Completing interior spaces provides great satisfaction in experiencing each room after many months of planning, design, and construction.
The new challenge is to work efficiently within confined spaces. Temporary storage of materials and equipment occupy space to be finished, so careful logistics and organization are needed to save time and effort. Lumber is very heavy and cumbersome to move!
Designing the roof parapet was part of the permit submittal and approval. It was important to make sure that the assumptions for the design were correct. The height of the roof parapet had to be confirmed before waterproofing could be applied to the roof.
In order to maintain minimal impact on the neighborhood and balance proportions viewed from all sides, we checked the height of the parapet from across the street. It didn’t hurt to get some friendly input from our neighbor.
One loop thrown at us was wet weather–not the kind of driving rain that predictably hampers a construction site in the winter–but “the coldest winter I ever spent was a summer in San Francisco” kind of weather. The pebbly fog hung around for weeks in late July and early August–forcing us to delay finishing the waterproofing and window installation.
Finally, the skies parted and the grayness dissipated. The roofing insulation and waterproofing membrane were added after completion of the roof and parapet. Note the difference in the weather from the photos!
Being located in the rear yard was ideal for the ADU, but it posed temporary challenges for providing delivery access. Fortunately, the side of the house was just level enough for large trucks to move supplies as close as possible to the back. Felix had a field day watching the speed and skill with which drivers were able to shunt and offload heavy loads.
Part II The Core (Weeks 48-54)
With the end of Rough Framing and the start of the third and final phase for Interior Finishes, we happily shifted gears. Previously, it felt painfully slow as we hurried and then waited for action. With multiple possibilities and combinations of skilled labor and materials, we were often faced with making decisions that could impact the project later.
For the exterior walls, waterproofing was smeared over the nails and knotholes forming scabby polka dots to allow for the inspector’s scrutiny. Then, the rest of the waterproofing was applied to the exterior walls to form the underlayment for wood siding.
After the windows were installed, it no longer felt like a shell. We could really visualize being occupants in the space!
Passing rough inspection was a red-letter day. It officially determined the completion of the second of three construction phases. With rough framing behind us, we could proudly identify ourselves not only as owner and architects, but builders as well.
Coming Up: A diversion to…Munich and Bayreuth, Germany next!!!
This month’s activities includes installation of windows, building the stair between two levels, and waterproofing of the exterior skin. Both the roof and exterior walls need good moisture protection, so additional care is being taken to check details with a waterproofing consultant.
In addition to interior wall framing, shear walls between the existing house and new addition have been added. You can see a portion of the wall along the stair to the right in the photo below. In the next photo, deck rails have been built. The roof parapet will be built next, providing protection for a future deck and extending the roof approximately 42″.
Miscellaneous windows and exterior doors were ordered, and planning for interior finishes and equipment went into high gear. While we thought that ordering materials and products would create issues with delivery and material availability, the problem was not as great as imagined.
There are always alternatives if you are flexible about the products, and since we were not providing custom or high end finishes, we could work around lead times and locally available products. Out of the items for kitchen casework through Ikea, appliances through a discount broker, and plumbing accessories appear to be within reach, at least at his point before actual ordering takes place.
Wind rather than rain is a deterrent to working on site. The gusty coastal weather has been downright unpleasant at times and chills you to the bone. We can’t wait for the autumn weather when the winds die down, although we may be in for some unpredictable air quality from fires.
With the existing kitchen and dining room out of commission, it has been a challenge to prepare and eat meals. On top of that, the ambient temperature in these rooms average around 50 degrees. The heating bill was over $700 last month until we realized that the exposed air was sucking all the heat out and the thermostat was registering the coldest past of the house!
Felix has lost his viewing stand from the dining room window and can only wistfully catch glimpses of Mom and Dad during bathroom breaks or snack sneaks. The roof obscures all the active work taking place inside the new space, so there’s no opportunity to view activity from above when roof joists were previously open and exposed.
As an alternative, Felix has watched street construction down the block. His beloved dump trucks, bulldozers, and and excavators are all readily available in full operating splendor during his daily strolls. They complement his readings from favorite construction books. He never tires of hearing them again, even on the sixth or seventh time in a row.
Even as an architect, it is difficult to appreciate the complexity and skill it takes for homebuilders and contractors. Unless you are living and breathing on the site 24-7 as we are, you are unaware of the active thinking, eye-hand coordination, and immense challenges it takes to build a structure from scratch. This giant sculptural baby is taking form and unwinding each day, with distinct progress and satisfaction gained.
The Second Story
After completing the floor joists and the subfloor for the second level, we began constructing the exterior walls. The master bedroom and bath will be located on this level.
Walls were first assembled on the floor, then tilted into place with “stoppers” to hold the wall in place. Finally, the sill plates were nailed to to floor and voila! The structure defines the edges of the rooms to be finished in the final phase of construction. Glimpses of the Pacific Ocean and Golden Gate Bridge make this monumental effort worthwhile.
Hoisting a heavy prelaminated beam in place became the next challenge. At 24 feet long and a heavy member, the beam arrived by truck from Golden State Lumber. It caused a brief sensation on the block as neighbors are not accustomed to seeing large scale deliveries for construction in such a quiet, sleepy environment.
The process was swift and completed in a matter of hours. A simple hoist raised and positioned the beam into place.
Once the prized beam was unwrapped, roof joists could now be quickly built to attach to the main spine and to enable roofing to be installed over the joists. The joists and beams formed a chorus line where the music and dance of the musical all came together!
Because the roof joists were going to be exposed, each member was hand selected and its exact position in the chorus line was determined. Additional care was taken when plywood roof sheathing was installed to avoid any exposed nails. There was no room for error here.
At the same time, scaffolding was erected along two sides of the structure for installation of windows and exterior material. When the roofing material is installed, the entire structure will be sealed and ready for the final phase–interior finishing!!
The Felix Factor
Stay tuned as Felix sees the unfolding of the third and final phase of our on-site construction project! Don’t forget to write home!
The bone dry weather has serious outcomes for the Bay Area and California, but for us the lack of rain has helped us. So far, we have been able to continue building the ADU. Where we sit on a bluff, strong winds have been more problematic.
Still, there are many other challenges. A two-person crew, trained as architects, are learning to become builders. They must make many decisions about basic construction– how to organize the means and methods of building, order materials and equipment, and master the tricks of the trade.
Problem-solving on the spot may not happen as quickly as expected, particularly as each choice affects the next task or decision. Building a new structure connected to an existing residence requires complicated tie-ins and repair to areas where the exterior skin and window were removed. Eventually, solutions surface and we were able to move forward. Teamwork and collaboration are the keys to working toward a common goal, along with communication and trust among team members.
Recap of First Floor Walls
As you may recall from the previous post, we had completed the first floor wall framing. The video walk-through below gives you a real-time sense of the space from the end of the unit, containing the Office, Living Room and Dining Area. You can also see the small window along the north side in the kitchen and the view of the entry into the unit.
Architects think of building systems as analogous to those in the human body. Plumbing systems are similar to our digestive system, electrical systems are like our central nervous system, and ventilating systems are like our respiratory system. The beams and columns form the structural system, just like our bones do. So yes, creating a building from scratch can feel like a powerful act.
As we continue on our journey to build and complete the ADU, we will be referring to these building systems as they are developed throughout the construction process.
The Second Floor Framing
Wood construction uses many of the principles we learn as children when we played with blocks and legos. But the actual joining together of materials and elements require some additional skills. It helps to think three dimensionally and have a sculptural understanding of shapes and planes. A complex structural design to address an irregular shape and site configuration raised the bar for these skills.
After last month’s challenge constructing the wall framing for the first floor, the next hurdle was the floor for the second story. Referred to as a “diaphragm”, the combination of plywood sheathing and floor joists stabilizes the walls below when the two vertical and horizontal planes are joined together. They now form a box that work together.
In the video above, you can see the walls of the first floor below. They support the upper floor. At the edge, a 3 foot cantilever extendsover the first floor walls to provide more floor area for thesecond story above. It will be one of our last opportunities to “see through” this space before it is covered up.
Completing the Floor for the Second Floor
With the plywood sheathing attached to the floor joists, we finished the second story subfloor! The 3/4″ plywood is keyed with a tongue and groove system so they attach and seal together at the edges.
In the video, you can see that the wall framing for the north wall of the second floor Master Bedroom has been built on the ground. The completion of the second floor provides a usable work surface for building the exterior walls before they are tilted into place.
This is the latest photo of the second floor exterior wall erected yesterday morning. The master bedroom window frames a view of the Golden Gate Bridge above the tips of the 50-year old junipers!
Foreman Felix continues to watch from his control tower, except that now he can see his crew directly in front of him at the same level. He joins the conference on the mound while having a refreshing mid-afternoon snack.
Foreman Felix had time to get away every now and then from the job site. He managed to raid the kitchen pantry and found a treasure trove of tasty new toys hidden within.
Stay tuned as the story (the second story) unfolds!! Don’t forget to write home!
The first real sense of seeing the interior space and the spectacular view from the office window was thrilling to see. We could actually witness the results of many months of planning, designing, and building our ADU (accessory dwelling unit).
Still, more heavy construction work was ahead of us. Two steel beams arrived from the fabricator and stared us in the face: more calculating and logistics on how to erect these 800-lb gorillas. It took a few days to prepare the existing structure and get the necessary equipment to erect them safely.
Headers and Footers
After getting refreshed over the weekend, Team J&J erected the two steel beams. With help from the rented lift and a portable scaffold, each beam was placed to form a 3′ overhang over the deck. The overhang provides additional floor space for the upper level and also shading for the windows on the first floor.
Once the steel beams were placed, the edge beams to support the upper floor were installed between the steel flanges.
With so little tolerance to work with in joining all of the angled walls, the wood beams required several attempts and shaved edges in order to fit them inside the steel flanges.
Finally, a perfect fit!!
A Footnote: Multi-tasking in the Front Row Seat
Felix continued to dominate the box seat to watch his crew staying on the job. While he kept an eye on them, we watched his new skills as he learned to enjoy the freedom of feeding himself!
Onward and upward! Next in store will be floor joists and stud walls to finish the first floor, and window installation. Stay tuned for more fun, and don’t forget to comment!
As the Bay Area was blessed with torrential rains over Thanksgiving and December, our secret hopes of a dry winter were dashed. Fortunately, the exterior foundations, concrete slab, and exterior deck framing were completed before the slushy weather soaked the property. Ironically, a 50-year old juniper tree collapsed, which was caused by the drought but too weak to be saved by the downpours.
The bids we received for rough framing often varied drastically, so we made a point to receive multiple bids for each scope. The foundation bids seemed exceptionally high, which were due in part to the difficulty of the structural design and the fact that contractors are in very high demand in the Bay Area (a natural side effect of a hot housing market and an uptick in renovations during the pandemic). In the end, we took what we could get. Knowing that the foundation is perhaps the most crucial part of a project that should not be compromised, we took a deep breath and signed on one of the higher bidders.
Once the complicated foundation was completed, we were left with a dilemma. The pier drilling took much more time and money than expected, so we rebid the rough framing work. Earlier conversations raised the possibility of self-performing some of the work. As property owners, we were allowed to serve as our own contractor.
Originally, we had considered self-performing some of the finish work. Constructing rough framing for posts and beams all by ourselves seemed like a daunting task. The thought of getting the budget back on track together with the opportunities for learning the nuts and bolts of construction made a compelling argument for pursuing self-construction.
We had already planned, designed, and prepared the detailed working drawings for the project. The permit was approved after two years of being at the forefront of complex ADU (Accessory Dwelling Unit) requirements. The foundation that took nearly three months was now complete. After many discussions, we collectively agreed to forge ahead and do the framing ourselves.
We drafted a written agreement among the team that mapped out the costs and schedule for Rough Framing. Each of us signed and committed to making the framing portion of the project a reality. Between three architects and a baby, we combined all our professional skills as a structural engineer, contractor, designer and planner all into one pot.
Before the December rains, we framed the exterior deck, which would serve as an extended work surface. A complicated stepped grade beam in the existing basement was still not complete. We made the most of inclement weather and built the grade beam ourselves. After some changes to the structural design, we were able to avoid a costly change order.
Interior Grade Beam Construction
First, we excavated the area surrounding an existing interior footing, around which the new grade beam would be poured. Next, we bent the reinforcing bars by hand with two hickey bars to create the rebar cage. We drilled and epoxied new rebars into the existing foundation to connect to the new cage. Our special inspector was willing to advise us on the steps needed for the work to be approved. He even complemented us on our rebar craftsmanship when he came back to see the final product!
Once the rebar cage was tied and we’d gotten the necessary inspections, we placed the formwork for the concrete.
After calculating that it would take more than 50 bags of mix-it-yourself concrete to pour the grade beam, we decided to treat ourselves to a concrete truck and pump. The pump operator gave us a few tips on how to vibrate the concrete (not too much!) so that it would settle evenly and finish nicely. Concrete is similar to baking: make sure the proportions are correct, don’t mix it too much or over-work it, and make sure to use the proper techniques to allow it cure at the given temperature.
After the concrete was poured, the formwork was removed, and voila! A grade beam!
Building the grade beam demonstrated that we could do at least some of the work ourselves! After working well into the night to make sure the rebar and formwork was ready for our concrete pour, we took a brief holiday break for Christmas and New Year’s.
Structural Steel Support
Meanwhile, we confirmed calculations with the structural engineer for a modified steel column and “Kicker Beam” which would connect the addition to the existing house. We worked directly with a structural steel fabricator in the Bayview.
The fabricator delivered the post to our site and allowed us to borrow his hoist to erect it. We built a temporary structure through the second-story window to support the hoist. The hoisting went smoothly, but once it was vertical, attaching it to the existing structure proved to be a huge challenge.
First Signs of Exterior Walls!
With the post finally installed and the sill plate anchored to the slab through a series of cast-in-place bolts, the wood framing members finally began to go up. Heavy PSL beams were set in place with the help of a rented material lift. The edge of the addition and its distance to the rear property line is now visible and a real sense of the three-dimensional space was evident. We put up the header and sill for our first window — a perfect frame for a crystal clear view of the Pacific Ocean and Point Reyes beyond.
We can’t overlook our cheerful foreman, who supervises all construction from the corner window to make sure we are on time and within budget. Here, his conscientious staff erect the first column and complete the second of three major beams as he watches from his viewing tower.
We hope you enjoy these constructive travels! We are about one-third of the way towards our goal of completing the ADU this summer. Thanks for joining us, stay tuned, and as always, your comments are welcome!
Our ground floor slab has been completed! In the photo above, me (and my shadow) are standing on the ground floor where the living/dining/kitchen space will be located. I am facing the new entry area where I will be greeting you at the door. You will be waiting outside, where the gravel is shown!
We were very relieved to finally see the results of the foundation work after several months of hand wringing. As with all construction projects, you somehow reconcile the realities of time and budget. Expectations always exceed reality, and you are forced to make some hard decisions. You learn a lot about the business of construction, the players, and the many moving parts that come into play. You come to accept and live by those hard choices that had to be made.
Difficult conditions on a small sloping site created challenges for the foundation crew. While most of the pier drilling went smoothly, there were a couple of stubborn piers in the middle that refused to cooperate. These were clearly aggravating the drilling crew, yet they pursued and prevailed. At times, no one wanted to breathe for fear of causing a collapse of the openings.
Aware of their concerns but unable to affect any change to the site conditions, I watched from the dining room window. The crew hacked away at the sandy soil, drilled through and extracted dirt and rock, force-fed the steel casings, lowered the reinforcing cages (some 30′ long), and injected the concrete.
We watched this dramatic choreographed performance unfold each day. The huge drill plowed within inches of our window. At times, I thought it would smash the window or crash into the side of the house! The exposed wall of the kitchen concerned us as a few leaks threatened to derail our comfort, and a few vibrations kept us wondering whether we were going to be shaken into homelessness.
As it stands, the foundation crew knew exactly what they were doing, where to place their equipment, and drill the holes. I was grateful to the care and precision they used. Their expertise is the lynchpin of the project.
The concrete work for the retaining wall went quickly following the pouring of the piers. Before we knew it, the slab was topped out after the layers of gravel, foam insulation, moisture barrier and rebars were set over the backfill. We could revel in the delight of finally “getting out of the ground” and declared the first phase of the ADU completed.
Phase Two Construction of Rough Framing has officially begun, with the deck supports being tied to the retaining wall. The deck framing will provide a work space for the ADU construction when framing work begins. Interior finishing will complete the project during Phase Three.
Recap of Phase I Foundation Work
This video represents a year’s end celebration of our work and efforts toward building the ADU.
We hope you have enjoyed following the journey building the addition to our house. We wish everyone a safe and joyous new year. Let’s look forward to the great new adventures ahead for all of us!
While the previous two months seemed to drag with the drilling of the piers, there was a lot more to observe during these two months of construction of the ADU (Accessory Dwelling Unit). As the structure lifted itself from below ground, we could witness progress of the construction. We were gratified by physical signs finally appearing after two years of planning and design!
Temporary formwork was built for a concrete retaining wall and grade beams along the perimeter of the addition. There seemed to be as much, if not more, effort put into the construction of the forms than the pouring of the concrete itself, which seemed easy after the complex engineering and layout of the entire space. Needless to say, all of the work that will ultimately not be visible—the drilling of the 30 foot piers, the intricate network of rebars, the wooden formwork that holds the wet concrete—is just as essential as what one sees.
Once the concrete was poured, the formwork was removed. It was sad to see all the hard labor put into its construction disappear so quickly.
House of Sand and Fog
Next, the sandy soil made its reappearance on the site. The backfill was compacted into the large bowl created by the concrete walls.
Layers of Icing on the Cake
Within one week, the finishing touches and crucial layers of protection under the floor were added: 6” of gravel followed by a 2” layer of insulation. Finally, the moisture barrier (yellow plastic material) was added to the underside of the slab.
Dear Little Felix had a field day watching all of the activity, keeping him entertained throughout the day. Watching and learning outside our window was a great home-bound alternative to traveling around the world to see the sights!
The Dining Room Window gives us a front row seat of the ADU (Accessory Dwelling Unit) construction in our back yard. For much of the last two months, it felt like watching the grass grow at times, and sudden operatic performance at others. There was plenty to consider, ponder, and worry. With the rainy season emerging, there are additional concerns about weather protection and drainage. Nevertheless, the substructural work inched forward with big digs, long tubes of steel linings welded end to end, gnarly steel cages, and finally concrete.
Recap of Weeks 2- 4 (The First Pour)
During the first weeks of foundation work, the crew mobilized their equipment and laid out all the positions for the piers. They began by drilling the first four pier holes along the edge of the existing house to support the addition and to underpin the existing foundation. As mentioned previously, our site is basically a sand dune and the loose soil is prone to caving. Getting to the 25+ foot depths required by the soils engineer proved to be arduous.
To reduce the risk of caving, the crew poured the piers in two stages. The initial pour included the five 25+ foot piers and seven 8′ deep deck piers. Photos below show the arrival of the truck and equipment assembled for the first concrete pour.
Most of the time, our site looked like a giant bowl of flour! In the beginning, the excavator scraped the edges of the bowl and pushed the floury dirt around. It felt even more similar to baking when the concrete was finally pumped from the hoses during our first pours. The liquified concrete pouring out of the hose looked like thick whipped cream extruded from a pastry tube, but not as appealing.
The foundation crew continued to drill holes, insert steel casings and rebar cages for seven “shallow” deck piers. These piers were drilled approximately 20 feet to bedrock. The sandy soil continued to present challenges, as the soil had no compressive strength and collapsed when drilled. Geo-grout was used to stabilize the openings so drilling could be accomplished more reliably.
It was very humbling to watch as each day’s events unfolded. Every crew member was fully engaged. The video below shows pier holes being drilled by the excavator and a crew member guiding the drill into position while another crew member cleared the sandy soil from the drill. A fourth crew member checked and adjusted the grout in one of the piers.
Week 7 (Pour No. 2)
The final stage of earthworks began. The crew drilled the five remaining 24″ wide holes for the piles that support the addition. The cement truck returned and issued the second installment of concrete.
As in the first pour, the geotechnical engineer, the city building inspector, and the special inspector reviewed and approved the excavation and reinforcing steel before the second concrete pour. Our construction manager choreographed the intricate dance between consultants and contractor.
Once the steel casings were put into place and the holes were drilled, the steel reinforcing cages were guided into place with the excavator.
You can get a sense of the depth of the opening by the height of the caging, which in some cases were over 30 feet long. In order to lower the cages smoothly along the full depth of the opening and to ensure enough clearance for the concrete to be poured around it, the crew attached rolling spacers in intervals at vertical bars along the edge of each cage.
Daily spot checks from Foreman Felix ensured that the construction manager was on site during this stage of construction.
We mobilized our brains and prepped areas of the existing house to make room for the major home addition, which will consist of a kitchen/living dining area, two bedrooms, two bathrooms, and a small office in the rear yard of the property. All of the existing kitchen casework and appliances were removed for a new kitchen reconfiguration.
Week 2: Breaking Up Isn’t So Hard to Do!
First, two sets of old and deteriorated exterior stairs were taken apart to make way for the new addition. Then, the cantilevered portion of the kitchen that projected into the future new master bedroom area was demolished. Finally, the gaping hole in the middle of the house was covered with a temporary wall. We no longer felt as if we were living in a dollhouse!
Our foundation contractors arrived to set up their work. Their first task was to remove two old juniper trees and branches that hindered access to the site. A medium-sized excavator with a jackhammer attachment arrived to cut up the concrete pad, making way for seventeen piers to support the new structure. Ten 25+ ft deep foundation piers will be cast into bedrock and seven shallower, 8 ft piers will be drilled for the deck.
With the slab broken into chunks, the excavator and bulldozer worked in tandem to remove the concrete rubble, loose rocks, tree roots, dirt and debris in a confident, orchestrated tango. Dancers, efficiency experts, and strategists could learn a lot from observing these moves, as we did.
With a box seat in the corner of the dining room overlooking the patio, Felix was fascinated by the unusual activity right outside the window. He watched ten minutes at a time and could have easily lasted longer. He did learn how to cover his ears, however, and practiced using his hands as sound buffers. You’ll hear more from him later.
Week 3: Holey Moley!
The foundation contractors began drilling four 18″- diameter holes up to 31 feet deep along the existing house to support concrete piers for the new addition. Six-foot long steel casings, soldered end-to-end, were immersed into the ground to prevent the soil from collapsing along the entire length of the hole.
Being only two miles from the Pacific Ocean and on a hill, our soil conditions are what you expect from a windswept, coastal environment. The original sand dunes with deep rock underneath produces fine, dry, soil with no compressive strength; it’s so loose that the drill appears to wallow in water. The excavator drilled the four piers with a rotating auger bit that avoided vibration and noise of other methods.
Only the soft whirr of the excavator could be heard during normal weekday work hours. Undeterred by noise, Felix was fascinated by the cacophony of new sights and sounds.
Coming next: Concrete solutions to constructive traveling