Overview: Build a paver patio with less work
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Concrete patio
Concrete patios are typically plain and often show cracks.
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Patio after setting pavers
Pavers dress up the patio and make it an attractive outdoor living space.
A concrete patio is made for practicality, not beauty. It starts out looking plain and goes
downhill from there. As craters, cracks and
stains accumulate, it can go from dull to downright
ugly in just a few years. But there's a simple solution,
whether you want to dress up a bland patio or hide an
aging one. Covering concrete with paver bricks is much
easier than pouring new concrete or laying pavers the
traditional way. It requires less skill and less time, and
it's a whole lot easier on your back.
Assess your slab
This project will work with most patios. Surface
damage like flaking, chips and craters is no problem.
But a few conditions make this method a no-go:
- A too-low threshold. Door thresholds have to be high
enough above the existing patio to allow for the
thickness of the border pavers, plus an extra 3/4 in.
to allow for “frost heave”—rising of the slab when
the soil freezes.
- Expanding cracks. This method will work over most
cracks—which grow and shrink with seasonal ground
movement. But if you have a crack that has noticeably
grown in recent years,
this method is risky. The
crack may eventually “telegraph”
through the pavers, creating a hump
or gaps.
Note:
- Search for “patio” or “path” to find paving projects
galore.
- Cool your scorching deck or patio! Search for “shade”
to see ideas and projects.
- Search for “patio furniture” and get complete plans
for chairs and tables.
Comparison: Workload for a standard paver patio and workload
for covering a concrete patio with pavers.
Save 12 Tons of Toil
A standard paver patio rests on a thick
base of compacted gravel. This patio
cover-up will save you the cost of that gravel. More important, it eliminates the
backbreaking drudgery of breaking up concrete, digging up soil, hauling it all away
and hauling in gravel. On this 12 x 14-ft. patio, a patio tear-out and new gravel base
would have meant more than 12 extra tons of wheelbarrow work.
Step 1: Assemble the materials
The materials for this 12 x 14-ft. patio
cost about $850, or $5 per sq. ft. Using
less expensive pavers, you could cut
the cost by almost half. Most landscape
suppliers and home centers
stock all the materials, but you
may have to do a little hunting
for the right combination of pavers.
The pavers used for the border must be
at least 3/4 in. thicker than the “field”
pavers, which cover the area between
the borders. That thickness difference
will allow for a bed of sand under the
field. A difference of more than 3/4 in.
is fine; you'll just need a little more
sand. If you can't find thick pavers
you like, consider retaining wall cap
blocks for the border. We used cement
pavers for the border and clay pavers
for the field.
To estimate how much sand you'll
need, grab your calculator. First determine
the square footage of the sand
bed. Then divide that number by 12
for a 1-in. bed or 18 for a 3/4-in. bed.
That will tell you how many cubic feet
of sand to get. You can have a load of
sand delivered or save the delivery fee
by picking up a load yourself with a
truck or trailer. Most home centers
also sell bagged sand. A 50-lb. bag
(1/2 cu. ft.) costs about $3.
Figure A: Pavers over concrete details
Figure A: Pavers Over a Concrete Slab
This technique requires two types of pavers. Glue thicker pavers to the concrete on the perimeter and lay thinner pavers on a sand bed.
Step 2: Lay the border first
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Photo 1: Scrub the perimeter
Clean the
edges of the
patio where
you'll later
glue down the
border pavers.
Clean concrete
means a
stronger glue
bond.
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Photo 2: Glue down the border pavers
After setting each paver, run a bead of construction adhesive up the side of it. That
will keep the sand from washing out between pavers.
To get started, scrub the border area
(Photo 1) with a concrete cleaner or
muriatic acid mixed with water
(check the label for mixing and
safety instructions). Any stiff brush
will do, but a deck stripping brush on a broom handle makes it
easier. Hose down the patio when
you're done scrubbing the border.
While the concrete is drying, grab
a tape measure and a chalk line
and carefully plan the locations of
the borders (see Figure B). Using the
chalk lines as a guide, glue down
the border pavers along the house
and two sides of the patio (Photo 2).
We used polyurethane construction
adhesive for a strong, long-lasting
bond (about $5 per 10-oz. tube). If adhesive
squishes up between pavers, don't
try to wipe it off. Just let it harden,
then trim it off with a utility knife.
Figure B: Border Layout
A Snap a chalk line parallel to the house
to mark the location of the border pavers.
Remember to leave a gap of at least 1/4 in.
between the border pavers and the house.
B Lay out field pavers to locate the side
borders. A simple row of pavers will work
even if you plan to lay them later in a “herringbone”
pattern as we did. The goal is
to establish a field width that allows each
course to end with a full or half paver, but
not smaller pieces. That means less cutting,
less waste and a neater look.
C Position the border pavers and mark
their locations. It's OK if the border pavers
don't quite reach the edge of the patio, but
don't let them overhang. Nudge one border
outward by 1/4 in. to allow a little extra
space for the field pavers.
D Snap a chalk line to mark one side border.
To make this line square with the line
along the house, use the 3-4-5 method.
E Mark the other side border. Measure
from the first side to make sure the two
sides are parallel.
F Leave the final border unmarked and
install the border after the field is complete.
That open end makes screeding off
the excess sand easier and lets you position
the final border perfectly.
Step 3: Spread a flat bed of sand
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Photo 3: Spread fabric, then sand
Lay down landscape
fabric to keep the sand
from washing down
into cracks. Then position
the screed pipe
and spread the sand.
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Photo 4: Flatten the sand
Notch one end of a
2x6 to match the
depth of the field pavers.
The other end rides
on the screed pipe.
Screed both halves of
the field, moving your
screed pipe as you go.
If the field area is more than 10 ft.
wide, you'll need a screed pipe in
the center of the patio (Photo 3). A
10-ft. section of black or galvanized
steel plumbing pipe ($14) works
best. For a 1-in. bed, use 3/4-in.
pipe; for a 3/4-in. bed, use 1/2-in.
pipe. Keep in mind that each pipe size is
listed by its inner diameter, but the outer
diameter is what matters here: 3/4-in. pipe
has an outer diameter of about 1-1/8 in.;
1/2-in. pipe, about 5/8 in. In both cases,
you'll get an extra 1/8 in. of sand bed thickness
and the field pavers will stand about
1/8 in. above the border pavers. Then,
when you “tamp” the field with a
plate compactor, the sand will compact
and the field pavers will settle
flush with the border.
“Screed” the sand flat with a
notched 2x6 (Photo 4). The depth of
the notch should be 1/8 in. less than
the thickness of the field pavers.
If the field is less than 10 ft. wide,
notch both ends of the screed board
and skip the pipe. Screeding is hard
work and it's best to have a helper.
Step 4: Lay the pavers and finish the border
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Photo 5: Lay the pavers
Cover the sand with field pavers. When the field is complete, glue down the final
border pavers. Then tamp the field with a plate compactor and sweep sand over
the pavers to fill in the gaps.
From here on out, this is mostly a
standard paver job. Lay the field
pavers as you would on any paver
patio. Scrape away the excess sand
and cut off the excess landscape
fabric with a utility knife. Glue
down the last border. Let the glue
dry for a few hours before you tamp
the field pavers and sweep sand
across the patio to fill the joints.
Common Questions
Q: Why not skip the sand and glue down all the pavers?
A: You could do that. But gluing down
hundreds of pavers will add a few hours to
the job and you'll spend at least $100 on
adhesive.
Q: I want a bigger patio. Can the pavers
extend beyond the current footprint?
A: The pavers could continue onto a standard
gravel base. But the gravel base and
the existing slab might shift in different
ways, creating a gap or hump where they
meet. So it's best to keep them separate. If
you want to add a grilling area, for example,
separate it from the main patio and set
a steppingstone or two between the two
paved areas.
Q: Can I glue pavers over the steps?
A: Yes. If your patio includes steps, you
must cover the treads in order to maintain
the height of the steps. Or you can
completely cover the steps if you like. Just
be sure to leave a gap of at least 1/2 in.
between the pavers on the steps and those
on the patio to allow for movement.
Q: Do I have to use paver bricks?
A: You can cover the field with any type of
paving product: natural or manufactured
flagstone, pavers of any size or shape.
But paver bricks are best for the border
because they provide a flat, even surface
for screeding (see Photo 4).
