Construction status (more walls)

There's not much more to add at this point but photos of the walls.  They continue to get taller and are still straight as can be!  The second pour is a couple of days out.



Nacho lifting block over rebar



bending steel to allign with blocks.  This
is a junction of Faswall to CMU block
wall from basement



Ponch on entry wall

bedroom wing
(single story)

living room and bedroom wing from backyard
walls are at about 10ft

Construction status (Faswall walls, electrical)

Faswall blocks arrived!
Blocks are 85% wood chips (ground up old pallets)
and 15% portland cement and fly ash

The orginal plans were developed with Durisol ICF blocks, available in multiple widths. The first floor used 12" and the second floor stepped down to 10" with the relief showing on the exterior at the transition from plaster to board and batten siding.  This stepped appearance was an architectural feature I was not eager to to ignore when the wall contractor began seriously proposing a change from Durisol to Faswall.  Faswall is only available in 12" width.


The two products are similar in composition and less so dimensionally, but still generally compatible products.  Faswall is 8" tall where Durisol is 12".  Horizontal steal is placed at 16" intervals with Faswall (every other course) and at 12" minimum intervals with Durisol.  This meant the structural engineer needed to do some work to establish a revised steal schedule.  Further, I needed to be convinced that the 12" block all the way up would have an acceptable appearance at the transition from plaster to board and batten. Some mock-ups were built and, while I believe the stepped transition would look better, the benefits in switching to Faswall had a greater influence on the decision to make the change.  The primary benefits are that Faswall (by Shelterworks) were far more forthcoming with information and technical support, and the manufacturing plant is located in Philomath Oregon (575mi) vs. Ontario Canada (2,600mi).  Everywhere else where <12" wide blocks were defined, the appropriate CMU block was used instead.

Corner window showing mineral wool
insulation and excellent fit!

View from office looking at house to the NW

I've been very pleased so far with the ease of assembly and cutting blocks to form a straight and true wall.  The workers, who are skilled in carpentry and to a lesser extend masonry, seem to work with the new construction method with ease.  Even the electrician, who is more accustomed to rolling in on the job after the wood framed walls are up and running wire and attaching junction boxes most anywhere, is positive about working in the somewhat more constrained environment.  With only a couple of minor exceptions which can be repaired such that we'll never know the difference, the electrical boxes have been installed very cleanly and tight in the Faswall blocks. Of course, we do not have the luxury of no/poor planning with regard to the locations of electrical outlets and switches that we would have had with wood framing.  We have to get it very close to right out of the gate which doesn't seem to be a very difficult.  If we find we want to add or move something after the concrete is poured, we have somewhat limited ability in routing new wires or we'll just have to live with it.  Afterall, keeping things simple is part of what we are trying to acheive in our lifestyle goals and fewer recepticals/switches means less material and waste.



Kitchen wall with electrical boxes

It looks like we are about a week away from pouring the first lift of concrete in the walls.  The wall contractor does not anticipate using any bracing and intends to rely on the glue, a few deck screws that are holding the blocks in position, and careful management of the concrete pump/hose to yeild straight walls.





Construction status (slabs, cistern)

Pandeck over basement

October through December were full of form building, in-slab plumbing and electrical, steel (rebar, red iron, pandeck), grading, underground cistern, and a few rain delays.  The Fawall block walls starting going in today (1/3/11) so I have some things to catch up on before reporting on the external wall phase.

My favorite part of the project thus far has been the design and construction of the storm water cistern. During the design phase, rain water storage kept getting put off until finally laid to rest as a rectangular shaped dotted line on the landscape plan. Since this was an essential component of our sustainability objectives and had to be built early in construction, I researched various storage methods including material and construction costs with the following requirements:

• 5000 gal minimum
• Underground
• Pump suitable for drip/micro irrigation (minimum 10 gpm @ 20psi)
• $5000 budget ($1/gal)

I found several suppliers of plastic underground tanks maxing out at 2500 gal and larger fiberglass tanks. These were the most intriguing underground plastic tanks:

• Conservation Technology 2500 Gallon Double Torus www.conservationtechnology.com/rainwater_storage.htm

• Norwesco 2500 Gallon Below Ground Holding Tank www.tank-depot.com/productdetails.aspx?part=TN2500WT

Fiberglass tanks in 5000 gal size cost approximately $7000 and the 2500 plastic tanks are in the range of $2300-3500 each plus shipping ($671 for two Norwesco tanks). We also looked into precast concrete vaults which cost around $8000. The Norwesco tank appeared to be the most economical "off the shelf" solution at $2300 per tank. Other costs to consider for water storage are excavation, backfill and piping between tanks if needed.

My contractor convinced me he could build a concrete tank for less than the cost of the plastic tanks. The plastic tanks have limitations in how deep they can or must be buried and their dimensions may not work efficiently in the space available.

Purely looking at cost per gal of the storage container (w/o shipping), it breaks down approximately like this:

• Norwesco 2500 gal - $1/gal
• Double Torus 2500 gal - $1.50/gal
• Fiberglass 5000 gal - $1.50/gal

I was preparing to order Norwesco tanks when my contractor suggested building a steel reinforced concrete cistern. The idea was to build a tank using 4'x8' plywood forms on the inside and earth as the outside form. This also meant the tank could be any rectilinear shape desired, a big plus in our situation due to space constraints.  The area we were considering for the tank lies between the garage and root zone of a large Valley Oak tree. We decided to construct the tank in an "L" shape around the end of the garage and about 6" to 18" underground. This will conform around the garage and not encroach on the root zone or very far into the backyard planting area. The finished inside tank dimensions worked out to be 8'W x 4'H x 14'L on each leg of the "L" or effectively 8x4x36=1152cf=8,559gal.







Add a fiberglass 24" manway for $300 delivered from (www.frpsupply.com), PVC sleeves for the inlet and outlet and you have a nice sturdy underground water storage solution. The 2x4 and plywood forms were removed 10 days later through this manway.  I will report on the total cost breakdown once all of the numbers are in. So far, it is not looking as good as originally expected but likely still lower $/gal and more efficient site utilization.

Rain can be collected at a theoretical maximum rate of 620gal per 1000sf of horizontal roof per inch of rain. However, there are losses in the collection process (splashing, leaks, filtration losses) so I will derate by 20%.

An appropriate pump for this application is a "Shallow well jet pump" which consists of a jet pump and a pressure tank. This type of pump is capable of lifting water 0-25 ft and filling a pressure tank. Water is "demanded" from the pressure tank for use and refilled by the pump as required. Pumps and tanks for our specifications run about $300-$400. I will likely go with a packaged pump/tank system like a Sears Craftsman Professional 1/2 hp Shallow Well Pre-Plumbed System (8 gmp @ 40 psi).

The  roof collection area is approximately 1500-2000sf. Water will flow into rain gutters, through downspouts and exhaust in two or more vessels. The vessels are intended to be both decorative and functional as sand filters. Pipes under the vessels will carry the water through another secondary filter(s) and into the cistern. There are a few items yet to consider including venting, biological water treatment, overflow and water level monitoring.

At the time the top of the cistern was poured, the remaining sub slabs of the house and remaining CMU block walls were also being poured. The finish slabs which contain the plastic PEX tubing and form the finished floor will be poured much later in the project after the heavy construction traffic subsides.

Justin vibrating CMU wall



 

  

living room slab pour / entry coat closet opening





Around the slabs the plans called for 2in of rigid foam insulation. The contractor and city inspector were uncomfortable with the slab not tying into the foundation perimeter. A compromise was agreed to such that the insulation began directly above the connections of the steel anchors from the slab to the perimeter concrete. The first 7 or so inches of slab is insulated which should substantially reduce the thermal path from the topping slab (hydronic heat) to the perimeter foundation to earth.

Faswall was qualified as an alternate source for the exterior block walls (www.faswall.com) and was delivered this week. More on the Durisol to Faswall substitution in the next update….

 

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.

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.

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......

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.