I built a walkway from my patio out to a gazebo in the center of the layout. They are about forty feet apart with a two foot difference in elevation. I used steps to gain the necessary height. The path crosses both the inner and outer loop tracks so a couple of railroad crossings were required. This post documents the construction and provides a few tips for the benefit of anyone contemplating similar concrete projects.
I didn’t need enough concrete to justify ordering a truck of ready-mix, so I used 80 pound bags of Quikrete® concrete mix. It required twenty-three bags for the steps and forty-five bags for the walkway. For DIY concrete projects like this, I use my reliable old Harbor Freight mixer, purchased over 20 years ago. Although I paid considerably less for it back then, you can still get this same model today for under $200. I generally mix two or three bags at a time. Here is a shot of me dumping an 80 pound bag into the mixer.
It really helps if you have someone else to work the concrete into the forms while you do the mixing and dumping. You can do it by yourself if you have to, but it goes a lot faster with a helper. Here is a shot of Mary using a 2” x 4” board to screed the mix level with the top of the forms.
I began by installing a drainage system at the intended location. It connects to an existing French drain that runs along the perimeter wall of the layout. For details on the existing drain, see my post at: link to post
Here is the new drain extension that runs under the steps and walkway:
After the drainage system was in place I began contouring the area for the steps. I cut away part of the thyme covered slope and brought in enough additional fill dirt to build-up the area for the steps and walkway. I used a hand tamper to thoroughly compact the fill after every three inch layer was added. I carved out the step locations keeping the level of the soil base approximately six inches below the desired final grade.
Steps are made up of the tread, which is the horizontal part you step on, and the riser, which is the vertical part you trip on. It’s important to have the right ratio of tread to riser to make going up and down safe and easy. As a general rule, the smaller the riser, the bigger the tread. For the most part you should choose what is comfortable for you. Once you find a ratio you think will be comfortable, plug it in and tweak it until it fits this formula: Step tread + (2 × step riser) = 26 or 27 inches. The following figure illustrates recommended minimum tread and maximum riser dimensions. Note that the risers should not vary by more than ⅜”.
I made the riser = 5½” and the tread = 16”. There are a couple of exceptions to the tread lengths. The bottom step uses a double length tread because it includes a track crossing. I wanted to be able to comfortably cross the track without negotiating a step at the same time. The other steps are curved and the 16” dimension is the minimum tread depth measured on the inside of the curve. The tread at the outside of the curve is 23” deep.
I pre-built a 6-foot long roadbed section for the crossing using ¾” x 1 ½” PVC lumber. Llagas Creek flex track will be attached to the roadbed with #2 x ½” screws. The gray 1” PVC conduit is a spare just in case I ever need it. More about this later.
I built forms for the bottom step with 4” wide Masonite bender board, tamped in a layer of sand, and placed sections of welded wire reinforcement (WWR) in the forms. The forms for the bottom step are only 4” high because the mortar and flagstone veneer will increase the first step to the desired 5½” height. Here is the first step ready for concrete:
I filled the form with concrete leaving a rough-troweled surface. I pressed the PVC roadbed into the wet concrete so that the rail tops would be 1½” above the surface of the concrete. After the concrete firmed up, I removed the roadbed section, cleaned off the concrete residue, and painted the PVC flat brown.
Here is how the step looked after I pulled the PVC roadbed from the concrete. I’ll stick it back in after I apply the flagstone veneer.
I built forms for the remaining steps from 2” x 6” boards (which are 5½” high.) I placed a layer of sand in the forms, compacted it, and placed sections of WWR. Just remember when you make concrete forms, they don’t have to be pretty – just accurate and strong enough to hold the concrete in place until it sets.
I filled the forms with concrete leaving a rough-troweled surface.
I used the old modeler’s tricks of forced perspective and gentle curves to make the steps appear more attractive. The bottom step is nearly six feet wide at the edge of the patio. It narrows to about five feet where the track crosses and shrinks to about four feet at the base of the second step. Successive steps are each slightly narrower and the top step is only 42” wide.
From top of the steps over to the gazebo, the walkway is 42” wide. I flared out the width at the end to match the corners of the gazebo. The final step, from the walkway up into the gazebo, is 5½”, just like all the others. Rather than using a straight line, I routed the walkway in a spiral curve to make it appear longer. The walkway forms are ¼” Masonite bender board. I placed a two inch layer of sand in the bottom of the form and tamped it firm. Here is the walkway before the sand was tamped into the forms and before the WWR and rebar were added:
The inner loop track crosses the walkway on a diagonal about halfway between the steps and the gazebo. It was made using the same method as described for the outer loop crossing at the bottom step. The black spirit level sitting on top of the PVC roadbed is six feet long.
I placed WWR in the forms and used spacers to hold it approximately in the center of the four inch thick concrete. I also used lengths of ⅜” diameter steel reinforcement (#3 rebar) to further reinforce the concrete at the crossings and joint locations. The joints are spaced at approximate six foot intervals along the walkway. I make the joints by slicing the wet concrete about an inch deep with the point of a trowel. You can’t keep a long concrete walkway from cracking, but you can control where it cracks and keep the sections in proper alignment.
Rebar is also a handy way to tie together sections of concrete poured at different times. Just make a temporary end form at the point you want to quit for the day. Drill ⅝” diameter holes in the end form about midway between top and bottom. Insert 2-foot lengths of ⅜” diameter rebar into the holes about half way into the form. Pour concrete up to the end form. After it sets, remove the end form by pulling it out over the exposed sections of rebar. When you are ready to pour the next section, just wet the previous section and continue pouring concrete.
Remember the spare 1” conduit under the first step I showed you earlier? Whenever I build a permanent or semi-permanent walkway, I always try to add a couple of PVC pipes and/or conduits underneath for future use in running electrical, lighting, or irrigation circuits. Cap both ends to keep them from clogging with dirt. If you never need them, you’re only out a few bucks. If you do need them, they’re priceless. Don’t rely on your memory to find them later; take a few photos and file them away for future reference. Here is a spare 1” PVC electrical conduit and a spare ¾” Schedule 40 PVC water pipe running under the walkway near the gazebo.
I used sixteen 60 pound bags of Quikrete® mortar mix to apply approximately 150 square feet of flagstone veneer. The field is Tennessee bluestone and the borders are Colorado red sandstone. I applied the borders first, and then came back and applied the field, starting at the gazebo and working my way down to the patio. Here is a shot of the veneer application nearing completion.
After the mortar cured for a few days, I pressure washed the stone to remove any traces of mortar residue from the surface. A few days later, after the stone was thoroughly dry, I applied a solvent based sealer to the surface.
At both crossings, I left a 4” wide gap in the flagstone veneer. The flagstone surface is level with the rail tops. I filled around the track with granite chips (poultry grit.) The section of track can be easily replaced if damaged. The following four photos show how the crossing is constructed.
Near the top of the steps, I needed a footbridge to cross the stream at this location to access a secluded seating area:
I built the bridge with rough-cut cedar 2” x 6” lumber. I used a band saw to cut low arch profiles into the tops and bottoms of the three 4-foot long stringers. The floor planks are 32” wide and overhang the outer stringers by 2” on each side. The base plates on either end of the bridge under the stringers are pieces of 2” x 6” identical to the floor planks. These will set directly on concrete foundations. I painted the wood pieces with Thompson’s Water Seal® Woodland Cedar opaque stain and assembled them with 3” deck screws. Here is the bridge setting on a pair of saw horses after assembly:
After turning off the pump for the stream, I removed the rocks, pulled back the rubber liner, and excavated holes for the foundations on either side of the stream bank. I built a single frame with a form above each hole. This ensured that the two foundations would be level and parallel with each other.
The foundations required four 80 pound bags of concrete mix. After filling the forms, I inserted galvanized foundation anchor bolts.
After the concrete set I removed the forms, repositioned the rubber liner, replaced the rocks, and turned on the pump. I drilled holes in the base plates of the bridge to match the position of the anchor bolts and attached the bridge to the foundation. I filled-in the approaches on either side of the bridge and dry-laid stepping stones on the fill. Here is what it looked like as I was fitting the stepping stones.
The small seating area is constructed with interlocking concrete pavers dry-laid on a sand bed. I will place a hidden edging around the perimeter to hold the pavers in place and keep the sand from washing out from under them. Installing pavers or flagstone like this is much faster and less expensive than on concrete. Of course, it is not nearly as durable and will eventually need maintenance. However, it can be relatively easily removed or modified at a later date, whereas stone laid on concrete is “cast in concrete.” Keep that in mind as you plan your concrete projects.
Hope this post has given you a few ideas for using concrete to build walkways, steps, and crossings on your own layout. But before I close, here are a few common sense precautions when using concrete:
- Protect your eyes. Eyes are particularly vulnerable to blowing cement dust and concrete splatters from the mixer.
- Protect your back. All materials used to make concrete – Portland cement, coarse aggregate, sand, and water – are quite heavy even in small quantities. 80 pound bags of concrete mix weigh, duh, 80 pounds each.
- Protect your skin. Prolonged contact between fresh concrete and skin surfaces, eyes, and clothing may result in skin irritations and chemical burns that can be quite severe, including third-degree burns. Portland cement (the bonding agent in concrete) is hygroscopic – it absorbs water. It will draw water away from any material it contacts – including skin.
- Protect your plants and fish. Fresh concrete is extremely alkaline and will adversely affect acid-loving plants and raise pH levels in nearby ponds and streams. Protect your groundcovers and small plants with tarps. Wash off accumulated dust from leaves. Keep run-off away from ponds and streams.
All things considered, concrete is easy to work with, versatile, durable, and economical. It is one of the safest building materials known. Don’t be afraid to use concrete. After all, the Romans built structures with it that are still standing. Just think how impressed visitors to your layout will be two thousand years from now.
Bob
