Overview: Benefits and savings
Mother Nature is
tough on asphalt.
Sunlight breaks down the surface,
creating pits and cracks. Then water
seeps in, expands the cracks and
erodes the gravel base below. Left
alone, an asphalt driveway becomes a
crumbling eyesore in about 15 years.
But with a little maintenance, you can
double the life of your driveway and
save thousands in replacement costs.
Most driveways are big and conspicuous. And a long stretch
of gray, cracking asphalt can give a home a scruffy look,
no matter how handsome the rest of the property is. So a
fresh coat of shiny black sealer isn't just protection against
expensive driveway damage—it's a face-lift for your home
You can keep your asphalt in tip-top shape by following
the three steps we show here. Asphalt maintenance
doesn't require special skills, and you'll only need a few
inexpensive tools. You can get everything you need at home
centers and hardware stores. However, as with exterior
painting, high-quality results hinge on some sweat and careful
prep work. Expect to spend about six to eight hours completing
the job. To fill cracks and seal coat an average driveway
(750 sq. ft.), you'll spend $100 to $150 on materials.
That's about half what a pro would charge.
Step 1: Fill cracks every year
Maintaining the asphalt skin is the best thing you can do to
preserve your driveway. The asphalt layer serves primarily
as a protective skin over the gravel base. The weight of your
car is supported by the base, not the asphalt. If too much
water gets through, the base erodes, causing additional
cracking, potholes and total asphalt breakup.
The best way to keep the asphalt skin intact is to fill
cracks, ideally every spring. Buy the high-quality pouring type
filler. Read the labels. Our experts recommend
the ones containing rubber compounds. They typically
handle cracks from 1/8 in. to 1/2 in. wide. For smaller
cracks, small tubes of filler in a caulking gun are easier
to use. For larger cracks, 1/2 to 3/4 in. wide, buy an extra thick
filler that you spread with a trowel, or tamp in asphalt
Fillers adhere to the sides of cracks, so your first task is to
clean out the dirt and old, loose filler 1/2 in. to 1 in. deep.
This is time-consuming. Use a screwdriver or a 5-in-1 tool
shown in Photo 2) for the packed areas. Go deeper if weeds
have taken hold. If you don't get all their roots, they'll grow
right up through the new filler. Tip: A week before you
begin this project, apply a nonselective herbicide to kill
roots. Clean the crack edges (Photo 1). You can use a pressure
washer or a garden hose, but then let the driveway dry for
at least a day before filling.
Fillers need at least 24 hours to dry, so don't fill cracks
when rain is in the forecast. The filling technique varies
with the product, so check the directions. With most products,
you can simply pour the filler into cracks up to 1/4 in.
wide. For wider cracks, stuff in backer rod first (Photo 2).
Backer rod is available in several thicknesses at home centers at a low cost.
Neatness counts when you're filling cracks (Photo 3). The
jet-black filler contrasts with the gray asphalt and can look
bad if you overfill or smear it.
Cracks that form a spider web pattern in a small area usually indicate that the base has softened. Water will settle in
this spot and make the problem worse. Fillers will help for
a while, but sooner or later you'll have to cut out and patch
the cracked area. Cut the asphalt using a diamond blade in your circular saw (Photo 4). Then repack the gravel
base by pounding it with a 6-ft. 4x4 or a hand tamper.
Fill the cutout and pack with a 4x4 or hand tamper (Photo 5).
You can buy asphalt patching material at
home centers and hardware stores, but it isn't nearly as
durable as regular hot asphalt. For better performance, seal
coat the patch after about six months. And for areas larger
than a few square feet, we recommend that you hire a pro.
(See “Talk to a Pro,” below.)
Step 2: Restore edges every two years
Asphalt edges are especially prone to cracking because the
base erodes at edges more easily. Grass invades the cracks
and increases erosion. So every other year, grab a shovel or
lawn edger and cut back the grass (Photo 6). Then clean out
and fill the cracks.
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Step 3: Seal coat every four to five years
The purpose of a seal coat is to protect the asphalt against
sun and water and to fill small cracks. It also dresses up the
asphalt by covering fillers and patches. You don't need to
do it every year. In fact, seal coat will peel if there are too
many layers, and you'll permanently ruin the appearance of
Home centers carry several sealers. Buy the best one (the most expensive!), especially if
you're sealing your driveway for the first time. A better sealer
means better long-term adhesion. Adhesion is vital,
because you'll apply more coats in future years, and each
fresh coat is only as good as the coat beneath it.
To ensure good sealer adhesion, the driveway must be
clean and dry. Fill cracks and edge the driveway at least a
week in advance. Scrub with a stiff broom. Then sweep or
blow debris off with a leaf blower. You can use a garden hose
or a pressure washer, but you'll have to wait for it to dry.
Sealer won't stick to oily
spots left by a drippy car.
First scrape off the oily gunk
with a putty knife. Then
apply a detergent (such as
dishwashing liquid) or buy
the sealer manufacturer's
cleaner and scrub. After you
rinse, examine the spot. If you see an oil film on the rinse
water or if water beads up on the spot, scrub again. You can
wash the entire driveway surface at this time, since you'll
have to wait one or two days for the asphalt to dry anyway.
When it's dry, apply primer (Photo 7) to the spots.
Before you apply sealer, check the weather forecast and
the sealer's label to make sure you'll get good drying conditions.
Seal coats are water-based, and a rainfall before they
dry will ruin them. Drying times will slow in cooler and
more humid conditions.
Tip: If you're a rookie, work on a
cooler, more humid day to slow
drying so you have more time to
spread the sealer smoothly.
Coat the edges first using a stiff brush such as a masonry
brush (Photo 8). Then coat the entire driveway using a
seal coating broom or squeegee (Photo 9). Stir the sealer
before application even if the label claims it's a no-mix formula.
Seal coating isn't difficult, but it is messy. Wear old
shoes and clothing you can toss. The worst mistake is stepping
in drips, then tracking the seal coat across concrete or
inside your home.
Be sure to read the manufacturer's directions and follow
the recommended spread rate. Take care not to lay it on too
thick. Puddles or thick areas will probably peel. Work the
sealer into the surface. Although some sealers require only
one coat, it's better to have two thin coats than one thick
coat. And you're less likely to leave ridges or brush marks.
Finally, surround the driveway with stakes and string or
tape. Keep everyone, including pets, off the finished surface
until it dries. Otherwise you might find black, gooey paw
prints on your kitchen floor!
Large cracked area; job for a pro
Pro repacking the gravel base
Talk to a Pro
Before diving into an asphalt driveway repair project, call in a
local pro for an estimate. (Search online or look in your yellow pages under
“Asphalt.”) That way, you can compare the estimate with the cost
of doing it yourself. The tools and materials purchased from a
local home center for our 700-sq.-ft. driveway cost about $130.
The pro bid was $300. Keep in mind that a quality professional
job will include hot-melt crack filler and hot asphalt patching
material. These materials provide longer-lasting repairs than you
can make yourself. And if your driveway has lots of heavily
cracked areas or large potholes, the gravel base probably needs
repair; that's a job best left to pros.
If you decide to hire a contractor, avoid those who give bids
over the phone. Good contractors will examine your driveway
and give you a detailed bid. They should also tell you the products
they'll use and all the steps in their process. Seal coating
warranties are often for no more than a year. But patches should
be guaranteed for the life of the driveway.