If you've been putting off renewing your deck because you think it requires a lot
of time, tools and know-how, take heart. In this article, we'll show you how to
clean it up fast with the help of a pressure washer and special products that
help remove dirt, mildew and old finishes. We'll also show you how to apply a fresh
finish, using a foam applicator pad that glides along the wood and quickly applies a nice,
even coat. No more messy rollers and brushes.
This process will work on any wood deck, including redwood, cedar and pressure treated
lumber (but not on composite decks). The only special tools you need are a
pressure washer and a foam applicator pad. The project doesn't require any
special skills. Just set aside at least four hours on one day to clean your deck, and another
four hours several days later to stain it.
The cost of rejuvenating an average-size deck is about $250, including tools, materials
and the pressure washer rental. You'll save several hundred dollars by doing the work
yourself. Having your deck professionally cleaned and stained will cost $500 to $1,000.
Rent a pressure washer
A pressure washer will scour away dirt and
contaminants ingrained in the wood
at the same time it sprays on a deck stripper
to clean off previous finishes.
Rent a pressure washer from a home
center or rental center (about $40 for four
hours, or $70 per day). A pressure setting
of 1,000 to 1,200 psi is ideal. Too much
pressure will damage the wood and make
the wand harder to control.
Rent a unit that allows for the intake of
chemical cleaners (deck stripper and
wood brightener) so you can spray them
on through the wand. Most pressure
washers have an intake hose that draws in
cleaners from a separate bucket. (Use a
plastic bucket. Chemicals in the cleaners
can react to metal buckets.)
We used sodium hydroxide as the deck
stripper. You probably won't be able to
find straight sodium hydroxide, but you
can find a deck stripping product with
sodium hydroxide as the active ingredient
in almost any home center or paint store.
We diluted our stripper to a 50/50 mix
with water. Some sodium hydroxide–based strippers are premixed and don't
require adding water. More commonly,
you need to dilute the stripper with water.
Read the label on the container to find out
what's suggested for your stripper.
Protect your house and plants
Before you begin cleaning, make repairs to
your deck, such as replacing cracked or
split boards and broken balusters.
Then heavily douse the plants or grass
under and around your deck with water
and cover them with plastic. Although
most strippers aren't supposed to harm
vegetation, it's still a good idea to protect
plants and it only takes a few minutes.
Once you've finished cleaning the deck,
immediately remove the plastic.
Also spray down the siding with clean
water to ensure that any stripper that
splashes onto the house will easily wash off.
Scour away the old finish
With a 25- or 30-degree tip in the wand of
the pressure washer and a psi of 1,000 to
1,200, apply the stripper to the deck, starting
with the top rails and working down
the balusters (Photo 1). Spray the rails
with a continuous, controlled motion.
Keep the wand moving so you don't gouge
Once you finish the railings, start on the
deck boards. Wash along the length of the
boards (Photo 2). You'll see the grime
washing off the wood.
Go over stubborn mildew or other stains
a few times rather than turning up the
pressure or trying to heavily scour the
wood. Later we'll tackle tough stains that
won't come out with the stripper.
This stripping process washes away a
small amount of the wood's lignin, which
is the glue holding the wood fibers
together. As the lignin washes away, the
fibers stand up, giving the wood a fuzzy
appearance. Don't bother sanding off the
fuzzy fibers. They will gradually shear off
and blow away.
After you've power-washed the entire
deck, rinse all of the wood with plain
water to dilute and neutralize the stripper.
If there's still debris trapped between deck
boards, such as leaves or twigs, remove it
now (Photo 3).
Brighten the wood
A deck brightener will return the wood to
its newly sawn color and make it more
receptive to the stain. Use an oxalic
acid–based brightener, which is available at
home centers and paint stores. It works fast, won't harm the
wood and is environmentally safe in the
diluted solution that you'll use.
Like strippers, some deck brighteners
come premixed and some need to be
diluted with water. Read the label for the
manufacturer's recommendations. We
mixed our oxalic acid with an equal
amount of water and ran it through the
pressure washer's intake hose.
Change the tip in the wand of the pressure
washer to a fan tip with a 40- or
45-degree angle. Then set the pressure to
about 1,000 psi and spray the deck, once
again starting with the top rails and
working down to the deck boards. Apply
just enough brightener to thoroughly wet
Oxalic acid will brighten the wood in a
matter of minutes and does not require
rinsing. But your siding does. Rinse off
your siding with clean water at very low
pressure (about 500 psi) to wash away any
stripper or brightener overspray (Photo 4).
If your wood is cedar or redwood,
you'll see a dramatic difference as the
wood brightens to its fresh sawn color.
Our deck is pressure-treated pine, so the
brightening of the wood is less noticeable.
Inspect the whole deck
With the deck clean, it's easy to spot any
areas that need additional maintenance.
Drive any nail heads that are popping up
until they're flush with the deck boards.
Look for missing or loose screws, and
replace them with corrosion-resistant
screws that are slightly longer than the
original (Photo 5). Replace missing nails
with corrosion-resistant “trim head ”
screws, which are screws that have a small
head and resemble a large finish nail.
If lag screws or bolts are loose in the
ledger board, rails or posts, tighten them.
Inspect the flashing between your deck and
house to ensure it's still firmly in place.
Attack stubborn stains
Although the sodium hydroxide in the
deck cleaner will remove most stains and
mold, particularly stubborn ones require
Use a non-chlorine laundry bleach to
remove the stain. (This works especially
well if the stain is from mold, mildew or
algae.) Apply it to the affected area, then
scrub with a nylon brush. Rinse the area
For tougher stains, use trisodium phosphate
substitute. Mix the TSP substitute
with water and apply it to the stain. Let it
sit for a minute or two, then scrub with
a nylon brush and rinse with water
To remove deep stains that don't come
out with TSP substitute, let the deck dry.
These “bleed” stains are often caused by
fasteners. Sand the stains out, using
80-grit sandpaper and concentrating only
on the affected areas. Some bleeds may be
too deep to sand out. Rough or splintered
areas may also need sanding. Spot-sand
working in the direction of the wood grain
until the surface is smooth (Photo 7).
Wear a dust mask, and sand only if the
stain bothers you. You don't have to get
every stain out. After all, imperfections are
part of an outdoor deck.
Back to Top
Apply the finish—finally!
The deck will need a minimum of 48
hours to dry after the cleaning. If it
rains, wait two more days for the wood to
dry. Avoid staining in high heat, high
humidity and in direct sunlight. Perfect
conditions are an overcast day with the
temperature in the 70s and no possibility
Start by staining the top rails and working
down the balusters and posts (Photo
8). Run the applicator pad down the
length of the wood, applying the stain in a
steady, uniform manner. Don't go back
over areas that are already stained. Unlike
paint, stain gets darker with each coat.
If stain drips onto the deck, smooth it
with the applicator pad to avoid spotting.
Once the railings are complete, stain the
deck boards. Load the pad with plenty of
stain, yet not so much that it drips. Start
by carefully “cutting in” stain along the
house. If stain drips onto the siding,
promptly wipe it off using a clean cloth
and mineral spirits or paint thinner.
Attach a broom handle to the applicator
pad. Glide the pad along the length of the
deck boards, staining with the grain
(Photo 9). Stop only at the end of a
board. Otherwise, the overlap where you
stopped and started could be noticeable.
Once the deck is finished, apply stain
to the stair treads, working your way
down the stairs.
Finally, use a paintbrush or spray bottle
to work stain into tight areas that the
applicator pad couldn't reach, such as lattice
and crevices between balusters and
the rim joist (Photo 10).
Allow the stain to dry at least 48 hours
before walking on it. Feel the deck to make
sure the stain is completely dry. Likewise,
check the bottom of your shoes before
walking back into the house.
Pressure Washer Safety
To use the pressure washer:
- Wear appropriate safety gear
and clothes. Rubber boots
and gloves will protect your
hands and feet. Safety goggles
will keep the chemicals
from splashing into your
eyes, and a disposable
respirator or dust mask will
- Keep the exhaust from the
pressure washer at least
3 ft. away from any objects,
including your house.
- Practice spraying the water
until you find an appropriate
- Never point the wand at
anything you don't want
- Cover electrical outlets.
Choosing the Best Stain
You have two basic stain choices:
oil-based and water-based. Oil
stains are easier to apply, penetrate
the wood grain and require
less work when you reapply them.
However, they only last two to
Water-based (latex) stains last
four to six years, but they'll eventually
peel and require more prep
work before recoating. Opaque
latex stains generally last longer
than semitransparent versions.
When possible, test the stain
on an inconspicuous section of the
decking. We used a cedar color
that worked well since the wood
was pressure treated and somewhat
dark in color. For a darker
color, a redwood-colored stain is
available, while a honey color is
an option for a lighter, natural
Be careful not to choose a
light color stain if your deck was
previously covered with a dark
stain or is pressure treated (green).
The light stain will not cover the
dark wood or darker stain, and it
will turn gray within a few weeks.
If you want a natural gray or
silver deck, use a clear finish. It will
protect the deck from mildew and
algae, but not from the sun, allowing
the deck to start graying in a
month or two.
The following companies offer a full line of
products for cleaning and finishing decks,
including strippers, brighteners and stains.
The products are widely available at home
centers, hardware stores and paint stores.
Each company's Web site features a store
locator to find the company's products.