Wednesday, September 29, 2010

Construction status (foundations, basement, garage)



The root cellar/basement walls are complete, the garage concrete and framing is complete, and most of the two story section of the house has footings poured. Structural steel/welding is happening as I type. There’s been lot of head scratching going on thinking about how and where to route plumbing (water, gas, waste, storm water collection, vents, hydronics) and electrical wiring (power, sensors, telecom) prior to pouring structural slabs and beginning ICF wall construction. Even with all of the careful planning, I don’t have any expectation that we won’t have some surprises to deal with later.

There’s nothing terribly interesting about the garage. It is detached and no need for stellar thermal and energy performance, so it is framed and sheathed in the conventional way. Adding “Thermafiber” (foil backed OSB) to the garage roof was a simple and cost effective way to reduce heat gain. Foil addresses heat radiated through the roof, one of the three ways heat is transferred. Very simply put, the other ways are conduction (through a solid) and convention (through a fluid/gas). This is why typical fiberglass insulation caries a foil layer on the back of the paper (fiber side), to reduce both conducted and radiated heat gain. Foil has a low emissivity coefficient and radiated heat transfers directly proportional to the emissivity of the material.



Kitty hired a male model to wire the garage ;-)



On belay! (Nacho and Rourke)

root cellar and garage




















The root cellar walls are complete including water proofing; a system from Tremco that includes a polyurethane sealant (caulk), Tremproof “black snot” barrier, MiraDRAIN barrier protection sheet, and filter cloth. First the CMU joints were caulked, brushed over again with black snot and then the entire wall surface got two coats of black snot. On the outside walls where storm water and irrigation water can seep though the soil, there is a protective barrier sheet over the black snot and two feet of drain rock outside of that. It seems unlikely that water will ever touch the barriers and will just drain down through the rock and into the drain pipe. On the interior walls (situated under the house) where there is close to zero surface water, there is MiraDRAIN over the black snot and then a filter fabric over that and dirt fill. At the bottom of the root cellar walls, drain pipe gravity drains to the street. That all sounds very simple, but getting the finished floor grades and header clearances right took a bit of detailed planning and execution!




"Black Snot"


Looking ahead, one of the issues to consider with Durisol is that is that the cells are closed and therefore need to be threaded over the steel rebar. However high the rebar is, that is how high the block must be lifted and lowered into place. Therefore, vertical rebar lap length is an important consideration with regard to labor. The building code has a safety factor; the structural engineers generally apply more safety; then, the contractor applies even more as a practical matter for inspections. Either minimize lap lengths without compromising structural integrity, or plan for the extra labor to stack blocks. I plan to write later about my thoughts on sustainable building (resource optimization) in the economic and regulatory environment and architect/engineer/legal culture I am building in. This issue is a form of waste that needs to be addressed in that context.

The time lapse camera got adjusted by (I suspect) some squirrels, so it is down and I am looking for a new place to mount it.


Monday, August 16, 2010

Construction status (foundations, sewer, time-lapse)

Last week some new workers arrived on the scene and the foundation forms and steel re-bar filled the basement and garage T footings.





The sewer was also trenched and installed through the site......not the most glamorous but still great stuff...

The site is getting very tight for space with two tractors and the eight to ten foot swath around the perimeter taken up by the top soil.  There isn't much space for the drawing table and crew to drop their things and take a break except under one of oak trees, a space forbidden by the city for occupancy during construction.





Below is a sample from the time lapse camera mentioned in an earlier post.  I will likely either put up another camera or find a better location as the house starts to go vertical.




The basement is in the rear left and the master bedroom pad is in the lower left third of the view.  The garage pad/foundation is not visible in the time lapse.  Note the blue wheelbarrow being filled and emptied with cleaned bricks.

Sunday, August 8, 2010

Construction status (offsite, site prep, grading)

Water and sewer laterals, and demolition of sheds, trees and shrubs, misc masonry and pipes are complete. Then, the more lengthy process of clearing out minor debris (a lot of small roots and other bits) to get down to clean top soil and ready for grading.

In the masonry that was demolished were some bricks from a barbecue, brick columns holding up a shed, pavers and some brick curbs around what was a lawn and other landscaping. The bricks include some "regular ones" and some “klinkers” which we are separating and cleaning off the cement for use on the exterior of the house and landscaping. 


This is turning out to be a lot of work but we are determined to rescue these gems and work them into the house and/or landscaping, something our architects were reluctant to do during design.

We moved the foot or so of top soil off to the side of the site. This serves two purposes: it preserves the more fertile top soil for the planting areas outside the building pad, and exposes the underlying layers of various densities of clayey sand to build on.  This underlying material is much more appropriate for supporting the foundation and concrete slab according to the contractor.  We rented a compactor and spent the last week forming pads, wetting down and compacting them to the final pad elevations.




That is Joe Ponte, our very competent excavation contractor, on the front loader and his employee Enrico on the vibrating compactor.  The red clay and the dark brown top soil are distinctive.  Donner, our dog, had a funny look on his face as the ground shook but surprisingly did not panic!  When the machine was turned off, he approached sheepishly sniffing in as much air as he could take without passing out.

As a sidebar, there is now available a very affordable time lapse camera full of features in a weather proof case.
http://www.wingscapes.com/catalog.aspx?catid=birdcameras ($62 at Amazon delivered!)

I’ll put up a sample of what the camera will provide in a later post. Early results are a little disappointing. I like everything about the camera except for the optics. I guess there wasn’t much left in the budget in a $62 camera after the weather proof case, electronics, packaging, laser pointer and mounting hardware!

Here is a picture of some guy wetting down the basement/root cellar in preparation for forms and concrete in the next few days.



Keeping the earth moist up until pouring concrete both controls the dust for the sake of my neighbors and will help provide a better curing environment for the concrete.  I took advantage of every opportunity to avoid concrete (and plaster) cracking, both of which are inevitable yet can be minimized through care and planning.  I am off to go and wet everything down again now......

Thursday, July 29, 2010

Harvey's Pleasanton Home introduction

In writing about this new home project, I am aiming for three audiences:

1. New home owners/builders/architects to document the lessons learned in the planning and construction of this "green" home.

2. Family and friends who may be interested in following the progress.

3. For myself as a record.

so that's my excuse for the dry tone.....


We purchased an infill lot in an established downtown neighborhood with the intention of building a home that would better suit our sensibilities about sustainable living and comfort in the empty nester years ahead.

The basic direction given to the architects included:
  • craftsman/arts and crafts architecture
  • site orientation for solar energy exposure
  • long lasting materials and building methods - think 500+ years
  • use wood sparingly - reclaimed or "sustainable" harvested product
  • solar hot water and PV's
  • landscaping - no grass - fruit trees, veg garden and mostly local native or Mediterranean plants
  • rain water collection for irrigation
  • second unit

After about 1 year of design, the following basic construction materials and methods were defined:
  • Durisol exterior walls - cement/wood fiber ICF (later changed to Faswall by Shelterworks in Oregon - http://www.faswall.com/ - more on that change later in the blog)
  • plaster on Durisol inside and out (more on this later)
  • SIP roof system
  • solar hot water and photovoltaic panels
  • hydronic heat in concrete slab first and second floor
  • finished/stained concrete floors
  • no AC - depends on insulation, thermal mass, site orientation
  • metal shingle roof http://www.custombiltmetals.com/
  • wood windows w/ metal clad exterior
The home is a two story design on a corner lot with the master and an office downstairs, one bedroom upstairs and a one bedroom apartment also upstairs (separate entry but connected inside).  The two car garage is separate with the driveway around the corner from the front entry.  The lot is about 11Ksf, approximately square with a gradual 6 foot slope from one end to the other.

The lot was split off from a property containing a 100yr old house and separate cottage in 2005.  Although there have been accessory structures (carport, shed, green house) on the lot over the years, there is no record of there ever being a house.

There are two mature oak trees (live oak and valley oak) at either end of the lot and one remaining (were 3) liquid amber near what will be the front entry.  The oak trees are not only beautiful, but play an important role in providing shade.

Wednesday, July 28, 2010

Harvey's Pleasanton Home

Architect: Siegel & Strain http://www.siegelstrain.com/
Landscape Design: Rebecca Coffman http://www.rebeccacoffman.com/