A lot depends on your taste. The newer resurfacing
products are dubious. I've heard of them peeling. And
they're water-base, which is never good outside. From
the samples I've seen, they also don't look very good.
Stains: *Do not use water-base exterior stain. It's
basically just watered down latex paint and will wear
away in less than a season.*
I use Cabot's solid oil deck stain on
our deck, but I'm not sure that's still available. Due
to changes in EPA reguation, oil base deck stains don't
have enough drier, making semi-transparent dry slowly
while solid has been pretty much discontinued. That
means there is no usable solid color product for exterior
except urethane reinforced alkyd paint. Don't use that.
It's not a good idea on old wood. Even on fresh wood, it
will eventually peel and then it's a nightmare to scrape.
But if you *can* find true solid, alkyd (oil base) deck stain,
that's the best option for looks and wear. It will peel a bit
over time, but it's easy to scrape and recoat.
So what's left, otherwise? Semi-transparent stains and
transparent alkyd stains. The trouble with those is that
they won't provide color coverage. On old, gray wood,
whether you get a "cedar" red-orange or a blue-green, it
will look gray and muddy on top of grayed deck boards.
But it will at least protect the wood. People make the
mistake of thinking PT lumber doesn't need to be stained.
It does. Besides being ugly, it breaks up and cracks with
Some of the companies selling oil-base deck stain don't
recommend 2 coats because of the EPA-required lack of
drier. I recently did a fence with Benj. Moore's version of
Australian Timber Oil and the clerk at the paint store insisted
I couldn't do 2 coats because it would never dry. I asked if
she'd recommend Japan drier. She got angry! Benjamin Moore
can't put in enough drier, according to the paint clerk. But
they have no business saying only one coat can be used.
One coat doesn't provide even coverage. They're apparently
just saying it because they don't want complaints from
customers about long drying times.
(Note, also, that Benjamin Moore was bought out by
Warren buffet's Berkshire Hathaway. Buffet is not in the
paint business. He's in the money business.)
Anyway, I used 2 coats of the Moore "timber oil"
stain and didn't have a problem. But with a thick
coat on a horizontal surface you might wait days for
semi-transparent or "semi-solid" to dry.
The problem with most paints these days, especially
exterior, is that technology has not caught up with fume
regulations. There's no such thing as a high quality water
base trim paint for interior. It just doesn't settle well and
it's soft. (I've been experimenting with "waterborne" alkyd
paints for interior trim, but at this point I'm going back to
using oil, despite only being able to buy quarts. The
waterborne alkyd is very thin and scratches *very* easily.)
There's no such thing as a water base *anything*
that can stand up to moisture outside. It's fine for body stain,
but not for trim. (The paint companies know that. They often
recommend oil base primer.) Water base deck stain is the
worst joke of all. It doesn't peel, at least. It just wears off
after a few times walking over it. And it's a flat finish, so it
shows dirt and scuff marks badly.
If you're feeling ambitious, you can experiment. I've had good
luck in the past with a blend of gloss exterior oil paint, boiled
linseed oil and paint thinner. The paint provides color and
driers. Linseed oil is what's used to seal wood gutters and
used to be used on decks/steps. The result is a glossy,
solid stain. But try it first to make sure you like the result.
Exterior oil paint isn't what it used to be, but the linseed oil
is the main ingredient, so that shouldn't really matter.
Wood: A better solution would be to replace the wood
and then stain that. (Wait until late Fall or next Spring
for PT.) You could use 1 1/4x6 PT decking. That should
be the cheapest. I like 1x4 "mahogany". It looks much nicer
and is usually cheaper than fir. It also soaks up the stain
1x4, fir or mahogany, gives you a more elegant
look that you just can't get with PT. PT looks utilitarian, like
a boat dock. Fir and mahogany are finer, planed woods that
give the appearance of a porch. The plastic decking, like
Trexx, is another option, if you like it. It's fairly expensive.
Personally I think it looks tacky and ugly. Like vinyl siding,
it works, but you can never make it look good. Ironically,
Trexx was originally marketed as an environmental product,
recycling plastic milk bottles. But since it doesn't break
down well it's not a recyclable product. And the colors are
less than inspiring. The choices seem to be basically shades
of dog food or plasticky gray. (I repaired a plastic-composite
deck railing recently, and actually, that was so ugly that I
didn't really notice how ugly the floor was. :)
1 1/4 x 6 cedar is also nice, if you can find it, but it's
And of ocurse, if you have a railing on your deck that will
also affect options, at least aesthetically.