It was another beautiful blue-sky California day today.  Our goal is to complete pouring concrete inside the house before Thanksgiving so that means we need to have the radiant heating/cooling PEX loops inside the concrete before each pour.

We need to pour concrete over the hollow core concrete panels in the living area and the garage on the main level, and then pour three inches of concrete in the lower level.  On the main floor, there will be 3 inches of concrete everywhere and 5.25 inches of concrete where we are having exposed concrete.  The other areas will have hardwood flooring in a 2.25 inch system (3/4 inch subfloor, 3/4 inch PEX layer, and 3/4 inch hardwood flooring).

Bill Brown was confident that his team wouldn’t be on the ‘critical path’ and that the radiant heating/cooling (PEX) would cause delays in meeting the Thanksgiving deadline.

The gauntlet was thrown …

Silicon Valley Mechanical Improves on Our Initial Radiant Design

Several month ago we started working with Ken Martin of Silicon Valley Mechanical to design the radiant heating and cooling, and the displacement air ventilation.  Ken is a Professional Engineer and has extensive experience with innovative projects, including David Kineda’s Z-squared building in San Jose, which David won a USGBC Northern California chapter award for (and was presented at the USGBC NorCal Gala on 10/30/09).

We had engaged Monterey Energy Group for the initial design of the radiant layout, which they did.  After meeting with Ken and reviewing the preliminary design with him, Ken identified a number of innovative improvements that could be made in a cost-effective manner that would allow for simultaneous radiant heating and cooling across zones as well as heating the swimming pool and cooling the wine cellar.

The highlights of Ken’s design changes included:

• Enabling radiant cooling by controlling humidity inside the house (to control the dew point and resulting condensation).
• Increasing the diameter of the PEX from 1/2 inch to 5/8 inch, which reduces the pressure drop in a loop.
• Placing the PEX on 9 inch centers (vs 12 inch).
• Using a loop layout so the average temperature differential between the supply and return PEX yields the same differential.

Placing Our First PEX Loops

Matt Jung from 88HVAC met Bryan at the project site and showed him how to take the PEX off the spool and lay out the PEX.  Matt has extensive experience with radiant heating and this will be his first radiant heating and cooling project.

We are tying the PEX to the #3 reinforcing steel (rebar), which is placed 18 inches on center each way.  Bill Brown cautioned us to ensure that no PEX loop should be able to ‘float’ upward as he will be doing saw cuts to control the cracking in the slab.  With the PEX loops pressurized to 100 PSI, Ken Martin believes that we should be OK.  Bill would have preferred to have the PEX under the rebar; for performance purposes, we will be placing the PEX on top of the rebar so it is closer to the surface (but safe from the saw cuts).

A perfect beautiful blue-sky California day to start laying out our PEX.

Before Matt arrived, Bryan used our shop vacuum to clean the debris from the perimeter voids around the hollow core concrete panels.

Matt working with Bryan to lay out our first PEX loops and zip tie the PEX securely to the rebar.

After checking the perimeter forms, Bill Brown’s team started laying out the reinforcing steel (rebar) over the hollow core concrete panels on our ground floor. There will be at least three inches of concrete covering all of the hollow core concrete panels.

Lots of Steel

In the living areas, we are using #3 rebar, 18 inches on center, each way.  Interpreting this, the rebar is 3/8 of an inch in diameter and it is put down in a grid, with each ‘square’ 18 inches by 18 inches.  The garage will have #3 rebar, set 12 inches on center each way.

Also, we are pouring concrete to two levels on our ground floor.  Where there is hardwood flooring, we are pouring 3 inches of concrete over the hollow core concrete panels.  Where there is exposed concrete, we are pouring 5.25 inches of concrete. 

Where there is exposed concrete, we will have the PEX tubing for our radiant heating set on top of the rebar.  We will have to ensure the PEX is fastened securely to the rebar so it doesn’t float up in the concrete where it could be damaged by the 1/2 inch deep saw cuts in the concrete that are designed to control the cracking that will occur in the concrete.

Starting to tie the rebar together.

The rebar is set at 18 inches on center, each way. The intersections are tied together with wire to hold the rebar in place until the concrete is poured and cured.

Setting forms by the Bridge Hall at the front of the house.

Forms in place at the front of the living room. This edge, with the concrete and steel I-beam, will be seen by everyone when they enter the house.

Rebar in place at the front of the house (but not in the garage).

Jorge recording hours at the end of the day.

It is good to see the rebar mat in place as we want to complete pouring concrete before Thanksgiving.

The surveyors from Dunbar and Craig were on site in the morning and the City of Monte Sereno inspection was in the afternoon.

We’re getting there …

Surveying the Foundation

Prior to completing the foundation, we need to have the backs of the forms surveyed so the City of Monte Sereno can be confident that the foundation is within the setbacks and is located as set out in the site development plan.

We requested our licensed surveyors, Dunbar and Craig, to survey the four corners of our house since the concrete feature wall in the dining room has been formed and will be shotcreted on Thursday.

Surveyors from Dunbar and Craig taking the benchmark from Via Sereno to the foundation walls.

(more…)

It was cold and raining last night.  We were treated (?) to one of the rare days when the Santa Cruz Mountains are dusted with snow.  The snow line was fairly low today and, when the sun came out, it was quite pretty.

Bryan had a meeting in Almaden Valley this morning so when he was there, he snapped a quick photo of the dusting of snow on Mt. Umunhum.

Snow on the peak of Mt. Umunhum.

(more…)

After such fabulous sunny winter weather, the rains are coming.  The team worked hard all day, knowing that the storms are approaching.

With more intense work in the basement, a solid set of steps into the basement was built, coming off the steps leading down from the driveway.

Steps into the basement.

The actual rough-in for the plumbing started today, with the first pipes being fitted to the sewage ejector.

Roughing in the plumbing

Rebar Arrives for Mat Slab

The delivery truck from Whitecap arrived with a load of rebar.  They brought a forklift, which unloaded the rebar near the steps to the basement.  Yes, it was carried down by hand.

The plumbing looks good - it needs to be attached to the rebar.

After arriving by truck, the rebar is now in the basement (by hand!).

Setting Up Tarps

In the later afternoon, the tarps were set up to protect the site from the storms, which will arrive late tonight and through the next few days.

Tarps in place.

Under the tarps on the west wall.

Under the tarps, looking east.