The final foam finish at the perfect height (the yellow color is from UV damage to the top layer of the otherwise green colored foam)

The next step was to put the insulation under the final portion of the slab to be poured.  The guys from Spray Foam Energy Solutions (SFES) came out to examine the site, and asked for landscaping fabric to be put down over the sand (on top of the vapor barrier that is in turn on top of all that compacted earth) so that when they sprayed the foam down, it wouldn’t blow the sand all over.  So Catherine spent a day neatening up the site and putting down fabric.

landscape fabric over the sand

When the guys from SFES came out, they initially sprayed the foam a bit thin.  Our general contractor called them up and said that we needed a full 2” of foam to get the R value we needed (reminding them that they had assured us they could keep to a tolerance of +/- 1/2” thick which we had thought was impressive when they said that given how much foam expands…), well… then after they had touched it up, the foam was too thick almost everywhere (see next pic)… and our topping slab was not going to be thick enough to satisfy the structural engineer.

The foam when it was too thick

So the SFES guys were out there on a Saturday morning with their dust masks, and this really nasty looking powered steel brush that scraped the high spots off, and they leveled the foam until it was juuuust right… that was a dusty, hot, nasty job, and I felt bad for the poor guys out there doing that, but I got to hand it to them, they came in on a Saturday and worked until they made it right, and now we have a high compression foam insulation layer ready to have the radiant barrier laid down on top, and the final rough slab pour.

The foam being used is a soy-based closed cell expanding polyurethane foam made by Demilec called Heatlok Soya. So what makes a polyurethane foam green, and is that really possible??  Well, I went out and completely stole the following discussion and picture from a not disinterested party

Wire brushing the foam

Most all SPFs (Spray Polyurethane Foams) on the market contain sucrose or soy based content. There are different aspects to consider when discussing the “green-ness” of SPF as it pertains to the product’s composition. SPF is produced from the reaction of two components referred to in the industry as the A side and B side. While the A side is a petroleum based isocyanate, the ingredients that make up the B side will vary from product to product consisting of a blowing agent, fire retardants, surfactants, catalysts and polyols.

Material components of polyurethane foam

So what does this mean?  That there are still lots of petroleum products in the sprayfoam even when the manufacturers have maxed out the amount of recycled material or agricultural based oils that they can use in the product (found in the polyol part of the material), but because it is pretty much the best insulation out there, and the closed cell SPFs are the only insulation that will stand the weight of concrete above it… it seems like a good choice to make, as the petroleum use will be well outweighed by the energy savings of not pouring our heat into the ground.

Pouring the garage floor

Yes, it has been a long time in between posts.  All the details that had to be worked out to do the partial perimeter pour paled in comparison to the back and forth to finalize the forms for this pour!

Under slab plumbing

The final dimensions of the wine cellar walls needed to be checked and rechecked and checked again, and then misunderstandings about where the insulation was going to be, where and how the plumbing needed to be supported, and how high up it needed to be wrapped, and which parts of the slab were to be insulated from which set us back a couple of weeks.  This was complicated by needing any modification to be approved by the structural engineers.  It was finally a set of hand sketches of cross-sectional details initially drawn by Catherine then duplicated by our General Contractor Paul Delgros that were approved and we now all agreed what it was that we were trying to build.

Concrete forms

The resulting forms for the wine cellar area were the most convoluted set of concrete forms imaginable.  The wide footings for the straw bale library were in place with the embedded posts for the shear. So now the final plumbing was complete, the new forms were in place (the right place!), the insulated slab and the non-insulated slab were isolated at the correct parting lines, the structural engineer signed off, the city signed off, and we were ready to do the second pour to complete the non-insulated slab sections.

Natalie leaves her mark

Five concrete trucks and a “cleanup” poured tons and tons and tons of concrete into our massive slab.  The trucks were late, so the concrete crew was working into the early evening to finish floating the garage floor, which was lucky for us.  On our way home, we stopped in at the house site and were able to put hand prints and our names into the still wet cement in one corner of the garage – now the house really is ours!  Nat put her age in, so we had to follow suit…. someday 40 will seem young.

Forms for the library

We used 25% fly ash in the concrete which is a waste byproduct of coal burning and is often used in concrete to improve it’s pouring characteristics and its strength.   25% fly ash means that 25% of the portland cement in the concrete was replaced with fly ash – what that means in terms of total percentage of the final concrete is fly ash, I’m not really sure, but since the portland cement is one of the largest CO2 producing components of the concrete, displacing much of it is good from that point of view. The Minnesota Center for Sustainable Building research estimates that if you use 25% fly ash instead of the standard 9%, you get an 11% reduction in CO2 emissions in your concrete manufacturing.  It also improves the flow, and up to a certain point, the strength of the concrete (the maximum strength improvement comes around 25-35%).

Finish Floating

One concern occasionally brought up about high fly ash use is heavy metals from the coal burning such as lead, arsenic and mercury are now encased in your concrete, but I guess I’d rather have them encased there than sitting out in a leach field somewhere getting washed into the ground water.  Another concern sometimes brought up is that by providing a market for a byproduct of coal burning, you are supporting the coal industry… I find that argument a bit hard to believe – surely the US dependance on coal has very little to do with whether anyone can find a use for its waste products.  So using this waste product that in turn offsets high carbon production manufacturing seems green enough for us!

This felt like it was a long time coming, but when the day finally arrived, it was a still a bit scary.  Concrete is, well, concrete, and rather difficult (read: expensive) to change if anything is incorrect.  In the run up to the concrete trucks actually arriving, there were enough misunderstandings, tense discussions over drawings, and last minute corrections to practically send Catherine around the bend (questions like “why is there no place for a gas line to be routed through the foundation?”,  “why is there rebar passing through an insulated area?” and “does anyone, on any of these drawings have the correct measurement for where the wine cellar goes?” should give you an idea of the fun and games).
On the day of the pour, all of the issues for the part of the perimeter that was to be poured had been sorted out, and the pour went like clockwork.  Throughout this all, the guys from Atlantic Concrete have been extremely professional.  The forms they built were within a 1/4” at every point (when we gave them the right dimensions!), and I think we only found one measurement that was as far off as a 1/4”!

The machinery that pumps the concrete in is quite impressive.  The “Putzmeister” takes concrete in one end, pumps it up through a huge overhead set of tubing, and then putzes it right in place while the guys direct the incredibly rapid flow of concrete into the forms.

A day later, the forms come off, and there is a foundation perimeter wall.  There is still a lot of plumbing to be routed through the slab, and the footings in the garage and the strawbale library will be cast along with the main slab.  Given that two concrete trucks were needed for the perimeter wall, I wonder what kind of a parade of trucks we’ll have for that day!

After a couple of weeks of not much happening, this was a high drama week.  The guys who were going to lay out the concrete foundation came out and spray painted where the house was going to be based on the surveyor stakes.  On our Monday meeting with the general contractor, Catherine looked at the markings and said “uh oh – the house is in the wrong place!”. It was a foot too close to the Northeast fence – a foot we were required to have by code.  Luckily it was still in spray paint, and no excavation had started.  We stopped the excavation, and called the surveyor.  The next morning, the surveyor came out and explained that because there was uncertainty in the boundary because of the way the subdivision had been laid out in 1948, he couldn’t certify the southwest boundary to any better accuracy than 6”, so he had to move the house 6” away from that boundary, and he had simply moved it a foot (without mentioning this to anyone!), thinking that the driveway could be narrowed by a foot and still meet code.  Well, not so.  the driveway had to be 10’ wide because there is an accessory structure in the back… but it turns out the fence with the Northwest neighbor is 6” onto our property line, so when we rebuild that fence, we’ll move it.  So the house layout was moved 6” back towards the Southwest, and we’ll have to get the other 6” out of the fence – and then we’ll have a 10’ wide driveway that meets code.  So excavation was started up again on Tuesday afternoon.

But that made us start to think…. so on Wednesday night, Paul put the boundary lines into his solid model… and discovered that the porch roof overhangs the Southwest neighbor’s property line by 1 1/2 FEET!  This is a pretty major screwup.  The long suffering concrete guys were put on hold again.   On Thursday we met with the architect (who apologized profusely for the mistake), and after evaluating and discarding many possibilities such as rotating the house a bit, changing the roof overhang (it would really change the look of the house and mess up the passive solar), we devised a reasonable solution (hack the corner off the porch roof where no one will see it anyway since it faces the property line), and on Thursday afternoon, excavation was started again and by Friday afternoon, they had the perimeter concrete forms in.  On Saturday, Paul and Catherine walked every square inch of the laid out forms, and measured every length, and every diagonal, and it is accurate to within a 1/4”!  It is astonishingly precisely laid out – and in the right place!

The site this weekend… almost indistinguishable from the site a few weeks ago, except for those water tank inlets sticking up waiting to have downspouts trenched to them

It was a very quiet week on the build site… too quiet

After a parade of excavation equipment, excavating out large quantities of dirt, piling it up in a huge pile, bringing it back bit by bit, compacting, installing a water tank…. the site now looks identical to how it looked 3 weeks ago…  we were warned, but is still hard to look at it and feel like a whole lot of progress was made – but, and it is an important but, the ground under where the house is going is now solid and uniform, and when we pour a slab on it, it hopefully won’t settle unevenly and crack.

That was, after all, the whole point.

Loki tries to stow away to Korea

Next week while Catherine is in Korea, the footings will be dug all around the perimeter, and it will start to look like a construction site again.  In about 3 weeks we should have the foundation ready for framing… then it might actually start looking a bit like a house.

Leaf imprints on the concrete

Truth shall spring from the earth….The excavation for the foundation started this week.  The first step was to break up all the remaining concrete driveway around the perimeter.  While climbing around on the pile of broken concrete, Natalie found many leaf imprints which had been made on the underside of the concrete driveway when it was poured – an excellent find for a budding paleontologist.  We found and matched leaves from the local trees to as many of the imprints as we could.  Strange stuff keeps getting found during excavation, like mysterious

Natalie wishes she could find the keys

underground wires, large ancient tree roots for trees cut down more than 50 years ago, and old septic tanks, but these mysteries simply get stacked off to the side, and work continues.

After breaking up and hauling away the concrete, the footprint for the house plus an extra five foot perimeter was excavated down 2 feet below final grade, and the dirt was piled up in a new big pile. Then the dirt was brought BACK in to be compacted layer by layer so that it would have just the right characteristics… then on Thursday afternoon, the excavation guys panicked because it wasn’t compacting correctly.

Paul and Natalie play excavation

So we called the soil engineers who had specified this whole overly labor intensive and complicated process in the first place, and their solution was water – the ground was too dry, so we needed to water it to get it to compact properly!

So…. remember that last blog post about how precious a resource water is, and how much we need to preserve it, etc. etc.?  All out the window.  We had sprinklers going, watering the dirt to make nice compactable mud.

At least Natalie got to get niiiiice and muddy

Natalie’s field of mud

while skipping around in the mud field that one day will be a compacted enough pad to pour a foundation on.  And hopefully because we have done all of this, the foundation won’t crack nestled on all that nice and compacted dirt.

At some point, there will be actual building going on.  Promise.

Pink stakes

LIttle pink stakes are all around allowing the excavation team to triangulate to each of the corners of the house. Because they are about 5 feet outside the perimeter, the house footprint looks huge.

Not much visibly changed on the lot this week, but two important things happened.  The first is we got our replacement power pole.  Apparently the first one initially was the wrong kind, and the city didn’t like it, then it wasn’t braced correctly and PG&E didn’t like it.  Now hopefully, the new one is one that everyone will like.. and, more importantly, connect to the grid, as it really would be useful to have power on the site again.  You’d think the guys installing the pole would have known what was acceptable…

Power Pole

Hopefully this is now a properly braced power pole

The second thing that happened is the surveyors came in and put up the pink stakes everywhere showing where the corners of the house would be.  The excavation team had promised to show up “as soon as the stakes were in”, but the stakes were in last Monday… and they ended up essentially saying “um, just kidding, how about next Monday instead?”

When they do show up, a lot of dirt is about to start getting moved around, and they have to get going, because next Friday a crane is showing up with a 9000 gallon water tank, and there needs to be a big hole in the ground for it to go into.  The topsoil is going to be scraped off and set aside, and then the excavated dirt piled in the back yard for use in landscaping.  We did a lot of weeding this weekend so that the topsoil wouldn’t be full of weeds (but unfortunately it will be anyway)

3D Model of House

Paul’s Google SketchUp Model of the House

The architectural style of the house is “Zen Modern”.  You won’t find that style described in an architecture textbook, but there is a bit of talk about it in architecture circles as possibly a new “home grown” architectural movement in California (like the Craftsman).  So, we’ll either have a house that in 20 years is an example of early Zen Modern, or, more likely, no one will ever have heard of Zen Modern.

We didn’t go to our architect saying that was the style we wanted, but when we started describing open floor plans and rows of wooden framed sliding doors that let you live both inside and outside like Frank Lloyd Wright’s prarie and usonian architecture, use of stone and natural reed and wood like one finds in some Asian architectures, and a modernist line with minimal ornamentation (no crown moulding, no frames around windows, no baseboards), and a dramatic circular staircase…he said this was sounding Zen Modern.  Especially with our plans to have an informal California native garden with rocks (he initially proposed the pond, which has now become a pond with a seasonal stream with big rocks too!)

We will have lots of natural wood, polished concrete floor downstairs, wood floors upstairs, and smooth, but not shiny stone tile or counters throughout the house.  The inside doors will most likely have translucent panels with embedded reeds in them  (

View from front door

The view coming in through the front door


Reeds implanted in the door glass

We like the juxtaposition of the “clean” lines of more modern architecture with the relaxed lines of the natural materials.  After all, we live too cluttered a life to really live in a spare modern house.

Ground floor plan

The scan isn’t tilted off axis – the house is!  We have a 64 foot wide lot by 240 feet long which is a luxurious amount of space for the Bay Area, but friends from other parts of the country are probably just shaking their heads in disbelief…  This little shot of the ground floor starts to give an idea of what we are going to be building. Note the straw bale library! We are going to have the first straw bale construction in Mountain View so we’re keeping it simple and single-story, but we did get the permits, and the building department seems excited too.

Top floor plan

The top floor

We decided to orient the house off the axis of the lot so that it would use the space a bit better, and so that we could better align with the sun for passive solar.  The long series of double doors along the edge of the great room are all facing South (and towards the middle soon-to-be-riparian-paradise yard if you were paying attention in the previous blog entries).

No House!

The house is gone!

The old house is now gone, and next week the excavation for the new foundation begins.  We have a big open space ready to take a new house.


Great example of stream with stones

The middle yard (between the main house and the guest house) will be part riparian plants in the shady areas and part meadow in the sunnier area.  Riparian? For those who are not Scrabble addicts, and would have to look it up, it means essentially “around the banks of a stream or river”…. well, there isn’t a stream on the property, but Adobe creek does run through the back all the properties across the street, and there is real water in it 9 months out of the year, so we thought that constructing a seasonal stream on the property that we kept full with our rainwater storage for part of the year and allowed to dry up for the other part of the year would then give us the climate to plant lots of columbine and other native California riparian species.   We saw some very inspiring examples of constructed streams in local California native gardens on the California natives tour (like this one at right from a stunning native plant garden in Palo Alto), so we are now looking at how much big rocks cost, and hoping that there are lots of them on Craigslist….