Bridging the Gap Between Design and Construction Part 2

Continuing from last week’s site observations, the contractors have made remarkable progress by demolishing the existing garage. The cleared space is now being used to store the sand that will serve as the base preparation for the concrete slab, also known as a slab-on-grade foundation.

For early-career architects and designers, this video is more than just a guide—it’s an opportunity to see how the graphical hatches we meticulously sketch in construction drawings come to life on-site. One crucial component that wasn’t highlighted in Part 1 is the base preparation: a fine gravel or aggregate layer placed beneath the sand to enhance leveling and compaction, ensuring stability for the foundation.

Drawing from James Clear’s Atomic Habits, it’s essential to reward ourselves by observing how our hard work—our precise drawings—translates into built form. This act reinforces a self-reinforcing feedback loop, accelerating our growth and deepening our understanding of construction. By stacking this reward with the joy of seeing ideas realized, we create a powerful mechanism for learning and improvement.

When I was a beginner working at an architectural firm in New York City, I studied every construction drawing set in the office and made sure to ask senior architects and designers questions to help me understand the drawings. I still recall reading the drawings for the first time—it might as well have been written in Latin. The senior architects were all too happy to teach me in their spare time, often going beyond just answering my questions to explain the reasoning behind key details. Within a few years, I was able to walk onto a job site and truly understand what I was seeing.

Architecture is not just a static form—it’s a blend of art and applied science, brought to life by what I call the “Invisible Hands” that shape our built environment. These hands, often underappreciated, transform our lines into tangible spaces. At ATELIER X DESIGN, we think of architecture not just as shaping static forms but as a dance—unfolding in space over time. Every line we draw influences human movement through space, creating experiences with every detail we create. Let’s make each line a good one.

Pro Tip: Crafting a great building or interior requires 10% talent and 90% preparation. The more you invest in your knowledge base, the quicker you will be running your own project. Don’t be afraid to ask for help along the way. The best designers are those who never stop learning.

Foundation-Building Process

01 - Demolished concrete pavement, ready to be hauled away
Concrete debris from the existing pavement is dumped into dumpsters, ready for haul-away. This process highlights the enormous amount of labor required to demolish concrete, a material that is both heavy and demanding to work with. Each piece must be manually broken down, lifted, and transported, making this work one of the most physically challenging tasks on-site.

02 - Demolishing existing concrete pavement, per architectural drawings
The contractors carefully remove the pavement, generally following the area outlined in the architectural drawings. This step is essential to ensure alignment with the design intent and to prevent errors that could impact future construction phases.

03 - Concrete fragments manually loaded onto wheel barrel
Workers manually load concrete debris into wheelbarrows. This step emphasizes the physically demanding nature of the job and the collaborative effort required to efficiently clear the site.

04 - Scaffolding string lines, secured to existing concrete pavement
String lines are carefully secured to the existing concrete slab with great attention to precision. To prevent displacement by accidental bumps, contractors have added a hat mark the line, highlighting its importance. These markers help maintain accuracy for future steps.

05 - Foundation formwork complete, ready to pour concrete
The foundation formwork is now complete and ready for the concrete pour. This stage reflects the culmination of careful planning, measurement, and skilled craftsmanship. A well-built formwork system ensures that the foundation’s edges are straight, level, and properly shaped, preventing issues during the concrete pour.

06 - Existing garage partially demolished by hand
The garage is carefully removed by hand to avoid damaging the nearby foundation formwork. Demolishing by hand may seem less efficient, but it allows for precision, reducing the risk of unintentional damage to the surrounding area.

07 - Sand mound by the foundation for easier shoveling
The sand mound is positioned strategically near the foundation to make shoveling easier, requiring less labor. Meanwhile, the remaining portion of the garage is repurposed as a makeshift field office, demonstrating resourceful, on-site problem-solving.

08 - Rebar spacers fixing the rebars in place during concrete pour
Spacers are used to fix the rebar in place, ensuring proper clearance and alignment. Unlike chairs, which elevate rebar mats, spacers keep the bars evenly spaced within the slab. Tie wires are also used to secure the bars at intersections. The blue spacers fastened to the wooden formwork are anchors for the wood framing walls—more on this in upcoming video.

09 - Tie wires securing the rebars in place for the concrete pour
Tie wires are tightly wound around the rebar intersections, locking the framework into place. This step ensures the rebar remains stable during the concrete pour, maintaining the structural integrity of the slab.

10 - Bent rebar, tied and secured, ready for concrete pour
The rebar is bent and secured into position, forming a reinforced rebar framework designed to resist tensile forces. This reinforcement is critical for ensuring the slab’s durability and preventing cracking under stress.

11 - The rebar mat rests on chairs over a sand bed
The rebar mat is supported on chairs, ensuring that it maintains the proper height within the slab. This step is critical for ensuring even load distribution and preventing future structural issues.

12 - The rebar mat is bent into a cage, ready for pouring
The rebar mat is shaped into a cage, which provides the necessary tensile reinforcement. This ensures the slab handles forces from multiple directions, enhancing its overall stability and longevity.

13 - Sand layer levels, drains, protects the vapor barrier, and cushions the slab
The sand layer serves multiple functions: leveling the foundation, protecting the vapor barrier, and providing drainage to prevent moisture buildup. Beneath the sand is an RR base layer of finer aggregate, which improves compaction and settlement resistance.

14 - Rough plumbing set before concrete pour for drainage and utilities
Rough plumbing is installed before the concrete pour, ensuring proper drainage and utility placement. Unlike wood-frame construction, where plumbing can be adjusted later, slab-on-grade requires plumbing to be precisely finalized before the concrete is poured.

15 - Rain expected, tarp protects foundation before pour
To safeguard the site from rain, tarps are placed over the foundation, rebar, and excavated trenches. This precaution prevents water damage, erosion, or costly delays.

16 - Contractor sloped the tarp for drainage - great job
The contractor carefully sloped the tarp to channel rainwater away from the foundation. Without this measure, water could erode the sand base, weaken trenches, or rust the rebar, jeopardizing the integrity of the work.

17 - Tarp removed, trench intact with minor water entry
Despite the rain, the trench is in excellent shape with only minor water and debris intrusion. The contractor’s preparation for weather conditions proved effective. We are very fortunate to work with good contractors.

18 - Cleaning debris for inspection before the concrete pour
Before the final inspection, workers meticulously clean the site, removing debris to ensure a flawless pour. This step is critical to maintaining quality control.

Terminology

• Foundation: The base of a structure that transfers loads to the ground.

• Slab-on-Grade: A type of foundation where concrete is poured directly onto the ground surface.

• Rebar: Steel bars embedded in concrete to provide tensile strength.

• Formwork: Temporary molds used to shape and hold concrete until it sets.

• Spacers: Devices used to maintain proper clearance and alignment of individual rebars.

• Chairs: Supports that elevate rebar mats above the base to the correct height within the slab.

• Vapor Barrier: A layer installed beneath the slab to prevent moisture intrusion.

• Tie Wires: Wires used to secure rebar intersections, ensuring stability during concrete pouring.

• Bending Rebar: The process of shaping reinforcement bars to provide additional structural strength.

• String Lines: Tightly stretched strings used to verify the alignment and layout of formwork.

• Sand Base: A layer of sand that provides leveling, cushioning, and drainage for the slab.

• RR Base Layer: A finer aggregate base placed beneath the sand to prevent uneven settlement.

General Contractor: Barry Paster - Archwood Builders & Development, Inc.