How to Extend Concrete Steps from a House

Colored concrete step extension.

Concrete stairs are an easy way to extend steps from a house where old steps need to be replaced or upgraded. The old structures must be completely removed. The new concrete stairs are built with wooden forms constructed of two-inch lumber cut to size, leveled, braced, and reinforced in place by stakes driven solidly in the ground. Reinforcing steel is placed in the forms to ensure strength. After the forms are leveled and reinforced, concrete is placed in the forms and allowed to partially cure. The forms are then removed, and a final finish is applied to the concrete. .

Things You'll Need

• 2 by 8-inch form lumber
• 1 by 3-inch precut foundation stakes, 2 feet long
• 1 by 3-inch random boards
• 1/2-inch rebar, one piece
• 8-penny duplex ("doubleheader") form nails
• 16-penny duplex ("doubleheader") form nails
• Gypsum layout chalk
• Mason's twine
• Square blade shovel
• 5-pound sledge
• Electrical circular saw
• 16-oz hammer
• Level or leveling device
• Square and other common tools

Instructions

Plan Your Steps to Suit Your House

1. 

   Calculate the measurements necessary.

   Design your stairs to be functional, comfortable, and code compliant. They must be a minimum of 3 feet wide, with risers between 5 inches and 7 1/2 inches. The treads or steps should be between 10 inches and 12 inches wide. A minimum 3 by 3-foot landing must be provided at the top of the stairs in front of a door. Wider steps and curved steps can add appeal.

2. 

   Grading for concrete.

   Level the site and and lay out the stairs on the ground. Next, dig out minimum 12 by 12-inch square footings all the way around the perimeter of the stairs. Be sure the footings are level, square, and clean. Forms of 2 by 8 inches are most commonly used because they provide a 7 1/2-inch riser.

3. 

   Staking forms.

   Frame a 3-sided, U shaped form. Set the form in its final location at the edge of the footings, with the open end against the foundation of the house. Drive 1 by 3-inch foundation stakes vertically into the ground at all form corners and mid points, making sure that the forms remains square.

4. 

   Builders hand level for form work.

   Level the forms using a builder's hand level and nail them to the vertical stakes with 8-penny nails. Next frame a 3-sided form shorter than the first by the width of a tread. Place this on top of the base form, and carefully level and nail it at each stake.

5. 

   Concrete forms.

   Repeat the process with a third frame, again shorter than the second by the width of a tread. This last form will make the landing in a 3-step set of stairs.

6. 

   Finishing concrete.

   Nail 1 by 3 boards vertically with 8-penny nails as needed to reinforce the forms. Next prepare four 2-by 4-inch pointed stakes and drive them firmly into the soil against the form. Nail with 16-penny duplex nails for additional strength.

7. 

   Batter boards and twine to line forms.

   Using twine to keep the form straight, drive 1 by 3-inch 45-degree "kicker" stakes into the ground and brace them into the forms. Use 45-degree temporary braces inside the forms to keep them in line awaiting the concrete pour.

8. 

   Cutting rebar.

   Prepare two bars of 1/2-inch steel rebar formed in a rectangle to fit in the stair footings. Hang the steel from the form boards at the center of the footing top and bottom. Also, form a rebar rectangle to hang mid height on the top form board. Connect the rebar rectangles with three straight steel rebar pieces.

9. 

   Premix or site mix concrete can be used.

   Pour concrete into the forms starting at the open end against the house. Rod off the excess concrete and tamp the surface leaving the moist concrete slightly higher in the center than the form level. The concrete should be allowed to cure until the forms can be removed without damaging the "green" concrete. At this point an experienced finisher should complete the finish on all exposed surfaces.

Tips & Warnings

• A hand grinder is an easy way to cut rebar. Stair treads can be wider, but not narrower than 10 inches. If you have the room, it's nice to stretch the treads to 2 or 3 feet for effect.

• Take care with the concrete mix to avoid excess water. The concrete should "slump" but not flow, in order to cure properly in the forms. Make sure that all treads as equal, as unequal treads can be real "trippers," and are in violation of most codes.

References

• American Concrete Association

Resources

• FHA Minimum Property Standard