Old Town Permeable Patio & Fence Installation
The purpose of this work is to outline the scope of a project completed in July 2020 in Alexandria, Virginia. The project provided substantial improvements to the sustainability of the property by installing a permeable hardscape. All parts of the project sought to maintain and exemplify the highest industry standards possible with extra emphasis on sustainability standards as set by the Interlocking Concrete Paving Institute (ICPI) and Chesapeake Bay Landscape Professionals (CBLP). Please note, all prices associated with materials, equipment, and labor are given at the time of the projects, these figures are subject to change over time due to inflation and yearly increases in our business rates.
Consultation & Change Orders (07/08/2020)
The client reached out to our team at TLC for an estimate on converting a space behind her home from a monolithic concrete pad parking area into a more attractive outdoor living space. After meeting with the client on-site, our team recognized a few change orders that would need to be applied to the project in order to proceed effectively: they included relocating an existing HVAC unit from against the back of the house towards the end of the living space: redirect the client’s and neighbor’s downspouts/gutters; and waterproof the client’s foundation as well as the neighbor’s adjacent foundation. These changes to the existing stormwater infrastructure served to ease the burden presented by excessive rainfall during heavy storm events and ensure that the permeable hardscape would not lead to a problem with moisture in the basement.
Concrete Removal (07/08/2020)
To begin the project, we first were tasked with the removal of the existing concrete curb and parking pad, roughly 14.5’ X 30’. Starting with two jackhammers, our team quickly realized the concrete was fiber-reinforced and would require larger equipment for its removal. We then rented an excavator with a jackhammer attachment as a means of effectively breaking down this reinforced concrete. After demolishing the concrete, we utilized a mini-skid steer to remove the material. Though the excavator and skid steer saved large amounts of time and effort, this phase of the project was a long one as removal and disposal of the concrete required multiple back-and-forth trips to local recycling management facility, DC Material, where it would be recycled.
LABOR COSTS: $3,055.00
Project Manager Hours: 3 @ $105/hour= $315.00
Specialist Hours: 7 @ $85/hour= $595.00
Technician Hours: 33 @ $65/hour= $2,145.00
MATERIAL COSTS: $2,114.02
Jackhammer Rental- $450.17
Excavator Rental- $1,293.85
Disposal Fee- $370.00
PROJECT COSTS: $5,169.02
Fence Installation (07/13/2020)
Once the concrete had been broken down and removed, we could begin excavating the necessary soil from the area. After enough soil had been cleared, the installation of fencing could begin. After discussing with the client to better understand their landscape goals, we installed a fence of 4″x4″ pressure treated posts with an 8′ separation between posts. For the gate area, we installed two 6”x6” posts.
We utilized the extra-large posts so that they would be better able to support the weight of the large double swinging gate that would ultimately allow vehicular access to the paved area. It was the client’s decision to complete the fence installation as part of phase two. Therefore, we agreed that we would just install the fence posts in order to prevent potential disturbance of the hardscape area later on.
LABOR COSTS: $1,540.00
Project Manager Hours: 2 @ $105/hour= $210.00
Specialist Hours: 8 @ $85/hour= $680.00
Technician Hours: 10 @ $65/hour= $650.00
MATERIAL COSTS: $1,025.02
Misc. Supplies (Root blades, fasteners, screws, etc.): $187.41
PROJECT COSTS: $2,565.02
Subbase Prep, Change Order, Hardscape Installation (07/15/2020)
To begin preparing the subbase, we used a ZipLevel tool to ensure a grade that would allow stormwater to flow away from the foundation of the home. Once roughly 15 cubic yards of soil had been excavated from the foundation of the home, we installed strips of geotextile to minimize roots infiltrating the area. It was at this point we proceeded with the further excavation of a trench line for the reinstallation of the HVAC system in its new location, as per the aforementioned change order. With the foundation of the home exposed from the excavation, we applied a rubber-based elastomeric compound and strips of 40 mil PVC lining to assist in waterproofing the foundation of the home. Our team then proceeded with installing the aggregate base by first spreading a 4″ layer of No. 2 stone. Secondly, a 2″ layer of No. 57 stone. Lastly, a 1-2″ layer of No. 8 stone to act as a bedding layer for the brick pavers.
After educating the client on the importance of permeability in a hardscape, they were eager to make a paver selection that could positively impact the resilience of their home. Ultimately, the client selected Pine Hall Brick’s ‘Pathway Full Range’ brick pavers for the classic ‘Old Town’ aesthetic, a range of attractive red hues with charcoal accents. These bricks are not a traditional permeable paver, though, to help ensure that they would be permeable, we left the joints open to permit water flow. Our team then installed the pavers into a 12’ X 30’ area using a herringbone pattern, totaling 360 square feet of permeable patio.
LABOR COSTS: $8,032.50
Project Manager Hours: 6 @ $105/hour= $630.00
Specialist Hours: 17.5 @ $85/hour= $1,487.50
Technician Hours: 91 @ $65/hour= $5,915.00
MATERIALS & EQUIPMENT COSTS: $6,320.67
Hydraulic-Jack Rental: $95.78
Dumpster Rental: $1,500.00
Stone Base: $1,101.56
Geotextile & Anchors: $175.00
PROJECT COSTS: $14,353.17
TOTAL PROJECT COSTS: $22,087.21
Summary & Findings
This project exemplifies the opportunity for sustainability improvements in Old Town, Alexandria properties. Though there is not always a large amount of space to utilize, whatever space available can be optimized. Where other contractors would have built an impervious concrete slab, TLC constructed a sustainable permeable patio that will contribute positively to a more environmentally-conscious community. Additionally, this project will save time and effort for the homeowner in the future as the area will require less cleaning and regular maintenance due to its permeability minimizing the flow of debris.
Overall, we made improvements to the current hardscape through the addition of 360 square feet of permeable hardscape service that will result in an estimated 6,279.84 gallons of rainwater permeating more sustainably in 2021. (Calculated by taking square footage and multiplying it by the product of .623 gallons per inch of rain and Alexandria’s estimated yearly rainfall of 40”, then multiplying that figure by 70% infiltration rate). This project should be conceptualized as the standard by which regular home improvement projects in Old Town Alexandria can be repurposed to positively impact resilience and sustainability. TLC always looks to bring this level of insight and passion for sustainability to projects of any scale.