As
a general rule, the exterior or body of your house should be painted
every 6 to 8 years-or even before this if you note deterioration
of the paint film such as cracking, peeling, faking, fading, and
just plain paint failure, although paint failure can usually be
traced to surface failure (the substratum) rather than the paint.
Paint seldom, if ever, "fails." As
with any paint job, more than 90% or the work involved should be
with preparation of the surface. For paint to adhere properly, it
must be applied to a clean and dry surface-free of dirt, dust, grease,
and flaking paint or other types of paint trouble. The time that
you invest in cleaning, scraping, and patching will make it all
worthwhile. Applying the paint is the easiest part of the painting
project.
Exterior
Paint Finishes-
There are two types: body paint or the finish that you apply to
the siding of the house, and trim paint or the finish that you apply
to doors, windows, gutters, etc. Trim paint is different in that
it is formulated with special resins that dry to a semi-gloss finish
which is easier to keep clean than body paint which is more "elastic"
so it can expand and contact with outside temperature changes. Body
paint (sometimes called "structure" paint) also looks better on
rough surfaces often found on siding: wood, concrete, brick. z
WHAT
TYPE PAINT SHOULD YOU BUY?
Latex finish paint-
It can be used on most surfaces. Some surfaces will require a primer
undercoat. You can buy latex especially formulated for masonry and
aluminum siding. Contrary to popular belief latex may be applied
over exterior oil paint IF the oil paint is tightly bonded to the
surface and deglossed. Latex paint may be applied in temperatures
between 50" and 80°F, and even when the surface to be painted is
slightly damp. The material won't lap. It is almost odorless, thinned
with water, and fade-, fume-, and mildew-resistant. Since it's water-based,
tool clean up can be under the kitchen sink faucet. You can buy
latex in a wide range of pre-mixed colors; prices are comparable
with other types of paint-sometimes even a tad less expensive.
Acrylic
finish paint-
This finish has all the features of latex finish paint, but it dries
faster. It is a type of latex paint in formulation. Its cost is
usually slightly higher than latex finish paint. Like latex, it
may be applied with a brush, roller, pad painter, and spray gun.
Alkyd
finish paint-
It may be applied to any surface but unprimed masonry and metals.
It is thinned with turpentine or mineral spirits; the finish dries
more slowly than latex or acrylic. Alkyd finish is recommended for
chalking surfaces. It may be applied with a brush, roller, or spray
gun.
Oil
finish paint-
It's formulated for most surfaces. It is slow-drying, however, if
this is a consideration and it is solvent tinned. It may be brushed,
rolled, or sprayed on the surface.
Trim
paint-
It's available in the Big 4: latex, acrylic, alkyd, or oil finishes.
It is made for windows, doors, shutters, fascia and other "trim"
parts of a house. In latex, you can buy it color-matched to body
paint. This is called a "latex system".
Masonry
finish paint-
Latex is excellent. So is Portland cement mixtures and alkyd and
epoxy.
Porches/decks/steps-
They use a finish called "porch & deck" enamel. It can be latex,
acrylic, alkyd, oil, rubber, polyurethane. It can be applied with
a brush, roller, floor brush, or a squeegee. Check the label on
the container for specific, special data.
Exterior
Stain-
It's available for wood shakes and shingles, plywood siding, panel
siding, decks, and outdoor furniture pieces. There are two types:
semitransparent if you want to see the wood under the stain, and
pigmented if you don't want to see much of the wood under the stain.
Buy pigmented stain for plywood siding. The "plugs" in plywood siding
are synthetic and will not take semi-transparent stain without showing
the plug.
Primers-
They are especially formulated for both old and new wood and metal.
Use a primer instead of thinning finish paint. You will be dollars
ahead if you do, since thinning finish paint dilutes it so it doesn't
furnish the best bonding surface as a primer does.
Plastic
finishes-
Use marine formulated paints on fiberglass. Do not paint other types
of plastic. The results could be very disappointing.
Wood
roofs-
The finish should be a water-repellent preservative. Never paint
a wood roof with standard paint. Wood roofs hold moisture; the paint
will pop off the surface and cause a mess. If you want to change
the color of a wood roof, use a semi-trans parent stain. Brush it
on.
Asphalt
roofs-
Use an asphalt bituminous roof coating only. A solvent-thinned paint
will dissolve the shingles. You will need at least two coats of
finish to cover the roof surface. Sometimes three coats are necessary.
Brush, roll, spray.
Metal
roofs-
They can be painted with most any metal paint. The roof must be
cleaned and primed, however, for best results. Do no use standard
paint; it will pop off the metal due to moisture. If the metal is
terne, a tin-steel alloy, use an iron-oxide primer. The finish paint
can be latex or alkyd.
