I declared dislike for concrete pavement. So what was I to do with the concrete pavement that already existed, such as the parkway path? Rip it up and replace it with something that has a better longevity and is more artistic?
That was a very tempting thought, but it came up against my practical inclinations. The best time to replace things is when they start falling apart. The existing parkway path was not at that point – yet.
That left me with the question about what to do with this monolithic gray mass.
How about the “putting lipstick on a pig” approach? I could frame the concrete path with a row of salvaged, old Chicago street pavers, transforming it from monolithic to something the eye can manage.
Unlike the parkway path with the pavers, the monolithic concrete slab did not need a structural constraint around the edges. It was both, constraint and pavement. That allowed me to place the framing pavers on a simple gravel base, instead of a concrete bed.
The pavers will get almost no traffic, and with that almost no stress. People prefer to walk along the centerline of the path, i.e. on the concrete slab. Rarely will anyone need to step on the pavers.
My last thought on this subject went toward deconstruction. At one point, I would like to replace the concrete slab. Removing the paver edge and concrete slab will be a easier with the pavers just sitting on gravel.
I had to excavate our parkway rain garden to a ponding depth of six inches. It was a very simple task, except for the treasure hunting aspect of our urban soils.
I didn’t want to start with the excavation until I had a barrier around the rain garden. Although the drop into the bottom of the rain garden wouldn’t be more than nine inches, I still was worried someone could fall into it. Now that I had a fence surrounding the parkway rain garden, with the exception of the fence panels, I was ready to start digging.
My goal was to plant my rain garden plants into a medium that resembles top soil. That was not an unrealistic goal, considering that the top layer in the parkway was a fairly good quality topsoil. But what was lurking underneath made things a lot more interesting. In a way, it was a little bit like archeological discovery that told a story corroborated by the surrounding landscape.
The parkway rain garden will stretch across two city lots. To the east is a vacant lot. It once had a building on it, but that was torn down. I am not quite sure when but it must have been sometime after the 60s. To the west is the lot on which sits our house, which was built in 1902. It think it is fair to assume to most buildings on our block were built around that time, including the house that once stood proudly on the vacant lot.
In my preparations for excavating I noticed that the parkway at the vacant lot had topsoil layer of about four inches, followed by a good six to eight inches of soil mixed with rubble. Below that was a decent layer of dark colored subsoil.
The parkway section in front of our house did not have the rubble layer. The topsoil slowly transitioned into an equally dark colored subsoil. It comes close to an uncontaminated or clean soil profile.
That may speak to the construction methods around 1900. I could assume that the crews cleaned up the site once they were done with the building, but I seriously doubt that. I think it is more likely that back in the day, builders didn’t use the equipment we have available today, and thus didn’t recklessly ruin the soils the way we do today.
The rubble layer at the vacant lot, on the other hand, most likely dates back to the tear down of the building.
Overall and given our urban environment we are blessed with decent soils, which we could maintain as long as I could find a way to address the rubble layer.
My method was as follows: I started by excavating and saving the topsoil, which is now in a stock pile in the vacant lot. Next I excavated the rubble layer and hauled it off site. Once I started excavating to the west, I relocated part of that topsoil to the east, until I had met my ponding depth of six inches.
A Tom Sawyer moment
When I started excavating, it was still summer break and the kids on the block were stifled by boredom, including four brothers who live two houses down. First they found some distraction by watching me dig. That lasted about ten minutes. Then they riddled me with questions. That lasted a little longer. Then they argued among each other who would do the best job digging. And finally they were begging me to help.
I got my spare shovel and let them have a try. To my surprise, the youngest and smallest of the four was not only the most skillful, but also the most relentless. He almost kept up with me. And once the last of his brothers had his turn, he wanted right back into the game – and I was grateful for the help!
I get a kick out of reusing and repurposing salvaged materials, whether it is in the house, the yard, or in this case, our parkway landscape.
We have two gates to our property: the main gate leading up to the front door and the side gate leading into the side yard. It made sense to provide a path crossing through the parkway landscape at each gate.
We already had a path crossing at the main gate, although it needed some additional work. More about that later. But there was no formal path crossing at the side gate. While laying out and installing the parkway knee fence, I made sure to provide a gap for a path to connect to the street.
A material question
No, I will not use poured concrete. Boring! It can be the default pavement choice around the country all day long. That doesn’t mean I have to like it or bow to it. And on top of that, it’s not even that practical. It tends to crack over time. And repairing it always looks like – well – it has been repaired.
I had some beautiful salvaged graystone and clay pavers in my yard that were perfect to craft a path crossing through the parkway. I knew I could repurpose the graystone into a curb flanking the path left and right. The clay pavers are modular, which makes for a much higher quality pavement if installed correctly. It doesn’t crack, because it has cracks already built into it – the joints between each paver. And it is easy to repair, because – well – it’s modular.
Building it up from the base
I put a decent eight inch base down using recycled aggregate and made sure to compact it thoroughly. Integrated into the base were two two-inch PVC pipes. They will hydraulically connect the parkway rain garden to the east and west of the path.
I also had the city water vault and shut-off valve in the path of the parkway path. (Probably not perfect, perhaps even painful, to pitch this many p’s in one phrase. But once I plunge into a pattern of packing p’s I am past picky.)
I had to align the pavement elevation with the valve and vault. The elevation of the valve was set and I couldn’t change it. But I could adjust the elevation of the vault base and I did, so that it matched the path slope determined by the valve.
With the pavement elevations set, I put a concrete base down and set the curb using my salvaged graystone. Most paver installations need a structural constraint around the edges, or otherwise the pavers start migrating over time. That is particularly true if they are adjacent to a downward slope like my planned rain garden – even if it’s only a four or six inch drop. So the curb on a concrete base was a must.
After the concrete had cured for a day, I could bring the gravel base up to the right elevation and start to screed the sand bed (setting layer) for the pavers. Then I set the clay pavers right into the sand bed. There was some fitting involved along the edges and around the vault. To fill the smaller gaps I switched from clay pavers to graystone scraps.
To finish the job, I needed to fill in the paver joints with sand, make sure the pavers sat firmly in the sand bed, and assure the paver surface was even. The sand can be broomed and washed into the joints. To set the pavers firmly I used a two by four and a hammer and whacked the pavers into the sand bed. That process also allowed me to get to an even surface.
The fence posts were in place, which allowed us to install the bottom and top rails. Because the bottom rail will sit right at the pavement edge, we had to excavate a little more along the sidewalk. The curb side edge was already excavated from our paver edge installation.
We cut the top and bottom two by four rails to length and attached them with structural connectors to the posts. At the same time, we pre-drilled the two by two rails that will hold the rebar and attached them to the back of the two by four rails.
I chose to only install the fence rails around the perimeter, because I still have to excavate for the rain garden. That will be easier to do if I can move up and down the parkway and in and out at the path crossings.
My nicely aligned posts alone won’t make a fence. I had to make up my mind about the fence panels, so let’s get back to basics for a minute:
Using metal in the fence panels is a risky proposition as it might get snatched by scavengers overnight. Instead, we opted to use pressure treated lumber. We installed the four by four fence posts, and I planned to use two by fours for the fence rails.
The rails alone won’t suffice. I needed a somewhat solid fence panel to keep trash from blowing into the rain garden vegetation. I considered a whole gamut of ideas, but let me make this short.
The concept of woven fence panels persisted. Woven, like wicker furniture or an old fashioned willow basket. This would add a level of surprise or contrast, as it would not be expected in an urban context. Yet I’d have to make it sufficiently robust to persist through the urban pressures.
And this is where I had to rely on metal after all: half inch or number four rebar. While I still wanted to use a wooden material like willow for the horizontal weft, the vertical warp had to be rebar.
But how could I prevent the rebar from growing legs at night? By slipping it through a pre-drilled top rail and into a three quarter inch hole in the bottom rail. A handrail attached to the top rail would lock the rebar in place.
One problem was solved, but another one was created. I ended up with two very different fences in close proximity: the woven panel knee fence around the parkway and our typical Chicago style black metal yard fence.
Patchworks of different style can generate something visually stimulating. But in this case, creating a connection between these two different enclosures and as such weaving the parkway landscape into the remaining landscape on our property would be more inviting. Rather than passing a semi-public landscape on the parkway side and a private landscape behind the property fence, we would prefer to invite observers to pass through an extension of our private landscape, which reaches all the way to the curb.
How could I begin to weave those two landscape together? Literally by weaving. I could use the same willow material that I plan on using in the knee fence panels, and weave a solid panel into the bottom our our yard fence. The added benefit would be that even more blowing trash close to the ground will be blocked by semi-solid paneling and kept out of our plantings.