Archive for April 30th, 2009

Shooting 23 Yards of Shotcrete

Thursday, April 30th, 2009

Our feature concrete walls were completed before noon today.  This marks the end of the shotcrete; the next step is to place the steel beams.  Then, we will put the hollow core concrete panels in place.

We had an error in our design so Bryan picked up the demo hammer for a workout.  However, tonight he was able to enjoy the grand opening of the Margarido House (LEED-H Platinum certified) in Oakland.

Hosting Bill Clyne’s Visit to Our Project Site

Bill Clyne, CEO of Floor Seal Technology, was interested in our project and asked if he could visit the site (to check on Bill Brown’s work and our waterproofing).  Knowing Bill C.’s expertise with sealing, polishing and staining concrete, we said that we’d be honored to host his visit.

As background, Bill Clyne has done concrete finishing work for Bill Gates, Larry Ellison, Michael Dell and Jay Leno’s Big Dog Garage.  These people were able to select the best in the world to work on their homes.  Yes, we’re in a totally different league with our modest Eichler.

Bill C. arrived shortly after 8:00 am and took a quick tour of the site.  He liked the challenges of our project and our ambition to put 1.5 million pounds of concrete in place.  Bill C. and Bryan were in the temporary site office when Bill Brown knocked on the door and came in.  Bill C. and Bill B. have known each other for some time and are good friends.

Bill Brown (left) and Bill Clyne reviewing the plans in the temporary site office.

Bill Brown (left) and Bill Clyne (right) reviewing the plans in the temporary site office.

We discussed the project and asked Bill C. regarding the water in the concrete and how long it would take to dry.  Bill C. explained that the concrete would dry at approximately 1/2 inch per week so it would be several months before the concrete would be dry.  To retain moisture, he encouraged us to put a vapor barrier between the structural slab and our finished concrete (the top three inches).

The longer that water is in contact with concrete, the harder the concrete will be and the less shrinkage will occur.  Shrinkage causes cracking, especially in weak concrete.  We don’t want any cracking so we’ll ensure the concrete stays wet as it cures and that the water content is there for as long as possible.  However, we do want to have a dry house without any moisture in it.

Bill B. and Bill C. discussing the waterproofing as they watch the preparations for the shotcrete.

Bill B. and Bill C. discussing the waterproofing as they watch the preparations for the shotcrete.

Preparing to Shoot Shotcrete

Shooting shotcrete requires an air compressor and hoses to shoot the shotcrete.  Also, an independent third party inspector is required to confirm the nozzleman is qualified and observe the shooting of the shotcrete.

Dees-Hennessey's air compressor and truck.

Dees-Hennessey's air compressor and truck.

Special inspector from HP Inspections (white hard hat on left), with a load of concrete from GraniteRock and the Dees-Hennessey air compressor and operator.

Special inspector from HP Inspections (white hard hat on left), with a load of concrete from Graniterock and the Dees-Hennessey air compressor and operator.

Delivering Documentation to the City of Monte Sereno

Bryan delivered the first documentation from Innovative Structural Engineering to the City of Monte Sereno at 9:10 am this morning.  The Building Official, Howard Bell, asked for a letter and the reinforcing steel (rebar) schedule from ISE and the wet-signed rebar schedule from Duquette Engineering. 

Bryan’s second visit to the City of Monte Sereno was to deliver two signed copies of the ISE letter, which Howard stamped and returned one to Bryan (job site copy). 

A quick trip to Duquette Engineering in Santa Clara and then back to the City of Monte Sereno with the wet-signed sketch showing the rebar layout.

We’re good to go with the shotcrete.

Shooting Shotcrete

Shooting shotcrete is quite a process involving the full team to work together.  We had one of the most experienced teams working in perfect weather today as they shot 23 yards of shotcrete.  Graniterock delivered two 7-yard loads and a 9-yard load of 5,000 PSI shotcrete (30% slag) to our site, which was shot before noon today.

Shooting shotcrete on the feature wall in the kitchen.

Shooting shotcrete on the feature wall in the Kitchen.

Shotcrete covering the rebar in the Wine Cellar.

Shotcrete covering the rebar in the Wine Cellar.

Nozzleman shooting shotcrete on the back wall of the Wine Cellar.

Nozzleman shooting shotcrete on the back wall of the Wine Cellar.

Finishing with a steel trowel on the concrete feature wall in the Kitchen.

Finishing with a steel trowel on the concrete feature wall in the Kitchen.

Finishing the 18 ft feature concrete wall in the Atrium.

Finishing the 18 ft feature concrete wall in the Atrium.

Feature concrete wall in the Dining Room.

Feature concrete wall in the Dining Room.

Completed retaining wall in the south Window Well.

Completed retaining wall in the south Window Well.

Completed shotcrete wall in the Wine Cellar, which is under the garage.

Completed shotcrete wall in the Wine Cellar, which is under the garage.

Applying a curing agent to the shotcrete.

Applying a curing agent to the shotcrete.

The completed feature wall in the Dining Room is covered with plastic to retain moisture so the concrete will cure slowly to reduce the risk of cracking.

The completed feature wall in the Dining Room is covered with plastic to retain moisture so the concrete will cure slowly to reduce the risk of cracking.

Fixing a Design Error in the Exterior Stair Well

We made a design error in the retaining wall where the exterior steps will be poured.  Having made the design error, Bryan was to fix it.  Our on-site supervisor, Jorge Ramirez, provided instructions on how to operate the heavy duty Bosch chipping hammer.

Given the 5,000 PSI strength of the foundation retaining wall and the rebar in that wall, this was not a small task.  Bryan estimated 20 minutes to complete the demolition;  Jorge said, ‘Take 30 minutes.’

Location of the concrete retaining wall that needs to be removed (1:57 PM).

Location of the concrete retaining wall that needs to be removed (1:57 PM).

Results at 5:04 PM.

Results at 5:04 PM. Note the pieces of concrete that are still attached to the Grace Preprufe 160R.

Jorge cut the Grace Preprufe 160R, so Bryan knew where to remove the concrete to.  The interesting, and comforting, observation was the concrete stayed attached to the Preprufe even though it was in pieces.  This shows the strength of the bond between the Grace Preprufe product and the concrete.  This property is what will help to keep our foundation watertight.

Grand Opening of the Margarido House

Scott Andersen, Bill Brown, Matt Jung and Bryan toured the Margarido House on Saturday, January 10, 2009.  This was the second house in northern California to be certified Platinum under the LEED for Homes program.  The owner and builder, Mike McDonald, hosted our visit in January and invited Bryan to the grand opening.  The event was from 6:00 pm to 9:00 pm tonight.

Mike McDonald speaking at the grand opening of the LEED-H Platinum certified Margarido House.

Mike McDonald speaking at the grand opening of the LEED-H Platinum certified Margarido House.

 It was a perfect end to a very long day.