BUILDING
THE CONCRETE FORMS:
At entryways, for better appearance and easier access, use curved
forms to provide curved entryways on both sides where the driveway
meets the street. Use 1/4-inch plywood cut in widths to match the
concrete depth dimension and stake the plywood as it is bent into
a gentle curve. Use plenty of stakes to prevent the plywood from
bulging when the concrete is placed into the form. Concrete
takes the shape of the mold in which it is placed. In most cases,
the mold is made of 2X4, 2X6, or 2X8 lumber supported by 1X2, 1X4,
or 2X4 stakes.
To
build the form, position two parallel boards in the excavation so
that their inside edges form the driveway sides. Drive stakes in
place next to the ends of the form boards. Starting at the ground
level's highest point, raise the ends of the boards up with their
top edges about 2 inches above ground level. Check for level with
a carpenter's level across the tops of the two form boards. Run
a straightedge across the forms so it bridges them. Then set the
level on the straightedge.
Fasten
the forms to the stakes with duplex (double) headed nails. If the
tops of the stakes are not flush with or slightly below the top
edge of the forms, saw them off once the form is completed. Raise
the opposite ends of the boards up to suit-either following the
contour of the ground or raising them to match the desired pitch.
Then drive stakes, spaced every 3 f. along the form boards and nail
the stakes to the form boards. Install a stake at any location where
two form boards butt. Nail the stake to both boards. If the ends
of the boards are angled or uneven, square them with a saw before
nailing them into position with double-headed nails.
Oil
the form boards with old motor oil applied with a paintbrush. The
oil will prevent the forms from sticking to the concrete. The oil
also prevents water in the concrete from being absorbed by the forms,
thus weakening the concrete mixture.
Once
the forms are in place, including the centered stop board, double-check
all measurements. Then order any necessary reinforcing mesh, cut
it to fit inside the forms, if needed, and elevate it with stones
or brickbats about half the distance from the grade to the top of
the form boards.
NOW,
THE CONCRETE:
When you're satisfied that the forms are ready, order the concrete
for the job. It is strongly recommended that you use a ready-mix
service; the time and work you will save in not mixing the concrete
yourself is worth the added expense. The ready-mix company will
need to know the dimensions of the driveway between the form boards:
the length, the width, and the depth (overall average). The concrete
folks will fill your order accordingly. Tell them your plans.
If
the driveway will be crowned, you will place one section of concrete
at a time. Tell this to the ready-mix company. Schedule a date for
the pour with the company and be ready when the truck drives up.
It is suggested that you enlist the aid of a couple of friends to
help you with the placement. Once dumped out of the concrete truck,
you'll have to work fast to level the concrete with shovels and
then screed (level) the top with a straightedge. It's hot, heavy,
and fast work.
Start
the pour at the garage and work toward the street. If you lay the
length of the driveway in sections, install a stop board at about
10 feet. It will then correspond to the placement of control joints.
Place the concrete in this first section only.
Tamp
and spade as needed, giving special care to edges and tie bars.
Screed the concrete off (work a straightedge zigzag fashion across
the top of the form boards) and place it into the adjacent, unpoured
section. If you don't screed, some places will have a lot of extra
concrete, which must be moved. Other spots won't have enough.
Let
the slab set up. Cut any control joints as needed, insert any expansion
strips, and give the driveway a lightly broomed finish after you
float and finish-trowel the surface fairly smooth.
The
Final Pour-
Once the first half of the slab is finished, remove the stop board.
This is not easy. It is hard to slip the tie bars back through the
holes in the stop board. Repeat the entire process for the remainder
of the driveway, in 10-f. sections as needed to complete the driveway.
Curing-
The concrete should be covered with burlap and the burlap kept wet
for a week or so with a sprinkler head on a garden hose. You can
skip the burlap, but keep the surface of the concrete wet.
If
it starts raining as you finish the trowel and brooming job, cover
the concrete either with burlap or newspapers so the raindrops don't
dam age the surface of the concrete.
Let
the project set a couple of weeks, then strip off the forms and
backfill any dirt needed to cover the surface of the concrete.
Bull
Float is a little more than a handle with a board attached to it.
The float is pushed and pulled along the concrete surface after
the concrete has been screeded. The float produces a level, but
slightly rough surface, which can then be troweled. You can buy
bull floats or make them yourself. A "hand" float (looks like a
trowel) also is handy.
Procedures
check. To sum up the steps involved in placing a concrete driveway,
use this quick checklist:
1. Find out the codes in your community.
2. Sketch the project, putting in dimensions.
3. Get the necessary building permits.
4. Excavate and prepare the base.
5. Build the forms (4 & 5 can be done together).
6. Double check all measurements.
7. Order the concrete.
8. Finish the concrete.
9. Protect the concrete until it has hardened.
10. Backfill and landscape.
