Staying on Track
Thursday, March 25th, 2010Our project is complex and we’re doing our best to stay on track.
However, our non-maleable building materials (i.e., concrete, glass and steel) make it difficult to correct mistakes or make other changes and, consequently, we’re taking more time and money than we had planned for this project. That said, a LEED-H Platinum project, by definition, requires more thoughtful planning, material sourcing and handling, and documentation than otherwise. Especially in an earthquake prone location with increasing seismic conditions.
So, comparing our budget, timeline and other elements to traditional projects, which are generally energy- and resource-intensive, is not appropriate. But, no surprise, that comparison, and evaluation of our project management, is done by others every day.
If we were using traditional building materials with traditional construction methods (i.e., stick framing, wooden floor joists and roof rafters, baseboards and door trim) then we should be on a much faster timeline and a lower budget.
We just need to get over it.
Assembling the Lower-Level Flat Roof
Around the entire perimeter of the house is the ‘lower-level flat roof’. The ceiling height of this roof is identical to the existing house at 96 inches (8 ft). The only exception to this is the roof at the back of the house, which sits above the lower-flat roof, which we call the ‘mid-level flat roof’. Yesterday, the entire perimeter roof was completed as the mid-level flat roof connecting the Dining Room and Kate’s Bedroom was assembled.
Way cool.
Steel Flush Beam in SIP Roof
There is only one steel beam in our SIP roof and it is a flush beam that is hidden inside a SIP. This is a critical beam that supports the upper-level flat roof over the Atrium and allows us to have only one post in the Kitchen area. And, of course, have an extremely strong structure that meets the new code requirements for seismic conditions.
This steel flush beam sits on top of a lower-level roof SIP over the Garage and goes over the steel post in the Kitchen and is connected to a 7.00 x 11.25 inch Paralam beam that sits on the 8×12 Douglas Fir drop beam. This steel beam will carry lateral forces into the concrete wall in the Garage so it must be connected robustly to that concrete wall.
The fabrication of the steel beam must include:
- 5/8 inch Nelson studs to attach 2×6 nailers on the top and bottom;
- a hole in the top and bottom flange to connect the beam to a 5/8-inch anchor bolt that is embedded in the concrete wall;
- a Simpson GLT welded to the north end of the steel beam to connect it to the 7.00 x 11.25 Paralam flush beam;
- two sets of 5/16 inch stiffeners welded in the locations where there are vertical loads (i.e., over the concrete wall and over the steel column);
- four sets of plates welded to the flanges of the steel beam to connect to the 4×6 and 6×6 posts that support the upper-level flat roof; and
- four bolts connecting the steel beam to the HSS 4×4 steel column in the Kitchen.
The steel beam must be the correct length and each of the components noted above must be in the correct locations. Yeah, there is a lot going on with this steel beam.
Hosting Thien Doan’s Site Visit
Duquette Engineering designed the concrete foundation for the structure and Thien Doan did most of the work under Steve Duquette’s supervision. Thien was at our project site numerous times observing the drilling of the holes for our concrete piers as well as the placement of the reinforcing steel (rebar) in the concrete slabs.
When Steve Duquette attended our integrated project planning meeting on March 9, 2010, he said that he would like Thien to come by at this interim point in the project and take some pictures.
Thien came to the site today and walked the property with Bryan. Thien was most interested in the SIPs and how the SIP wall and roof assembly was designed to transfer the shear forces to the concrete foundation walls. Thien appeared impressed with the design and the construction, noting that there would probably be limited cracking of the sheet rock in the house during an 8.8 earthquake.
Reviewing the Shop Drawings for the Steel Beam with Larson Steel
Bryan drove to Larson Steel’s fabrication shop in Gilroy and met with William Zapeda to go over the measurements they took on Friday, March 19, prior to fabrication of the W8x18 steel beam. They went over each of the measurements, noting one key area where Bryan needs to confirm with the lead framer from Earth Bound Homes, Francisco Espinoz.
William and Bryan went in the yard and reviewed the actual W8x18 steel beam and measured it. The beam was a beautiful blue color, which is exactly what we would like the exposed steel beams and two steel columns to look like.
Finding Curb Damage in Los Gatos
The City of Monte Sereno requested that we have three 1-1/2 inch pipes carrying our excess water from our underground cistern to the curb on Winchester Boulevard, where it would then flow into the storm drain. The engineers from the Town of Los Gatos did not like this design and requested that we connect our underground cistern with an 8-inch pipe connecting directly to the back of the storm drain.
They cited potential damage and maintenance issues as the reasons for requesting this change. Today, Bryan saw a location where the 1-1/2 inch drain went though a concrete curb and had subsequent cracking and damage.
Now, we can appreciate the request for a direct connection.
ArchiCAD rendering showing the W8x18 steel beam and the lower-level SIP roof.
ArchiCAD rendering showing steel beam and posts supporting the upper-level flat roof structure.
Mid-level flat roof at the back of the house. This is where the three sliding glass panel doors will be located, which will go into a pocket behind the exposed concrete feature wall at the left of this photo (the Dining Room wall).
View from the middle of swimming pool to the front door, showing the mid-level SIP roof that was assembled yesterday.
Thien Doan, from Duquette Engineering, on the lower-flat roof over the Garage.
View of Master Study and Master Bedroom showing completed 2x4 wall under 6x10 beam in Foyer and pony walls ready to receive the posts and ridge beams to support the SIP gable roof.
Thien taking photos of the SIP roof structure.
Simpson Strong Tie HTT22 connecting the 6x6 post to the hollow core concrete panels. Solid.
LPT4s in the Master Bedroom, reinforcing the SIP walls to the 6x10 flush beams in the SIP roof structure.
Exposed feature concrete wall at the back of the house, showing the space for the pocket that will hold the three sliding glass panels. Note that we will be adding a drop beam under the mid-level flat roof.
Measuring the profile of the W8x18 steel beam in Larson Steel's yard in Gilroy
The W8x18 beam is 5-1/4 inches wide.
We like the blue color of the steel and are considering having all of the exposed structural steel in the house finished in gun-metal steel blue.
Concrete curb in Los Gatos, showing damage caused by the 1-1/2 inch pipe going through the curb.
At the end of each day, Jo-Anne does her best to drop by and review our progress. With the longer days and the time change, it is easier for her to do so. And, it is always good to see her smiling!
