A client in Waterloo reached out to us to discuss their backyard renovation project that they had in mind. This involved creating an area for them to set a table and chairs and enjoy their backyard in the evenings and on the weekends. The problem was that their backyard sloped aggressively so we presented them the option of creating a raised patio to account for this slope. We also suggested to raise the wall about 18 inches in height above the pavers to create a sitting wall for them. They loved the idea and we rolled with it!
The client had a product in mind that is a concrete paver that looks like natural flagstone and is irregular in shape. So for the entrances into the patio from either side we decided to follow the irregular edge of the concrete paver. However one side required a four foot step up so we ended up cutting this part straight in order to get the step in there. We also needed two steps up to the porch to account for a 21 inch drop down to our patio. With the wall product we chose for the seat wall, we built the steps along with two 4 foot caps on top of each step to provide our client with two giant 8 foot steps.
We begin this project by excavating the backyard to a depth of 12 inches. This gives us room for 8 inches of base material, 1 inch of bedding layer to level our pavers on top of, and the height of the pavers themselves. In addition to this excavation, we need to dig an additional 6 inches deeper for the area where the seat wall would be installed as we need to bury a minimum of 6 inches of our wall below the final grade of the pavers and garden bed beyond the seat wall.
Once we have excavated our project, we then compact our subsoil and lay a non-woven geotextile throughout our entire base. This geotextile separates our base from our subsoil to ensure there is no movement between the two. We can then begin to install our base material. In this scenario we opted for a dense graded base which consists of Granular A or 3/4″ angular crushed stone down to fines. This gets laid on top of our non-woven geotextile and is compacted firm with moisture added to it. Once we have our 8 inch base in our trench for the wall, we can then start to level our wall blocks for the seat wall.
Each block is leveled side to side and front to back with one another. We use the natural curve of the wall block as each unit is tapered and can be combined to create various radius choices. The initial layer of any wall is the most time consuming. All of the additional layers, especially for a seat wall, does not take a lot of time as it involves stacking blocks one on top of the other while ensuring that there is a stagger on the wall. There should never be two blocks stacked directly on top of one another. The exception to this is with this wall block we have two different heights that are being combined and we can use two of the smaller units to create one of the taller units. We also tie some geogrid into our wall and extend it into our paver patio. This stabilizes our base material and prevents movement which adds pressure to our wall.
Once our wall is completed, we then cut our natural stone caps for the curve around the seat wall and lay the remainder of the caps along the straight runs. We added hardscape lighting along the seat wall which beam downwards onto the patio for them to enjoy in the evenings. The caps are then adhered using a hardscape adhesive to finalize the seat wall.
Our block steps are installed similarly to the seat wall by leveling each block on our base material. We outline are steps and build them dependent on one another rather than being independent. This makes them much more stable and ensures the step heights are consistent. This involves some cutting and ensuring we achieve the height that we are looking for from one step to the other and the final step onto the existing porch. We also added hardscape lighting to the steps to add safety to the area when using the steps in the evening. The 4 foot step caps are placed on each of the steps and adhered using a hardscape adhesive.
We then prepare the base for the remainder of the patio by adding our base material to the final grade and compacting. The patio is screeded with High Performance Bedding or 1/4″ clean angular chip which means there are no fines / sand in it. We add a slope to our patio to ensure the water moves away from the house foundation and we add some areas in the wall for that water to drain right out of the system where otherwise it would be trapped.
With our bedding layer set, we can then lay our pavers on top. Along the seat wall we need to make precise measurements to apply to the pavers along the wall and to cut them into place. With all of our pavers in place, we can then install our polymeric sand. This sand solidifies but remains flexible for any movement the patio will experience. It is swept into the joints and a compactor is run over the area with a mat or pad to protect the pavers. The compactor consolidates the polymeric sand down to the bottom of the joint. The remaining residue is blown off of the surface and the sand is activated with a showering of water throughout the area.
And with that, our backyard renovation is complete and our clients can enjoy this for years to come.
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