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.
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!