The first step in increasing your home’s curb appeal may be to fix the first steps leading to your property. If they’re bad, so may become the mood of prospective buyers even before they step foot in your lovely home.
Here are 11 steps to take when your concrete stairs are crumbling, as mine were:
1. Contact a local building official. It’s probably OK to rebuild the steps to the same dimensions, but it’s always wise to check with local officials about whether permits are required.
2. Rent a jackhammer. If you’re removing all of the existing concrete in your stair system, go at it. But in my case, only the steps needed to be removed. So I used an angle grinder (photo 1) to cut around the edges of the steps to protect the sidewalk, side walls and landing step from the jackhammer’s vibrations.
You can try breaking up the old concrete with a sledgehammer, but it’s typically tough going. Another way that’s fun (but probably not for this small job) is to use expansive cracking agents (such as Bristar and Dexpan). These chemical powders, which are not usually sold in small quantities, are mixed with water and poured into 1 ½- to 2-in.-dia. holes drilled in the concrete. Over the next 24 hours, the agent expands with a force of about 18,000 pounds per square inch, cracking the concrete.
Renting a 90-pound jackhammer makes the job easier (photo 2). It’s noisy and chips fly, so wear ear and eye protection. The tool itself is heavy to lift repeatedly after breaking up the concrete into small chunks, so use your legs to lift and keep your back straight. Save the concrete chunks for fill when you rebuild the stairs.
3. Build forms. The side walls were sound, so all that was needed was scrap lumber ripped to the height of the riser, in this case 4-1/2 in. I cut the riser form just a fraction longer than the distance between the two side walls (52-1/4-in.); this made for a snug, secure fit when I tapped the form into place with a hammer. To prevent the riser forms from deforming under pressure from the poured mix, I made braces from scrap lumber and wedged them between the form and cinder blocks for extra support (photo 3).
Build the forms so that the tread slopes slightly away from the house. A tread slope of between 1/8 in. per foot and ¼ in. per foot is good. Also follow these tips:
• When cutting the riser form, bevel the bottom edge so you can better pack the mix into the juncture between the tread of the bottom step and the riser of the top step.
• Use screws rather than nails when building forms. Backing out screws is easier than pulling out nails.
• Use a spray lubricant on the side of the forms that will face the wet mix. This makes it easier to remove the forms when the concrete is set.
4. Install isolation boards. Use adhesive to fix ½-in. asphalt-impregnated isolation board against the existing concrete. The isolation board (available at home centers) separates the new concrete from the old. New concrete can react differently to frost and heat, which could lead to cracking caused by one concrete’s moving against the other.
5. Tamp, rock and roll. Tamp down a base of gravel, and cover with the clean rock fill created when you broke up the original steps. This conserves concrete costs and mixing time. Now you are ready to roll with mixing cement.
Tip: Keep the rock fill several inches away from the exterior surface to avoid weakening the concrete.
6. Mix concrete. The number of bags of the standard concrete mix needed depends on the number of square feet of your project; buy according to the specifications on the bag. When in doubt, buy many more bags than you think you’ll need. Unused bags can usually be returned, and you don’t want to run out of mix before the project is done.
Add water slowly to the mix. The wet material should flow readily but not pour. A mix that’s too wet makes weak concrete.
It’s good, but not necessary, to mix a bonding agent into the water before mixing water and concrete. The bonding agent strengthens the concrete.
Mixing with a hoe and wheelbarrow is a good workout. It’s also a slow process. You may want to rent a portable mixer (photo 4), but don’t expect to just turn on the machine and have instant mix. Some of the concrete at the bottom of the bucket may not get mixed in, which means you’ll need to stop the machine and mix by hand. All in all, you may not save much time compared with mixing in a wheelbarrow.
7. Shovel and pack the mix. Fill to a little above the height of the forms. Stop shoveling intermittently and use a stick of scrap lumber to pack the mix into the corners, around the rocks and especially into the base of the riser forms. The more you pack, the more air pockets you’ll remove.
8. Screed the surface. Use a straight 2x4 to screed the surface, working the board back and forth along the top of the form. However, screeding has limited value here, as the steps are below ground level, so make do with a hand float and a trowel. Making repeated passes along the width of the stairs with the float’s leading edge angled up (photo 5) helps continue the mixing of ingredients and levels the surface.
9. Finish the edges. With the leading edge up, run an edging trowel between the forms and the edges of the stairs (photo 6). This rounds the edges and makes them less susceptible to chipping and cracking.
10. Brush the surface. A smooth surface can be dangerous when wet, so rough up the stairs by brushing the wet surface with a broom (photo 7).
11. Let the concrete cure. Lightly spray the surface with water and then cover with plastic. Concrete crystals will keep forming as long as water is present. The first week, concrete will cure to about 80 percent of its final strength, so spray and cover repeatedly. When the week is up, remove the plastic and forms, and begin using the stairs. After a month or so, the concrete will be at a strength of 90 percent or higher.