“Paint
Failure” is
a misnomer. It is almost never
the paint that fails. When a paint
film lets go prematurely, it is
usually caused by one of 3 conditions:
moisture, poor preparation, or
faulty application.
In all cases, the cause of paint failure must be identified and cured before
repainting.
Click
on the type of
problem for details.
ALLIGATORING
Patterned
cracking in the
surface of the
paint film resembling
the regular scales
of an alligator.
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POSSIBLE
CAUSES:
- Application
of an extremely
hard, rigid coating,
like an alkyd
enamel, over
a more flexible
coating, like
a latex primer.
- Application
of a top coat
before the undercoat
is dry. Natural
aging of oil-based
paints as temperatures
fluctuate. The
constant expansion
and contraction
results in a
loss of paint
film elasticity.
- Often
cross grain crazing
means paint build-up
is the culprit.
SOLUTION:
- Old
paint should
be completely
stripped by scraping
and sanding the
surface; a heat
gun or infra-red
heater can be
used to speed
work on large
surfaces, but
take care to
avoid igniting
paint or substrate.
- The
surface should
be primed with
high quality
linseed oil-based
primer, then
painted with
a top quality
exterior latex
paint.
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BLISTERING
Bubbles
resulting from
localized loss
of adhesion, and
lifting of the
paint film from
the underlying
surface.
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POSSIBLE
CAUSES:
- Painting
a warm surface
in direct sunlight.
- Application
of oil-based
or alkyd paint
over a damp or
wet surface.
- Moisture
escaping through
the exterior
walls (less likely
with latex paint
than with oil-based
or alkyd paint).
- Exposure
of latex paint
film to dew,
high humidity
or rain shortly
after paint has
dried, especially
if there was
inadequate surface
preparation.
SOLUTION:
- If
blisters go down
to the substrate:
try to remove
the source of
moisture. Repair
loose caulking;
consider installing
vents or exhaust
fans. Remove
blisters (see
Below).
- If
blisters do not
go all the way
down to the substrate:
remove them by
scraping, then
sanding, prime
bare wood and
repaint with
a quality latex
exterior paint.
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CHALKING
Formation
of fine powder
on the surface
of the paint film
during weathering
which can cause
color fading. Although
some degree of
chalking is a normal,
desirable way for
a paint film to
wear, excessive
film erosion can
result from heavy
chalking.
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POSSIBLE
CAUSES:
- Use
of a low-grade,
highly pigmented
paint.
- Use
of an interior
paint for an
outdoor application.
SOLUTION:
- First,
remove as much
of the chalk
residue as possible,
scrubbing with
a stiff bristle
brush (or wire
brush on masonry)
and then rinse
thoroughly; or
use power washing
equipment. Check
for any remaining
chalk by running
a hand over the
surface after
it dries. If
noticeable chalk
is still present,
apply a quality
oil-based or
acrylic latex
primer (or comparable
sealer for masonry),
then repaint
with a quality
exterior coating;
if little or
no chalk remains
and the old paint
is sound, no
priming is necessary.
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CHALK
RUN-DOWN
The
washing down
of chalk from
an excessively
eroding paint
onto another
area below (a
brick foundation,
for example),
ruining its appearance
(see Chalking).
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POSSIBLE
CAUSES:
- Use
of a lower quality,
highly pigmented
paint.
- Use
of an interior
paint for an
outdoor application.
- Erosion
of factory-finished
metal siding.
SOLUTION:
- Remove
as much of the
chalk residue
as possible (see
Chalking). Scrub
any stained areas
with a stiff
brush, using
a detergent solution;
rinse thoroughly.
In cases of severe
staining, an
acid wash may
be necessary.
Either way, if
the affected
area dries to
a different color,
consider painting
it with a quality
latex paint.
Eroding aluminum
siding should
be thoroughly
cleaned (power
washing recommended)
before painting
with a quality
exterior latex
paint.
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CRACKING
/ FLAKING
The
splitting of a
dry paint film
through at least
one coat, which
will lead to complete
failure of the
paint. Early on,
the problem appears
as hairline cracks;
later, flaking
of paint chips
occurs.
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POSSIBLE
CAUSES:
- Use
of a lower quality
paint that has
inadequate adhesion
and flexibility.
- Overthinning
the paint or
spreading it
too thin.Poor
surface preparation,
especially when
the paint is
applied to bare
wood without
priming.
- Painting
under cool or
windy conditions
that make latex
paint dry too
fast.
SOLUTION:
- It
may be possible
to correct cracking
that does not
go down to the
substrate by
removing the
loose or flaking
paint with a
scraper or wire
brush, sanding
to feather the
edges, priming
any bare spots
and repainting.
- If
the cracking
goes down to
the substrate
remove all of
the paint by
scraping, sanding
and/or use of
a heat gun; then
prime and repaint
with a quality
exterior latex
paint.
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DIRT
PICKUP
Accumulation
of dirt, dust particles
and/or other debris
on the paint film;
may resemble mildew.
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POSSIBLE
CAUSES:
- Use
of a low quality
paint, especially
lower grades
of satin or semigloss.
Soil splashing onto siding.
- Air
pollution, car
exhaust and flying
dust collecting
on house body
and horizontal
trim.
SOLUTION:
- Wash
off all surface
dirt before priming
and painting,
using a scrub
brush and detergent
solution, followed
by a thorough
rinsing with
a garden hose.
Heavier dirt
accumulations
may require the
use of a power
washer. While
dirt pickup can't
be eliminated
entirely, top
quality exterior
latex paints
typically offer
superior dirt
pickup resistance
and washability.
Also, higher
gloss paints
are more resistant
to dirt pickup
than flat paints,
which are more
porous and can
more easily entrap
dirt.
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EFFLORESCENCE
/ MOTTLING
Crusty,
white salt deposits,
leached from mortar
or masonry as water
passes through
it.
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POSSIBLE
CAUSES:
- Failure
to adequately
prepare surface
by removing all
previous efflorescence.
- Excess
moisture escaping
through the exterior
masonry walls
from behind.
SOLUTION:
- If
excess moisture
is the cause,
eliminate the
source by repairing
the roof, cleaning
out gutters and
downspouts, and
sealing any cracks
in the masonry
with a high quality,
water-based all-acrylic
or siliconized
acrylic caulk.
If moist air
is originating
inside the building,
consider installing
vents or exhaust
fans, especially
in kitchen, bathroom
and laundry areas.
Remove the efflorescence
and all other
loose material
with a wire brush,
power brush or
power washer;
then thoroughly
rinse the surface.
Apply a quality
water-based or
solvent-based
masonry sealer
or primer, and
allow it to dry
completely; then
apply a coat
of top quality
exterior house
paint, masonry
paint or elastomeric
wall coating.
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FADING / POOR COLOR RETENTION
Premature
and/or excessive
lightening of the
paint color, which
often occurs on
surfaces with sunny
southern exposure.
Fading/poor color
retention can also
be a result of
chalking of the
coating.
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POSSIBLE
CAUSES:
- Use
of an interior
grade of paint
for an outdoor
application.
- Use
of a lower quality
paint, leading
to rapid degradation
(chalking) of
the paint film.
- Use
of a paint color
that is particularly
vulnerable to
UV radiation
(most notably
certain bright
reds, blues,
and yellows).
- Tinting
a white paint
not intended
for tinting,
or overtinting
a light or medium
paint base.
SOLUTION:
- When
fading/poor color
retention is
a result of chalking,
it is necessary
to remove as
much of the chalk
as possible (see
Chalking). In
repainting, be
sure to use a
quality exterior
house paint in
colors recommended
for exterior
use.
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FROSTING
A
white, salt-like
substance on the
paint surface.
Frosting can occur
on any paint color,
but it is less
noticeable on white
paint or lighter
tints. On masonry,
it can be mistaken
for efflorescence
(see Efflorescence
and Mottling).
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POSSIBLE
CAUSES:
- Forms
mostly in protected
areas (such as
under eaves and
on porch ceilings)
that do not receive
the cleansing
action of rain,
dew and other
moisture.
- Use
of dark-colored
paints that have
been formulated
with calcium
carbonate extender.
Application of a dark-colored paint
over a paint or primer containing calcium
carbonate extender.
SOLUTION:
- Frosting
can be a stubborn
problem. It often
cannot be washed
off readily.
Moreover, the
condition can
recur even as
a bleed-through
when a new top
coat is applied.
In extreme cases,
it can interfere
with adhesion.
The best remedy
is to remove
the frosting
by wirebrushing
masonry or sanding
wood surfaces;
rinse, then apply
an alkyd-based
primer before
adding a coat
of high quality
exterior paint.
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LAPPNG
Appearance
of a denser color
or ligher gloss
where wet and dry
layers overlap
during paint application.
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POSSIBLE
CAUSES:
- Failure
to maintain a "wet
edge" when
applying paint.
SOLUTION:
- Maintain
a wet edge when
painting by applying
paint toward
the unpainted
area and then
back into the
just painted
surface. This
technique (brushing
from "wet
to dry" rather
than vice versa)
will produce
a smooth uniform
appearance. It
is also wise
to minimize the
area being painted,
and plan for
interruptions
at a natural
break, such as
a window, door
or corner (especially
important when
applying stain
to bare wood).
Alkyd paints
generally have
superior wet
edge properties.
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MILDEW
Black,
gray or brown areas
of fungus growth
on the surface
of paint or caulk.
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POSSIBLE
CAUSES:
- Forms
most often on
areas that tend
to be damp, and
receive little
or no direct
sunlight (walls
with a northerly
exposure and
the underside
of eaves are
particularly
vulnerable).
- Use
of a lower quality
paint, which
may have an insufficient
amount of mildewcide.
- Failure
to prime bare
wood before painting.
- Painting
over a substrate
or coating on
which mildew
has not been
removed.
SOLUTION:
- Test
to distinguish
mildew from dirt
by applying a
few drops of
household bleach
to the discolored
area; if it disappears,
it is probably
mildew. Treat
the mildew by
applying a mixture
of water and
bleach, 3:1,
and leave on
for 20 minutes,
applying more
as it dries.
Wear goggles
and rubber gloves.
Then scrub and
rinse the area.
Apply an exterior
latex primer,
then a top-of-
the-line exterior
latex paint in
flat, satin,
semigloss or
gloss finish,
depending on
the desired appearance.
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NAILHEAD RUSTING
Reddish-brown
stains and spots
on the paint surface.
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POSSIBLE
CAUSES:
- Non-galvanized
iron nails have
begun to rust,
causing bleed-through
to the top coat.
- Non-galvanized
iron nails have
not been countersunk
and filled over.
- Galvanized
nailheads have
begun to rust
after sanding
or excessive
weathering.
SOLUTION:
- When
painting new
exterior construction
where non-galvanized
nails have been
used, it is advisable
to first countersink
the nailheads,
then caulk them
with a top quality,
waterbased all-acrylic
or siliconized
acrylic caulk.
Each nailhead
area should be
spot primed,
then painted
with a quality
latex coating.
When repainting
exteriors where
nailhead rusting
has occurred,
wash off rust
stains, sand
the nailheads,
then follow the
same surface
preparation procedures
as for new construction.
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PAINT INCOMPATIBILITY
Loss
of adhesion where
many old coats
of alkyd or oil-based
paint receive a
latex top coat.
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POSSIBLE
CAUSES:
- Use
of water-based
latex paint over
more than three
or four coats
of old alkyd
or oil-based
paint may cause
the old paint
to "lift
off" the
substrate.
SOLUTION:
- Repaint
using another
coat of alkyd
or oil-based
paint. Or completely
remove the existing
paint and prepare
the surface -
cleaning, sanding
and spot-priming
where necessary
- before repainting
with a top quality
latex exterior
paint.
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PEELING
Loss
of paint due to
poor adhesion.
Where there is
a primer and top
coat, or multiple
coats of paint,
peeling may involve
some or all coats.
Where there are
many layers of
old paint (say
1/16” or
about 15 coats),
two peeling problems
can result: peeling
and cracking.
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POSSIBLE
CAUSES:
- Seepage
of moisture through
un-caulked joints,
worn caulk or
leaks in roof
or walls.
- Excess
moisture escaping
through the exterior
walls (more likely
if paint is oil-based).
- Inadequate
surface preparation.
- Use
of lower quality
paint.
- Applying
an oil-based
paint over a
wet or damp surface.
- Earlier
blistering of
paint (see Blistering).
- Old
paint gets brittle,
the contraction
of a new coat
of paint as it
dries and the
movement of the
newer more flexible
paints with the
temperature changes
can crack and
peel the older
coats.
SOLUTION:
- Try
to identify and
eliminate source
of moisture.
The most common
source of dampness
is professional
painters priming
and painting
before the surface
is completely
dry. Every morning
the walls are
covered with
dew, and every
morning the professionals
are out painting
wet walls.
- Prepare
surface by removing
all loose paint
with scraper
or stiff wire
brush, sand rough
edges, and apply
appropriate primer.
Repaint with
a top quality
acrylic latex
exterior paint
for best adhesion
and water resistance.
For best results
strip old paint
completely and
start fresh with
bright freshly
sanded and dry
old wood.
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POOR
ALKALI RESISTANCE
Color
loss and overall
deterioration of
paint film on fresh
masonry.
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POSSIBLE
CAUSES:
- Oil-based
paint or vinyl
acrylic latex
paint was applied
to new masonry
that has not
cured for a full
year. Fresh masonry
is likely to
contain lime
which is very
alkaline. Until
the lime has
a chance to react
with carbon dioxide
from the air,
the alkalinity
of the masonry
remains so high
that it can attack
the integrity
of the paint
film.
SOLUTION:
- Allow
masonry surfaces
to cure for at
least 30 days,
and ideally for
a full year,
before painting.
If this is not
possible, the
painter should
apply a quality,
alkali-resistance
sealer or latex
primer, followed
by a top quality
100 percent acrylic
latex exterior
paint. The acrylic
binder in these
paints resists
alkali attack.
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POOR
GALVANIZED METAL
ADHESION
Paint
that has lost its
adhesion to a galvanized
metal substrate.
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POSSIBLE
CAUSES:
- Improper
surface preparation,
such as inadequate
rust removal.
- Failure
to apply a primer
before application
of an oil-based
or vinyl latex
paint.
- Failure
to sand baked-on
enamel finishes
or glossy surfaces
before painting.
SOLUTION:
- Any
rust on the metal
should be removed
with a wire brush;
then, an acrylic
latex corrosion-inhibitive
primer should
be applied (one
coat is usually
sufficient).
Previously painted
galvanized metal
that is completely
rust-free can
be painted without
applying a primer.
A latex metal
primer should
be applied to
unpainted galvanized
metal, followed
by a top quality
exterior acrylic
latex paint.
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POOR GLOSS RETENTION
Deterioration
of the paint film,
resulting in execessive
or rapid loss of
luster of the top
coat.
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POSSIBLE
CAUSES:
- Use
of an interior
paint outdoors.
- Use
of a lower quality
paint.
- Use
of a gloss alkyd
or oil-based
paint in areas
of direct sunlight.
SOLUTION:
- Direct
sunshine can
degrade the binder
and pigment of
a paint, causing
it to chalk and
lose its gloss.
While all types
of paint will
lose some degree
of luster over
tim, lower quality
paints will generally
lose gloss much
earlier than
better grades.
The binder in
top quality acrylic
latex paints
is especially
resistance to
UV radiation,
while oil and
alkyd binders
actually absorb
the radiation,
causing the binders
to break down.
Surface preparation
for a coating
showing poor
gloss retention
should be similar
to that used
for chalking
surfaces (see
Chalking).
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SURFACTANT LEACHING
Concentration
of water-soluble
ingredients on
latex paint, creating
a blotchy, sometimes
glossy appearance,
often with a tan
or brownish cast.
More likely with
tinted paints than
with white or factory-colored
paints.
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POSSIBLE
CAUSES:
- Painting
in cool, humid
conditions or
just before they
occur. The longer
drying time allows
the paint's water-soluble
ingredients -
which would normally
evaporate, or
be leached out
by rain or dew
- to rise to
the surface before
paint thoroughly
dries.
- Mist,
dew or other
moisture drying
on the painted
surface shortly
after it has
dried.
SOLUTION:
- Avoid
painting in the
late afternoon
if cool, damp
conditions are
expected in the
evening or overnight.
If the problem
occurs in the
first day or
so after the
paint is applied,
the water-soluble
material can
sometimes be
rinsed off rather
easily. Fortunately,
even more stubborn
cases will generally
weather off in
a month or so.
Sufactant leaching
should not affect
the ultimate
durability of
the coating.
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TANNIN
STAINING
Brownish
or tan discoloration
on the paint surface
due to migration
of tannins from
the substrate through
the paint film.
Typically occurs
on "staining
woods," such
as redwood, cedar
and mahogany, or
over painted knots
in certain other
wood species.
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POSSIBLE
CAUSES:
- Failure
to adequately
prime and seal
the surface before
applying the
paint.
- Use
of a primer that
is not sufficiently
stain-resistant.
- Excess
moisture escaping
through the exterior
walls, which
can carry the
stain to the
paint surface.
SOLUTION:
- Correct
any possible
sources of excess
moisture (see
Efflorescence
and Mottling).
After thoroughly
cleaning the
surface, apply
a high quality
stain- resistant
oil-based or
acrylic latex
primer. Oil-based
stain-resistant
primers are the
best type to
use on severely
staining boards.
In extreme cases,
a second coat
of primer can
be applied after
the first has
died thoroughly.
Finish with a
top quality latex
paint.
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VINYL
SIDING WARP
Warping
or buckling of
vinyl siding panels
that have been
repainted.
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POSSIBLE
CAUSES:
- Most
likely cause
is that vinyl
siding was painted
with a darker
color paint than
the original
color. Dark paint
tends to absorb
the heat of the
sun, transferring
it to the substrate.
When vinyl siding
expands dramatically,
it is not able
to contract to
its original
dimensions.
SOLUTION:
- Paint
vinyl siding
in a shade no
darker than the
original. Whites,
off-whites, pastels
and other very
light colors
are good choices.
Top quality acrylic
latex paint is
the best type
of paint to use
on vinyl siding,
because the superior
flexibility of
the paint film
enables it to
withstand the
stress of expansion
and contraction
cycles cause
by outdoor temperature
changes.
- Siding
that has warped
or buckled should
be assessed by
a siding or home
repaint contractor
to determine
the best remedy.
The siding may
have to be replaced.
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WAX
BLEED
Stains
that come from
waxy substance
in the reconstituted
wood products used
to make hardboard
siding. When the
substrate is painted,
these staining
substances bleed
through the paint;
they can even bleed
through some ordinary
primers, possibly
causing dirt pickup,
mildew and/or poor
paint adhesion
(see Dirt Pickup
and Mildew).
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POSSIBLE
CAUSES:
- Failure
to apply a proper
primer to hardboard
before applying
the top coat.
- Allowing
hardboard siding
to weather before
being painted.
SOLUTION:
- To
treat or prevent,
apply a quality
exterior acrylic
latex primer;
follow with a
coat of high
quality exterior
acrylic latex
paint. The American
Hardboard Association
recommends two
coat of top quality
acrylic exterior
house paint for
best results.
Some hardboard
grades have adequate
factory primer
and need only
a quality paint
applied. Low
quality, highly
pigmented flat
paints are more
prone to wax
bleed than are
higher quality
paints.
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WRINKLING
A
rough, crinkled
paint surface occurring
when paint forms
a "skin."
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POSSIBLE
CAUSES:
- Paint
is applied in
direct sunlight.
Sun can cause
the top of the
paint to bake
dry while the
under layer remains
moist. When the
under layer does
finally dry it
shrinks and can
cause wrinkles
in the upper
layers.
SOLUTION:
- Scrape
or sand substrate
to remove wrinkled
coating. Hand
scrub with TSP
solution hot
to warm water.
Use a stiff brush
and wash from
the bottom of
the house up,
so residue does
not streak down
the siding. After
scrubbing an
area, rinse immediately
with a garden
hose before it
has a chance
to dry.
- Repaint,
applying an even
coat of top quality
exterior paint.
Make sure the
first coat or
primer is dry
before applying
the top coat.
Apply paints
at the manufacturer's
recommended spread
rate (two coats
at the recommended
spread rate are
better than one
thick coat).
When painting
during extremely
hot, cool or
damp weather,
allow extra time
for the paint
to dry completely.
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