wet,
you will find that the efflorescence vanishes and the paving
returns to its original shade. The white bloom will often return
again when the paving dries. Be reassured that efflorescence has no
detrimental effect on the performance of the paving and will
generally disappear with time.
HOW DOES EFFLORESCENCE OCCUR? – All concrete products contain
cement which produces water soluble calcium oxide (lime). Concrete
paving stones contain millions of tiny invisible pores; when
moisture penetrates into these pores - either from rain, dew or
condensation - it dissolves part of the lime to make calcium
hydroxide. When the paving dries out, the calcium hydroxide rises
to the surface and reacts with the carbon dioxide in the air,
sometimes leaving a white bloom of calcium carbonate once the water
has evaporated.
WILL EFFLORESCENCE DISAPPEAR NATURALLY? – Yes. The efflorescence
action is arrested by carbon dioxide reacting with calcium oxide
within the pores of the concrete, so blocking them. The
efflorescence itself is then, over a period of time, either
converted back to soluble salts and washed away by rain or simply
disappears through the action of trafficking, snow or ice. Once the
efflorescence has disappeared naturally it does not usually recur.
It is therefore not necessary to replace the paving or to take
other measures against efflorescence.
HOW LONG WILL EFFLORESCENCE LAST? – This is difficult to predict
as factors such as climate conditions, location and aspect
(damp/shady or open/sunny) are variables which can affect the
extent of the phenomenon. However, on average, it can take from 12
months to two years to disappear.
CAN EFFLORESCENCE BE REMOVED WITHOUT THE WAIT? –
Efflorescence may be removed with a proprietary brand patio
cleaner, but be sure to follow all the manufacturer’s instructions
as incorrect cleaning can result in damage and discolouration of
the paving surface. Efflorescence may reappear if there is free
lime within the paving or the pores have not yet been blocked.
Ideally, the new paving should be left several months to allow as
much of the lime as possible to leave the concrete to minimise the
risk of recurrence.