Part 2 – Demolition and construction of the landing
This post is the second in a series that describes the construction of an elegant but practical front entry. We go through the steps to provide you with how you can turn your front walkway landscape idea into reality. Let’s start with a look at the old stairs and landing area on the left. Now compare it to what was created on the right.
Before we could begin the walkway landing construction, we had to remove the existing landing. Normally excavation would take care of the job. Due to the ledge that the home was built on, the concrete of the old landing was fused to the ledge. This formed a huge rock and required hydraulic equipment to break it up.
Some people think demolition is easy. But first, we needed to determine if the current landing has a foundation. If so, is the landing attached to the house foundation? Thankfully, it was not. This house was built before the building code required that landings be attached.
If there is an attached landing, the contractor needs to carefully separate it from the home so as not to do damage to the foundation. Keep in mind that depending on your town, an inspection by the building department may be required at certain phases of this work.
Now that we are cleared to excavate the old landing, we need to completely remove the soil around and below the old landing. We are looking for virgin material that will pack tighter and eliminate possible settling of the new landing.
Creating the landing foundation
The landing will require new concrete footings at a minimum of 4 feet below grade. However, depending on the soil types we discover, the concrete footings may need to be deeper. In a project like this, we are looking for non-organic soil, preferably gravel as the foundation for the landing area. If these soils don’t exist, we will need to excavate more materials and add crushed rock and compact in lifts, to bring the ground back up to starting grade.
The bottom of the hole needs to be level and dug out by 1 to 1.5 feet larger on all sides than the finished size of the new landing. Once the crushed stone base or virgin ground gravel base is level and compacted, footing construction can begin.
Walkway landing construction begins
Footings are constructed with poured concrete, leveled to ensure the base of the landing is solid. Now we begin the construction of the concrete footing. After careful measurements are taken, we build a wood form in the hole. The importance of having the footing square and level cannot be over emphasized. Once forms are built and secured in the hole, we pour and level the concrete to the height of the form. The top of the concrete is screeded level with the top of the form and keyed to accept a concrete modular unit (CMU) which will be built on top of the cement footing.
We place the CMUs on the cured footing using mortar, forming the framework for the landing, with their outside dimensions being the same as the proposed finished landing. The CMU are built up to or just below the finish grade height of the landscaping, as these are raw looking and we don’t want it to be visible. We pin the CMUs to the house foundation using rebar pins drilled into the concrete house foundation. This ensures there is no movement or separation from the house.
After the CMU framework is completed and cured, we backfill with crushed stone on the inside and existing site soils on the outside. Before we backfill, we spray a concrete sealer on the below grade foundation for extra longevity.
Backfilling is done in 8 inch lifts to ensure no settling later. In other words, we compact the soil and aggregate fill with a plate compactor machine every 8 inches. Water is used to aid in soil compaction.
The finishing touch
After the backfilling the substructure is complete, the landing construction work can begin. The materials chosen for this job include Brussels Dimensional Stone by Unilock. The antiqued or weathered appearance of Brussels Dimensional Stone is a great alternative to expensive natural stone products. These blocks will form the outside of the landing and stair risers to give it a finished appearance. While we construct the framework using the Brussels Stone, we backfill the inside with crushed stone and mortar. Once the overall height and stair landing layout is complete, the inside is filled with crushed stone to within 4 to 6 inches of the top layer of Brussels Stone. The remaining area is poured concrete with rebar pins locking the three sides together along with concrete wire mesh.
The final phase of building the landing is to install the stair tread and landing materials. The material chosen is bluestone, an attractive and durable material that comes in many complementary patterns and colors. We cut the bluestone onsite for the perfect fit. We set the bluestones on the mortar bed, and then we grout the joints. The completed landing will now need to cure. We will then acid wash the landing to seal it for longevity.
The key to a solid, long lasting quality landing is paying attention to the preparation of the foundation and ensuring it is level and stable before building the landing. Many landscape construction contractors make it look nice on the outside, but it is what’s inside that counts.