Pouring a Concrete Walkway 1
Intro and Materials
Millions of people from all walks of life are re-discovering the joy that comes from working on and maintaining their own homes. With the rising cost of contract labor and real estate, now more than ever is the time to maintain and improve what you already own. It can sometimes be a challenge figuring out which projects are ones that you can tackle on your own over a weekend and which ones are better left to a professional. The ideal situation of course, is made up of projects that you can do on your own, simply because of expense.
With the variety and availability of professional products that are on the market now from most retailers, pouring a concrete walkway is definitely on the list of things that you can do yourself. If you don't mind breaking a sweat and getting a little dirty, the technical aspects of this job are quickly learned, and the step by step instructions are not difficult to follow. This is a project that you can tackle with confidence and one that you can finish with pride.
When I was a kid, it appeared that I was going to make a career out of starting projects that I could not finish. Looking back, I can attribute most of those failures to a lack of preparation. I perpetually drove my father nuts because he is a detail oriented person who plans every facet of a project down to the last penny nail before he even thinks about beginning. I was more prone to fly by the seat of my pants and if things didn't go well, I'd adjust on the run or more often than not, just quit.
That being said, this is a project that does require a little planning. Be like my dad. Take the time to draw a picture of exactly what you want to do. Write down the steps that you are going to follow and then stick to it.
One of the main reasons you want to do this is so you have an accurate shopping list, and so you don't spend half your time running back and forth to the home improvement store to get supplies. Nothing adds time, expense and frustration to a project more than not being adequately prepared. As you sit down to draw your picture and prepare your list, here are some things that you definitely want to make sure are on it.
Lumber: 1x4 and 2x4. You will need the 1x4 to build the form that the concrete will be poured into. Depending on the size of your project, make sure you have enough to go all the way around the outside of your proposed walkway. The 2x4 will be used to screed the wet concrete. One 2 x 4 x 8 should be sufficient.
Screws: The screw will be used to attach the 1x4 to the stakes. Make sure you get screws that require a tip that you have for your screw gun.
Wire mesh: This usually comes in rolls. It is big, and dirty and a pain, but will add a lot of strength to your walkway. Don't get lazy and skip this step; it's just not worth it.
Concrete: We'll discuss this in greater detail later on, but for now, just get basic concrete mix.
Mixing Tub/Wheelbarrow: I always use a wheelbarrow because I don't have to shovel the concrete twice that way. If you want to save some expense and get a cheap mixing tub it will work fine, you just have to handle the wet concrete one more time when you shovel it out of the tub and into the pour.
Trowels: Pointing, edging and a float. The trowels and floats come in a variety of qualities. If you are a do-it-yourselfer who isn't going to use them everyday, I would suggest going middle of the road on price. You don't need the very best since you don't use it daily, but you also get what you pay for and the lower quality tools may directly affect the finished product.
Stiff Broom: This will be used to add the no slip texture to your walkway.
Rake: You will need a rake to level the dirt or gravel surface underneath your walkway before you begin pouring.
String 500': The string will be used to lay out your walkway and will be very valuable as you try to ensure that your form is square.
Wooden Stakes: These will be driven into the ground and used to fasten the 1x4 that makes up the form.
Hand tamper: Also used to ensure that the ground is flat and level underneath the pour.
Sledge hammer: Used to drive the stakes for the form.
Pouring a Concrete Walkway 2
Preparing the Area
Now that you have all your materials gathered and you have a plan of what you are going to do, it's time to begin the actual labor. Before you mix any concrete, it is important to make sure that the area is ready to receive it. One of the biggest factors in determining the longevity of your sidewalk is how well you prepared the surface underneath it.
1. Use your shovel to dig the walkway area to a depth of 4". Make sure that the ground is fairly level and that there are no large pieces of debris.
2. Using the rake and the hand tamper, make sure that the surface is flat and level. By ensuring that the surface is level, you can be sure that your sidewalk is of a uniform depth.
3. When you are satisfied that the surface is flat and firm, roll the wire mesh over the entire area to be poured. This will most likely require some cutting and repositioning of the mesh. If you have some angles or turn a corner with your walkway, then you may have some places where the mesh overlaps. Don't worry, this is fine.
Building the Form
The form is what will hold the wet concrete into the desired shape while it cures. Some contractors will use a system of interlocking steel beams to create walkways. For the homeowner, however, it is quite feasible and fairly simple to build your own from wood.
1. Using the sledge hammer, drive a stake into each corner of the area that is to be poured. Tie the string to one stake, and then run it from stake to stake until you have created a string outline of your walkway.
2. Measure across the string at both ends of the walkway and in the center to make sure that your stakes are properly placed. This step is important because it will ensure that your walkway is square. This doesn't have any effect on the strength or functionality of the pour, but it will make a big difference in the way the final product looks aesthetically.
3. After you are comfortable with the layout of the area, continue to drive stakes into the ground every 6" to 8" making sure they are lined up evenly with the string. Once all the stakes are in, you can begin to screw the 1x4 boards onto the inside surface of the stakes. This creates the box that you will actually pour the mixed concrete into.
4. Take one final measurement of the completed box to ensure it is square. Adjustments are very difficult to make if you discover this problem after you have already started to pour.
As you can see, building a concrete form is fairly simple. Just keep in mind while you are building it that at a point in the future, you are going to need to run a 2x4 over the top of the entire form to screed out excess water. This will be much easier to do if you make sure that the stakes are driven about 1" below the top of the 1x4 board that makes up the wall of the form. It is very difficult to screed when there is a stake sticking up every 8 inches over the top of the form, and it's not something that you can go back and fix after the fact. Once you've got concrete inside the form, you are pretty much done making adjustments
Pouring a Concrete Walkway 3
Mixing and Pouring
There are traditionalists out there who, when you ask for advice, insist that you must mix your concrete from scratch. You will see them slaving away over a mixer with a pile of sand, a pile of portland, and a pile of gravel. They will work tirelessly trying to achieve the perfect oatmeal like consistency. You, however, will already be done. There are times, places and projects that require a custom mix. The basic walkway that you are constructing is not one of those.
When you go to your local home improvement store you will most likely be met with a large number of choices. There are quite a few pre-mixed masonry products on the market and most are packaged in heavy paper bags that look quite a bit alike. You are looking for a basic concrete mix - a "just-add-water" formula that already has portland cement, sand, and gravel in it. You really do just have to add water.
Remember, you do not want mason mix, mortar mix, sand mix or a re-surfacing mix. There are some basic concrete mixes available that are high strength mixes. It will not hurt if you use these, but they are designed for floors that take a lot of heavy abuse, like the floor of a truck garage or a warehouse. You may also find some quick drying mixes. If this is your first time working with concrete, I would recommend that you stay away from this until you are comfortable with how long it will take you to screed and float your surface. If you use the quick dry formula and it starts to set up before you are ready, then you've got big problems.
Determining how much product you need to buy requires a little bit of math, and the number of bags that you will buy depends on how big the bags are. Most manufacturers print a chart on the outside of the bag that will allow you to figure how much you will need. You need to know how many square feet the area of your pour is and then use the chart to figure that area by 4" deep. A little hint is to take a calculator to the store with you. It will come in handy when you are standing in the aisle trying to figure square footage and cubic feet in your head.
Once you get the product home, you will need something to mix the concrete in. You can buy a plastic mixing tub that will work quite well. I prefer to use a wheelbarrow because I can dump the wet concrete out of it instead of having to shovel it out like I would if I used a mixing tub.
When you are finally ready to start mixing, there will be a ratio printed somewhere on the bag that tells you how much water to use. This is difficult to measure when you are doing large scale projects. I would recommend mixing one batch up slowly. Keep adding water a little at a time until the concrete mix reaches a nice oatmeal like consistency and then pour it. The rest you will be able to do by sight and should go faster.
Depending on the budget for your project, you can also look into renting a portable mixer. This has a drum on it that spins, much like a smaller version of the drum on a cement truck. You pour the dry bag into the drum, add water, plug it in and watch the drum do some of the manual labor for you. Typically the drum is emptied into a wheelbarrow and you can wheel it and dump it exactly where you want. Keep adding concrete to the form until it comes right up level with the top. You want to fill it up so it just begins to overflow. This will ensure that you don't have any low spots once you begin to screed the surface
Pouring a Concrete Walkway 4
Screeding and Finishing
At this point you now have a wooden box filled with wet concrete that looks nothing like a walkway. Relax. Getting the finish product that you desire is just a few steps away.
First, use the extra 2x4 to begin leveling the concrete with the top of the form. This process is called screeding. Rest the 2x4 on the top rails of the form, and with one person on each side, quickly move the 2x4 back and forth in short strokes, pushing the wet concrete from one end to the other. This will accomplish several things. It will level the surface by pushing any extra product that you have over the edge of the form. Second, it will begin to push up the excess water that is in your mix. This is vital if the concrete is to cure correctly. Make your way across the entire surface of your walkway, wait a few minutes, and then do it again. The excess concrete that spills over the edge can be used to fill in any low spots that you may find.
After screeding the surface twice, or maybe even three times if you still have low spots, it's time to get your float and begin smoothing the surface. The float is designed to do just what its name implies. You do not want to apply a great deal of pressure, as this will create an uneven surface. Instead, you will find that as you pass the float over the surface, it will actually pull water to the top and the water will create a nice smooth finish. It will take a little touch, but after a few minutes of practice you will be floating like an old pro.
Once the concrete begins to stiffen to the point where you can put your finger in it, and the hole doesn't close back in on itself, then it's time to do three things. First, fix the hole that you just made with your finger by going over the surface with the float one more time. You will find that, the more the concrete stiffens, the nicer the surface will remain after you float it.
Second, it's time to mess up your fresh newly floated surface if you don't want to fall on your face the first time it rains. Smooth, wet concrete can be extremely slippery. Take the stiff broom and drag in slowly across the stiff, but still wet surface. Don't push, just let the weight of the broom do the work. It will create a nice textured surface that will be slip resistant. The carrier of your homeowner's insurance policy will love you for doing this.
Third, take your edging trowel and begin to go along the edges, creating a nice looking finished product. You can also measure off 36" to 42" sections and use the trowel to form breaks in the walkway. Not only does this look nice, but it creates a natural water run off and helps prevent ice problems in the winter.
After a few hours, use the pointing trowel to separate the pour from the forms. It's much like using a spatula to separate the edges of a cake from the pan. Gently insert the sharp end of the trowel's nose between the concrete and the form, taking care not to mess up your edge. Once it's been separated, you can begin removing the screws and taking up the boards that make up the form. It is possible, and sometimes recommended just so people don't walk on your still wet walkway, to leave the forms in place for a day. You still need to use the pointing trowel to make sure it's not sticking to the form while it's wet, but you can then leave the form in place as it serves to announce to folks that the sidewalk may not be done yet.
Pouring a Concrete Walkway 5
Clean Up and Sealing
The key to doing a concrete project without ruining your tools is to clean up as you go. Do not stack dirty tools in a pile and then plan on cleaning them up at the end. Chances are you will have a big pile of dirty tools that are stuck together. Keep a garden hose nearby so that you can spray down each tool as soon as you are done with it and set it aside to dry.
There may be some excess concrete that ends up drying outside the form. If you shovel it up, it makes great fill around foundations or if you ever have any posts to sink. If not, it can be disposed of at the landfill. The 1x4 boards that you used to create the form are certainly useable. While they probably aren't going be used for finish work, they will do just fine for any structural work. The exposure to the wet concrete will not harm them at all.
I would always recommend that you select a weekend for this project when the weather forecast does not include rain. If some unexpected showers turn up in the first 24 hours or so after you complete the project, make a quick trip to the store and get some heavy plastic sheeting. Just lay it over top of the concrete. It's OK if the surface get a little wet; you just want to prevent puddling directly on the concrete.
There are a number of products available to seal your new concrete walkway. One of the biggest mistakes people make is using one of these products right away. This has a negative effect on how well your concrete will cure. Even though it may look hard an dry on the outside, it can take a long time - even weeks or months - for concrete to cure all the way through. The sealer is design to keep your concrete from absorbing water, but if it is designed to keep water out, then it will also keep water in. By sealing too soon, you can actually trap moisture inside the pour and it may never cure properly. When it freezes in winter then, this moisture will expand and your new sidewalk will crack. It is generally recommended that you wait until the second season to seal a new patch of concrete.
With that said, grab a piece of paper. Draw a picture and make a list. With the right preparation, this is a project that you can do in a day and one that will add value to the exterior of your home immediately.