Replace a concrete pad.
In most cases, replacing a small pad doesn't require wire mesh, gravel fill, or even packing down the soil. However, be prepared to add fill or even regrade your yard to solve any drainage problems.
Except for the hammer drill, the tools you'll need are inexpensive enough that you may just want to buy them, even though most are available for rental. For small pads like this, you'll usually need less than 1 yd. (27 cu. ft.) of concrete. Still, we strongly recommend that you buy ready-mix concrete and have it delivered rather than mix it bag by bag. One yard of concrete delivered will cost $80 to $95, but expect to pay an extra $50 to $90 "minimum-load" charge.
To strengthen the concrete mix and lessen the chance of cracking, ask the concrete company to add "fiber mesh" to your mix. To figure out how much concrete you'll need: One yard (27 cu. ft.) is enough for a 54-sq.-ft., 6-in. thick pad, or an 81-sq.-ft., 4-in. thick pad. Plan on pouring a pad at least 4 in. thick.
A LITTLE EXTRA INSURANCE
In these photos, we show you how to pour a pad that will never sink or dip toward the house. The key is to install rebar to attach the pad to the home's foundation (see Photo 3). It isn't always necessary, but it's good insurance.
Before you go the extra mile, check with a local building inspector. Although this type of work rarely requires a building permit, attaching the pad to the house with rebar may change how your municipality views the work.
Pay attention to the weather forecast when you're doing finish concrete work. Ideally, the temperature should be between 50 and 80 degrees F. A heavy rain on the first day can be a real bummer. After everything's done and you're the proud parent of a new pad, someone is bound to ask what you did on your weekend. To sound both professional and mysterious, you should reply: "Oh, just a little flatwork."
STEP 1: BREAK UP the old concrete with a sledgehammer and pry it out with a pry bar. To protect your windows and siding from flying chips, cover them with 1/2-in. plywood. Wear goggles to protect your eyes.
STEP 2: LAY OUT the form's three sides (made of straight 2x4s) and screw them together. Take diagonal measurements and adjust the form until the measurements are equal and the form square. Then drive in the wooden stakes (one every 3 ft.) along the outside of the form. Level the back of the form first by screwing it to the stakes (screw-head out). The sides of the form should slope away from the house 1/4 in. for every foot (example: 3/4 in. for a 3-ft. deep pad). With everything just right, finish screwing the stakes to the form.
STEP 3: USE 1/2-IN. rebar, 12 to 18 in. long, to lock the pad in place next to the foundation. To install the rebar, drill 1/2-in. holes 4 in. deep, using a masonry bit and a hammer drill. Then insert the rebar and bend it down (just stomp on the outer end) to lock it in place.
STEP 4: LEVEL THE CONCRETE MIX (the process is called screeding) as you add it to the form. For your screed board, use a straight 2x4 that's 1 ft. longer than the widest part of the form. Work the board from side to side as you pull it from the house outward. The mix should be slightly higher than the top of the form. Poke the mix with a shovel tip to work out air pockets, especially near edges and corners. For a smoother finish on the pad's edges, tap the sides of the form with a hammer.
STEP 5: ROUND OVER THE EDGES, about 15 to 30 minutes after screeding, with an edging tool. This will give initial shape to the edge and force the aggregate away from the corner. Then, round the edges a few more times, during floating and after. For a "framed" look, you can complete this step after the brooming shown in Step 7.
STEP 6: SMOOTH THE CONCRETE with a magnesium (mag) float. The concrete is ready for floating when you can press a finger only about 1/4 in. into it. Kneel on a 2x4 laid across the form to reach hard-to-get-at areas. Make long, sweeping strokes with the leading edge of the float lifted slightly. You should try to finish this step within one hour of starting the pouring, depending on the temperature and humidity. In hot, dry weather, you'll have to work faster.
STEP 7: EXPERIMENT with the broom about 15 minutes after floating. The coarser (more slip-resistant) you want the concrete, the earlier you should broom. If the texture is too coarse, knock the ridges down with the float. Use a concrete broom or stiff-bristled shop broom to make shallow, parallel grooves that follow the direction of the slope. These grooves provide traction and will help prevent flaking, or spalling, later on.
STEP 8: COVER THE PAD with a plastic sheet to slow the curing (hardening) of the concrete. In moderate conditions, wet the pad with a fine spray of water every two to three hours for the first day. Higher temperatures require more frequent wetting. The more time concrete has to cure, the stronger it will be.
SPECIAL TOOLS AND MATERIALS
* Mag float ($8 to $15)
* Concrete broom ($8)
* Edging tool ($6 to $8)
* Hammer drill (one-day rental: $30)
* 1/2-in. masonry bit
* Wooden stakes
* 1-1/2-in. screws
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|Title Annotation:||concrete area outside the front door|
|Publication:||The Family Handyman|
|Article Type:||Brief Article|
|Date:||May 1, 1999|
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