Tuesday, September 27, 2016

Construction - Back to Dirt Work - The Insulation/Watershed Umbrella

As much as I would have liked to have continued with the carpentry phase of construction, the reality was that it was mid-September and we had only a few weeks to finalize the grade in front of the house and get it planted with a cover crop to control erosion during the rainy season next Spring.  Consequently, with the internal bearing walls in place, it was time to shift our attention to more dirt work.

The main job was to get the insulation/waterhed umbrella installed.  (Click on the "Featured Post" feature in the left column for linkage to Annualized GeoSolar and the role of the umbrella.)  However, loose ends had to be taken care of first.  The porch foundation had to be insulated and clad in the manner described for the east garage wall.  The exterior of the insulated concrete forms for the house foundation wall had already been covered with cement board but still had to be parged with stucco.  The grade needed tweeking before the umbrella was installed.  The umbrella needed to be laid down and covered with topsoil and the topsoil needed to be blended with the grade further down the hill in front of the house.  Finally, the cover crop needed to be planted no latter than mid-October.  Oh, boy! The race was on.

Insulation for the porch foundation; the footing extends
below the insulation and will be insulated eventually with
more foam board laid horizontally
Insulating the Porch Foundation
Cement board over the insulation
The foundation for the screened porch needed to be insulated in order for it to meet code as a frost-protected shallow foundation.  The porch floor was intentionally poured 3 1/2" wider than the foundation wall on all sides in order to accomodate 2 1/2" of foam insulation and +/- 1" of cement board parged with stucco. For details on the DIY insulation for concrete walls, check out a prior post.  In addition to vertical insulation for the wall, horizontal insulation laying on the footing and extending out 2' on the three sides that are not part of the umbrella is necessary to complete the frost-proofing.  It will be installed in conjunction with final backfilling against the porch foundation before winter sets in.

Stuccoing the Foundation
The house foundation was insulated automatically by using insulated concrete forms but
Stepson, Keith parging the cement board with stucco

Friend, Roger, parging the cement board that covers the insulated
 concrete form
needed to be veneered for appearance-sake and to protect the foam from damage.  Again, I used 1/2" cement board. The next task was to stucco the cement board on the porch and house foundations in exactly the same manner as described in the prior post. The stucco serves two purposes.  It improves the appearance of the top part of the foundation visible above grade and it seals the cracks between the cement board panels against freeze-thaw damage.

Insulation/Watershed Umbrella
The grade for the umbrella was largely done months earlier with the track loader but had been overtaken with grass and weeds that I did not attempt to combat because they controlled erosion.  Now it was a matter of using the trackloader blade, tipped up as a scraper, to remove the vegetation then spending a couple of days tweeking the exposed dirt with hand tools to be sure the insulation met the foundation footing correctly, the soil surface on which the umbrella would lay was as smooth as possible and that the entire area would drain properly.
The grade after removal of vegetation with the track loader
and tweeking with hand tools; notice that the dirt is still not
smooth enough to protect the plastic sheeting from puncture

Parenthetically, parts of the umbrella were already in place.  The insulated and impervious garage and screened porch floors comprise most of the umbrella on the east side of the house. I will install the rest of the umbrella on the east next year before the concrete walkway to the main entrance and the driveway are placed over it.

Building the Umbrella
The umbrella consists of ten layers as follows, starting from the grade and moving up through the umbrella:

Sand / 6 mil plastic sheeting / foam insulation board / sand / 6 mil plastic sheeting / sand / 6 mil plastic sheeting / sand / two layers of recycled carpet laid upside down / topsoil.

This configuration for the umbrella deviates only slightly from the one John Hiat describes in his book, Passive Annual Heat Storage, primarily by virtue of our liberal use of sand.  I will discussing the first three layers of the umbrella in this post and the last seven layers in the next post.

SAND
Two-inch thick sand layer over the raw soil to protect the
overlying plastic sheeting
Fortunately, I was able to enlist the help of step-son, Keith, and our friend, Roger, for the installation, which would have been extremely arduous for me working alone after having just done the dirt phase alone.

The dirt surface, despite all of the hand work, was too rough on which to lay the first layer of plastic sheeting without worrying it being compromised when loaded.  So we covered it with +/- 2" of clean sand.  I could bring the sand only to the periphery of the umbrella with the loader so we had to use wheel barrows to distribute it.  We found that a push broom, used mostly upside down, to be the most useful tool for spreading and leveling the sand.  

PLASTIC SHEETING
First layer of plastic sheeting with foam board on it
to help hold the top edge in place as it is stretched out
The best buy on 6 mil sheet plastic that I could find was at a farm and home center in the form of a 24' x 100' roll which was only a little more than what we needed for each layer of plastic going into the umbrella.  We cut and laid the first layer of sheeting over the sand base.  I previously had left two layers of plastic sheeting hanging out under the cement board/stucco covering for the house foundation and from under the rock retaining wall to the west of the house that needed to be woven into the sheeting of the umbrella. The first overlapped in shingle fashion the edge of the first umbrella sheet.

FOAM INSULATION
Most of the umbrella extends 16' feet from the house (20' would have been better but the
Most of the foam board in place and anchored for the night
placement of the solar collector and the under-dug embankment west of the house changed the rules). So the pattern for the foam insulation, based on Hiatt's prescription, was as follows:  4" thick for the first 8', 3" thick for the next 4', 2' thick out to the 16' periphery.  And in the few places the full 20' was possible, 2" thick for the last 4' (Hiatt recommended 1" but a sheet that thin at the periphery could be crushed too easily).


Balance of the foam in place; notice that the weaker white EPS
board in the first tier has been covered with the stronger XPS
 board in the second tier
In all, it took 70 sheets of 2" board, 20 sheets of 1" board -- all laid as much as possible so that the cracks between sheets in the first layer did not line up with the cracks in the second layer. Expanded polyethylene (white board in the pictures) is half the cost of extruded polyethylene (blue board) so about 40% of the 2" boards were EPS installed under the more rigid and relatively crush-proof  XPS.

Part of the hand work for the grade preparation was to make sure the first 2" layer of foam board butted up against the footing and was flush with the top of the footing.  In this way, the second layer rested on the footing and against the foundation wall so as to fulfill the requirements of a frost-protected shallow foundation. As mentioned above, the cement board/stucco cladding for the foundation wall was backed by two layers of plastic sheeting that stuck out quite a ways at the bottom.  The innermost layer overlapped in shingle fashion the plastic sheeting that laid directly on the sand bed.  As we will see in the next post, the outermost layer overlaps the top layer of the umbrella plastic.  The loose ends of plastic sticking out from under the stone retaining wall were handled in the same way.

Saturday, September 17, 2016

Design - Photovoltaic Array

Not "If" but "When"?
If we install photovoltaic cells, our electric company will allow us to use reverse metering to export electricity to the grid when we produce more than we consume. Unfortunately, unless the rules change, we will be credited at a lower figure when exporting (meter running backwards) than what we will pay for electricity when importing (meter running forwards).   Our goal is to break even with the power company without over-spending on photovoltaics but we won't know until we live in the house for awhile what it will take to do so.  Then we can size the photovoltaic array to our needs or perhaps decide that the return on investment for an array would be problematic.

Other Advantages of Waiting
In addition to monitoring our needs before investing in solar, there are other advantages to waiting.  Solar prices keep coming down and the panels almost certainly will be cheaper in the near future.  Utility company rebates and government rebates and tax credits come and go but I think the probability of this kind of help may actually increase over time pending which political party dominates at the federal and state levels.

Disadvantages of Waiting
Installing the panels initially would afford the opportunity of having them double as an
overhang for the second level clerestory windows, as shown on the accompanying
Click on drawing for expanded view
drawing, and thereby eliminate the cost of a conventional overhang.  The conduits and wiring from the array to the service panel would become part of construction instead of an afterthought.  However, we are more inclined to delay construction of the overhang for a couple of years anyhow in order to use the heat from the summer sun to jump-start the AGS system. Moreover, in order to function as a overhang for our latitude, the tilt of the PV panels would likely not be optimal for generating electricity.

Compromise Plan
We will probably decide to wait at least a year before investing in PV panels.
Instead of using the panels as an overhang for the second story clerestory windows, they will probably take the form of a free-standing array on the backfill behind the house that will be an easy electric hook-up and will be scarcely noticeable from the street. Free-standing, as opposed to attached, could include an upgrade to a mobile sun-tracking system to maximize solar gain.

Estimating Needs
The average rate-payer in the St Louis region uses 10,000 to 13,000 kilowatt hours per year, depending on whose figures one uses.  The 13,000 figure is about the average for the country as a whole.  The modern rental house in which we lived when first moving to Collinsville would be a better barometer of our electric usage than the 100-year-old farmhouse that we have since bought and occupy next door to the construction site. The rental unit had HVAC, electric range and electric dryer as the main demands on electricity.  We consumed 6,400 KwH/yr which is not much more than half the area-wide average, due in part to our sustainable-centric lifestyle and the reasonable size of the house.

Based on our experience in the rental unit, we are guestimating our electric needs in an energy neutral home to be 1,600 KwH/yr despite it being a larger house.  The load will be diminished, compared to the rental unit, by the intentional design of the house. Gas will be the choice for cooking and heating water (energy efficient tankless heater).  There will be no conventional electricity-scarfing air conditioning.  Abundant natural light in all spaces will minimize the use of lights during the daytime.  Most of the lighting will be task lighting.  General lighting will be controlled by manual override, dimmable motion activated switches so as to match use with occupancy. Energy-saving LED will prevail over CFL. Phantom loads will be minimized via strategic switching, not just for electronic equipment, but for mundane appliances like the toaster, microwave and clothes washer.  

Return on Investment
If an average consumer at 10,000 - 13,000 KwH/yr were to buy PV with enough capacity to make some dent in his/her energy consumption (forget about breaking even with the utility) the initial cost would be dependent upon how big a dent s/he wanted to make.  But the return on investment from energy savings would be protracted because her/his home was probably not designed for serious energy conservation.  My take is that adding PV to the average production home with 2 x 4 walls, or even 2 x 6 walls, and questionable attention to air-sealing, or to older homes like ours with no wall insulation, homes with solid masonry construction or homes with leaky windows and doors is like rearranging the deck furniture on the Titanic.

As counter-intuitive as it may be, PV for our super-insulated, passive solar project may not be a good investment.  Our consumption will be so low that the payback on a PV system that breaks even with the utility may not make sense.  On the other hand, it might.  The decision to invest in enough solar to be energy neutral might have less to do with cost-savings now as it does with insulating us from escalating energy prices in the future. If we add PV, it will be with the conviction that, with the current and future pressure on fossil fuel energy, the cost of electricity will only go up.

Thursday, September 8, 2016

Construction - Second Line of Interior Bearing Walls

As explained in the previous post, it made sense to erect the interior bearing walls before starting the exterior walls.  Accordingly, that post went on to describe the first bearing wall -- situated a few feet inside the concrete earth-contact north wall.

This post details the second east-west line of structures, more or less in the middle of the house, that will support the front wall of the second story and the roof above it. This line is 55' long and comprises a complicated combination of a 2 x 4 wall, 15" thick truss wall, a header and a post and beam span over the living room-dining room-kitchen open floor plan.

(For a better understanding, it might help to consult the architectural drawings.  Click on them, as well as on photos here, for exploded views.)

Central Bearing Walls
The central bearing wall nearly complete; truss wall in foreground, post &
beam section in the middle; bathroom framing next and a dual header last
The south wall of the bathroom area comprises the 2 x 4 bearing wall section. Consequently, my first task was to build out the bathroom framing, including the joists that form the ceiling for the bathrooms and the floor for the second floor balcony office. The second story exterior wall will rest on the sub-floor on top of the joists.
Another view of the central bearing wall for better visualization of the
bathroom framing and the dual header to the left

Next, I had to build the north wall of the laundry area and a short section of the exterior truss wall extending east of it -- the section that will house the main entry eventually. Unfortunately, the wall contained pre-made wall trusses with plywood gussets that needed to stay dry and an imminent threat of rain caused me to wrap this section of wall in plastic before taking any photos.  Just as in the bathroom area, the second floor exterior wall will sit on the subfloor of the second story bedroom. Consequently, I had to install floor joists and
The subfloor on which the second story exterior wall will rest; the
narrow isthmus comprises the catwalk between the balcony office
in the foreground and the bedroom in the distance 
tie them into the front wall after it was under the plastic.


Catwalk
The second story exterior wall will also rest on the subfloor of the catwalk that bridges between the two second story rooms and extends westward over the master bedroom. The bridge portion of the catwalk is supported by two beams.  The short section of the catwalk that will overlook the bedroom will be supported by a combination of a header, a joist and a beam.  None of the catwalk could be built until all of the
Pre-made wall sections under cover
beams were in place.  Early on, the pre-made wall sections for the windows were stored under plastic in the master bedroom area.  Now they are in the way of completing the west end of the catwalk. I plan immediately to call in volunteers and lift most of them to the new second story for use in the south exterior wall. Then the remainder of the catwalk can be framed and subfloored to complete the central bearing wall.


Post and Beam Section
When designing the house, my fondest dream was to use salvaged barn timbers for the post and beam supports.  And my step-son and I were able to salvage a few good timbers and many not-so-good timbers from a 19th century barn.  We used the better ones for his house several years ago and the rest would be unsuitable for our needs.  So, in the interest of time and probably money (salvaged timbers can be pricey), I decided to scrap
Friends and family volunteers installing the heavier beam
the barn timber idea in favor of the man-made variety of which there were two options.


The plans called for 3 LVL's (laminated veneer lumber) fastened together to make the main beam.  They do not come in "appearance grade", meaning they are not pretty enough for a natural finish look and must be hidden behind something like drywall. An alternative was Glulams, another man-made product.  A natural finish on them became moot when the manufacture recently quit offering the option of a clean product with no identification information stamped on it.  To use them would involve much sanding to erase the markings for a natural look that even then would have been marginal at best.  The plans called for two sizes of beams. For the larger one, a Glulam beam would cost 28% more than an LVL's; for the smaller, a Glulam would cost 32% more than LVL's.

The posts specified by the drawings were 6 x 6s and the options at my lumberyard were pressure treated yellow pine, cedar and kiln-dried pine.  I chose the latter for a several reasons.  Pressure treated posts were unnecessary, more expensive than the pine and more likely to warp. Cedar, although it could have a natural finish, would not fit in with the other natural woods used in the house and it would be twice as expensive as pine.  The disadvantage of pine is that its natural look does not fit well either and will therefore need a drywall covering.  The robust hardware used to join the post and beams is anything but aesthetic and is best hidden behind drywall as well.   

Beam Construction
For bridging the 20+ foot gap between the bathrooms and the laundry area there needed to be two beams -- the "main" beam, to carry the second story wall and the "catwalk" beam, to carry the north edge of the catwalk.  The plans called for three 1 3/4" thick LVLs fastened together for the main beam supported on posts at both ends and one post midway.  Two LVLs were specified for the catwalk beam with no intervening posts.  

According to information online, the LVLs could be fastened together with through-and-through bolts, with construction screws or could be nailed together with 3 1/2" nails.  For
expediency and to save costs, I chose nails.  The longest nail my Paslode framer shoots is 3 1/4" which is just long enough for fastening 1 3/4" thick LVLs back-to-back.  The nailing pattern for a 12" tall beam was as follows:  Either two or three rows of nails (I chose three) with the nails in each row no further apart than 12" and no closer to the edge of the boards than 2".  Furthermore, the nails in each row should be driven from both sides so that the nails on a given side would be 24" apart in an alternating pattern with the opposite side.   In the case of the main beam that involved three LVLs, I nailed two together 24" OC then flipped them over, laid on another LVL and nailed it in an alternating 24" OC pattern.  The photo shows clamps to align the LVL's for nailing and the chalk lines guiding nail placement.

Despite manufacturer-applied "weatherization", I doubt that the integrity of the LVLs -- much like other manufactured wood products like plywood and OSB -- would hold up under my snail-like construction schedule that postpones getting them under cover for several months.  Therefore, my intention was to caulk any cracks and openings on the topside then paint them with Kilz undercoated in order to buy some extra time.  However, only the larger beam got painted; before I could l paint the smaller beam, we had the subfloor installed and I am assuming that its 500 hour rating against the weather will protect the beam sufficiently.  I do not regret having painted the larger beam because it is more vulnerable to sideways rain coming from the southwest and southeast.

Post and Beam Hardware
The hardware needed to join the posts with the beams was simplified by having beams long enough to span the entire 20' distance.  All that was required were off-the-shelf post bases to anchor the posts to the floor and keep them from touching the concrete and "T" braces (stand-alone post) and "L" braces (end posts) to secure the posts to the beams. The braces were pretty robust -- 1/4" thick -- and were fastened with the substantial 1/4 x 2 1/2" hex screws that came with the braces.

Saturday, August 20, 2016

Construction - Carpentery Phase Begins with Interior Bearing Walls

Now that most of the dirt and concrete work are behind us, the carpentry work can begin in earnest.  However, some "infrastructure" work needed to be done first.

"Infrastructure" First
The carpentry phase of the project will take quite a while since I will be working alone most of the time and working alone is several multiples slower than twice the time of two workers or three times the time of three workers.  So, it makes sense for me to acknowledge the situation and spend as much time as necessary upfront to shorten and simplify the process downstream.  

Consequently, I used a couple of substantial steel desks that I "inherited" to create a sawing station.  I secured the compound miter saw to them well enough that stealing it would be too much trouble. By covering it with a tote to protect it from the weather, it can be left in place indefinitely.  I created a way to lock the abundance of the drawers in the desks in one fell swoop so as to be able to store tools and supplies on site.  Instead of installing temporary electric service and incurring a minimum per-month-charge for a meter, I ran a 10 ga extension cord from my workshop next door high enough overhead to be safe from tall vehicles.  I made provisions for locking the ladders under a cover.  And, as will be discussed below, I spent lots of time simply building a safe scaffold that will stay in place until after the drywall that can be reached from it is hung, taped and painted.

Sequencing Wall Construction
A must read for anyone doing construction alone
I made the decision to reverse the order of wall construction over what a professional builder would likely do, viz., I am building the interior bearing walls ahead of the exterior walls. The exterior walls will be constructed from shop-built  wall trusses and window-housing wall sections that have plywood and OSB elements that would not survive prolonged exposure to wet weather. Consequently, they will need to be roofed over as soon as possible after being raised. By contrast, the interior bearing walls will have no plywood or OSB so will be more able to handle some rain while I raise the exterior walls and construct the roof. Accordingly, I began with the most interior of the interior walls -- a tall wall that parallels the north concrete wall -- and, in conjunction with it, the scaffold.  It is mid-August and we are entering what is usually a drier season.  I am hoping to erect the exterior walls and get the roof in place before the Spring rains start.

The Long and Tall Bearing Wall
The first wall is 56' long, 16' tall and parallels and stands 5' away from the north concrete wall.  Eventually, it will divide the living space from the storage area (see the architectural drawings).  Four of us raised it in three sections that I tied togetherlater via 2 x 12 headers and, for a short section, the second component of a double top plate.  The fourth section (last photo below) was added subsequently with the help of volunteers.

Since the wall is so tall, scaffolding was necessary early on for joining the wall sections with a top plate or headers. The scaffolding will also be necessary later for adding a short truss wall to the top of the concrete wall and for setting the roof rafters.  And, as mentioned above, It will stay in place until the dry-walling and painting above it are done.  I suspended the scaffold between the two walls flush with the top of the 12' concrete wall. Not only does it serve as a work surface, it also holds the tall wall plumb until it can be tied to the roof.  As you can see in the pictures, the scaffold framing is all salvaged lumber and the plywood deck has been weatherized with stain so it can be reused later.
Above left photo:  interior view of scaffold.  Right photo:  exterior
view of scaffold; notice stationary ladder and the rope from the 
pulley hanging from the guard rail that runs to a box below
 for raising tools and supplies to the scaffold

It takes only a glance at the wall framing to appreciate the challenge of installing the three double 2 x 12 headers after the wall was raised while working alone, especially the one at the 16' height. I was able to do it primarily from reading John Carroll's "Working Alone". His individual methods come in handy but its major impact is the way it fosters a different way of looking at construction that makes the seemingly impossible quite possible.  It would have been a real challenge to have assembled the headers on the floor then attempt to raise them by myself. So I raised the pieces for each header separately, which in itself was a bit of a challenge for the higher headers, and assembled them in place -- without Carroll's influence I probably would have been calling for volunteers and waiting until they were free.

The long low header to the right in the photo below bridges over the numerous stubbed-out ends of the PEX water supply lines that run separately to each faucet in the kitchen, bath and laundry (home-run configuration).  They emerge from the concrete just barely behind the wall but the temporary bracing that holds them in place now would interfere with raising the wall in front of them.  The header allows me to postpone piecing together the bottom of the wall until the bracing is removed.

Salvaged Lumber Situation

As you can tell by the color of the lumber in the tall wall, most is new.  There were not many salvaged 2 x 4s long enough and straight enough for the job.  Pre-building the wall trusses over the past couple of winters consumed most of the salvaged 2 x 4s that were in the eight-foot range and the section of the tall wall being installed in the photo below used the few that were longer.  My current inventory of salvaged 2 x 4s is mostly boards that are less than 8' but will work or can be made to work, for most of the other interior walls. Ultimately, I do not expect to have to buy many new studs.  As for the 2 x 6 walls, there will be enough salvage for all of them.
Frontal view of the wall after the section being raised in the next photo is in place;
the headers to the left are in association with a second story room that protrudes
 through the wall; the header to the right bridges across the termination of a 
dozen or more PEX water supply lines
(as with all the photos, clicking on the pic will enlarge it for better viewing)
Design of the Tall Wall
Initially after raising the wall, there were two large openings above substantial headers. As can be seen in the fourth photo, the opening to the left is to accomodate a second story balcony-like office that will cantilever through and extend 2' beyond the tall wall. Before the the photo was taken, the other opening to the right of the wall above the header that is just over the PEX plumbing rough-ins (under the burlap). The fifth photo shows the fourth and last section going in over the 
The fourth section goes up with two of us pulling from  the scaffold
plumbing with the help of friends and family.  

The Next Line of Bearing Walls
Actually, the next line of east-west "bearing walls" that are slated for the middle of the house, comprise as many post-supported beams as stick-built walls due to the open floor plan in the dining room/kitchen/living room area.  These mid-line bearing structures will support  the second story south wall and the catwalk just inside of it but not alone -- the floor framing for two second story rooms plays a role as well.  All this will be covered in the next post.

Friday, August 12, 2016

Design - Final Architectural Drawings


Perspective
I have deliberately withheld the architectural drawings until now (the 84th post to the blog) because most of the dirt work and concrete work, except for that pertaining to the AGS system*, is pretty generic for any slab-on-grade house and the drawings would not have added much value.  The atypical dirt and concrete work for the AGS system*, although definitely unique, was only loosely influenced by the floor plan. But, now that we are ready to start building vertically with wood, the architectural drawings may perhaps be of interest.  

The drawings lack the finite details that are typical of most construction projects. The design is mine so the drawings were mostly a matter of professionalizing my amateur drawings so the structural engineer would stamp them and the Building Director would accept them.  Not only was the Building Director comfortable with letting me sweat the details, he encouraged me not to pay additional architectural fees for more detailed plans. Because we had already had 5+ years of collaboration on the project, he was also willing to trust me to make changes without checking with him first. 

(For a blow-up view of any drawing, click on it or click on the first drawing to blow it up then scroll down through the rest of the drawings.)

Design Summary
The house is nestled into a 15 degree slope so as to have the right amount of earth contact and it faces south so as to benefit from the sun's energy for passive solar heating and air conditioning via a system called Annualized GeoSolar*.  It would qualify as a two-bedroom, two-bath ranch except it has two second-story rooms -- a third bedroom and an office.  As is typical with passive solar homes, the house is longer east and west than north and south -- by a factor of 2:1. It has earth contact with nearly all of the two-story north wall, half of the west wall and with a slab-on-grade floor. All but three small windows face south but, by virtue of clerestory windows, there are no rooms without dedicated windows. The two-car garage is attached and is heated by the same AGS system as the house but to a lesser degree.  The "back door" into the kitchen leads in from the screened porch in front of the house. Except for the second story, the house exceeds compliance criteria for the American Disability Act.  

Page One
Page 1 contains two drawings showing the front and back of the house.  The top drawing
is useful for visualizing the screened porch and garage relative to the house and the abundance of south-facing windows for passive solar gain. This drawing and the one on page 5 shows a photo-voltaic array for generating electricity as well as serving as the overhang for the second story windows. This early idea was abandoned in favor of a site-built overhang and a free-standing, post-mounted array to the north of the house. Otherwise, we are adhering pretty closely to the drawings.

The second drawing shows the extent of backfill against the tall north concrete wall -- almost 12' above floor level in the center.  It also shows a short stick-built wall on top of the concrete.  The abrupt changes in elevation of the backfill represents the location of retaining walls running north.

Page Two
Page 2 shows the details for the footings, foundation, concrete walls and concrete slab. With regard to the tall north wall, the design shown here is not what the structural engineer accepted but what he designed and stamped was not what we did. With the blessing of the Building Director,  we poured a 10" thick wall, instead of 12", and used three deadmen and two right-angle west and east walls to brace it. We also poured a slab at least 5" thick and reinforced with fiberglass fibers instead of a 4" with steel mesh reinforcement as called for in the drawing.  Otherwise, we stayed with the drawing.

Page Three
Page 3 is the floor plan for the lower story. Here we are taking liberty with the drawing in the living space adjacent to the garage. The drawing shows a workshop north of an airlock. When we were able unexpectedly to buy the property next door to the building site and use it as our our temporary residence, I turned its large free-standing garage into a workshop which I will keep even after we convert the temporary residence to rental property. The workshop area in the plans then morphed into more living room space, a reconfigured airlock and more storage area. The DIY picture of the altered floor plan appears as the last photo below with my pencil drawing of the changes taped over the original drawing.  Otherwise, we are sticking to the plan.



Page Four
Page 4 shows the second story layout.  There is a balcony office over the bathrooms that looks out over the living room towards the east but not over the master bedroom on the west. There is an east-west catwalk cantilevered over the living room and master bedroom. Towards the east it connects a bedroom to the stairs and office and towards the west it extends out over the master bedroom. It serves three functions:  (1) it provides access to the second-story bedroom; (2) it provides access to the clearstory windows for opening and closing, washing and, perhaps someday, managing thermal shades and (3) it adds architectural interest. 

Page Five
Page 5 shows primarily the east and west profiles of the house and screened porch as well as a north-south cross-section at the level of the stairway.  

It brings dimension to the extraordinarily high ceilings in the living room and master bedroom -- 20' from the floor at the clerestory windows and 16' at the partition between living quarters and storage area. The high ceilings will allow light from the clerestories to reach the back of the living room and master bedroom. The drawings clearly show no windows on the west, three small ones on the east, two of which are in the garage, and the rest facing south.

Altered Floor Plan (Last Photo)
The workshop has been eliminated and its space reallocated to the living room and some to the storage area along the north wall.  The long dimension of the airlock was shifted 90 degrees for better utilization of the abandoned workshop space for the living room.
____________________

* For information on Annualized GeoSolar, click on the "Featured Post" in the left column above which is the the first of three posts on AGS.

Tuesday, August 2, 2016

Construction - Summary of the Dirt and Concrete Phase of Construction

Reminder:  A click on any photo enlarges it for closer inspection.  Also, for details on the phases of construction discussed below, click on the appropriate links to previous posts.

Broke Ground
We broke ground on August 3, 2014.  It took about a month's worth of track loader digging for me to rough out the excavation into the side of the hill --  a lot of trips up and
Pre-made French drains:  Wrapping perforated culvert
with specialized geo-textile fabric
down the hill to carry the dirt to storage behind and to the side of the building site.  Rain and cold weather pretty much put a stop to the dirt work leading up to and during the winter.  Meanwhile, I used the time away from the dig to fabricate French drains that were of custom design and to begin assembling exterior wall trusses in my workshop.


French Drains and Solar Collector
 Installing AGS conduit after the French drains were backfilled
April of '15 was an unusually dry month for April which allowed a excavation contractor to smooth and grade the footprint for the house. Then, as he dug trenches for the French drains,  a crew of volunteers snaked the long drains to the trenches and lowered them to place with ropes.  Once the trenches were backfilled, the contractor began trenching for the conduits for the AGS system* and dug the pit for the solar collector.  With the help of volunteers, the conduits were installed and backfilled just before a rainy May and early June.  Between frequent rains, I, with occasional help from friends and family, managed to get the solar collector built using dry-stacked concrete blocks parged with fiber-bonded cement. By mid-summer we had the conduits connected to the collector and associated backfilling done. 
Solar collector:  Notice pipes exiting the back wall that connect to the
conduits under the house which, in turn, connect with the pipes
running to daylight behind the house; when the collector is finished,
heat from the summer sun will course through the conduits and warm
the soil under the house; heat from the soil will conduct through the floor
 and the concrete back wall to condition the house in lieu of conventional HVAC


Footings, Concrete Walls and Shallow Frost-Proof Foundation
The concrete work was begun in late summer of '15 and barely completed before freezing
weather.  The contractor dug the trenches for footings to support the north and west concrete walls and
Concrete walls in place; shallow frost-protected foundation poured inside
of insulated concrete forms; waste plumbing roughed-in
 the foundation under the stick-built walls. I did what forming needed to be done for the wide footing for the concrete west and north walls and the contractor poured the footing then poured the wall.  With some help from volunteers, I formed up and poured the narrow footing for the foundation under the stick-built walls.  A friend and
 I erected the insulated concrete forms for the shallow frost-protected foundation over the narrow footing and several of us poured the foundation inside the forms.  All that remained of the concrete work were the floors for the house, garage and screened porch. However, they had to be put on hold until the electrical and plumbing rough-ins, situated below the floor, were done. 

Plumbing and Electrical Rough-Ins; Slab Floor; Partial Backfilling
By mid-October, I had the plumbing and electrical rough-ins ready for slinging the gravel sub-base and pouring the slab floor.  The contractor poured the floor but only for the house
Supply plumbing and electrical rough-ins done; gravel sub-base and
plastic sheeting in place; house slab in process
-- the garage and screened porch were put on hold.  A few weeks later, I damp-proofed the concrete walls and installed a footing French drain at the base of the walls and ran it to daylight in front of the house at both ends. Then I backfilled the north wall to about half its height and sloped the grade behind the house for efficient surface drainage in preparation for upcoming rainy weather and winter freezing.  As recommended by the concrete contractor, I coated the fresh slab with a sealant to prevent damage to the fresh concrete from freezing and covered the exposed footings with 2" EPS (styrofoam) for the same reason.  That was about all we could do towards construction until Spring so I turned my attention to several upgrades to the old farmhouse in which we live next to the building site.  Also I was able to finish building the wall trusses that we will need this summer for the exterior walls and to erect a temporary enclosure in which to store them.


Retaining Wall
West wall of the house insulated and partially parged with
stucco; retaining wall in place with insulation and two layers
of plastic behind and under it as part of the
insulation/watershed umbrella for the AGS system*;
partially backfilled
The first project for the early Spring of 2016, was building a retaining wall running west from the west concrete wall.  However, as part of the umbrella for the AGS system*, I had to insulate the outside of the wall first using a DIY method described in detail in a recent post, as well as insulate the ground on which it would be resting. With the help of many volunteers, a formidable wall went up in about two hours time using foundation stones salvaged from a 19th century barn.  Then, while waiting for the Spring rains to subside, I shop-built the exterior wall sections that will house the windows and stored them on the house slab under cover.

Screened Porch Slab; Garage Slab; Retrofitted Concrete Wall
A lot of June and July was spent on the screened porch and the garage.  I formed up and
Footing, foundation and slab completed for the screened porch
poured the footings and foundation for the screened porch in preparation for the pouring of the porch slab by the concrete contractor.  As part of the umbrella for the AGS system*, I also worked on insulating the porch floor and insulating the garage floor so that the contractor could pour them as well.  I had miscalculated on the design of the east wall of the garage and ended up asking the contractor to add four feet of height to it in conjunction with his pouring of the porch and garage.  I recently spent a couple 
Pouring the garage floor; addition to the east wall of garage already poured
of weeks between rains insulating the new east wall of the garage.
  Also, I added one more layer of backfill to the north wall to bring it up to the top of the previously-installed damp-proofing membrane -- to a depth of about 8' -- (only to learn later through a comment submitted to the blog that I had installed it backwards).



*          *          *          *          *          *          *          *          *          *          *  

In a nutshell, it has taken me two years to be reach the carpentry phase of construction partly because the dirt and concrete phase has been so weather-dependent.  I would guess that it will take another two years to have the house ready for occupancy -- maybe 6 mos to get it under cover and 18 mos to finish it -- but the weather will be inconsequential by comparison since the work will be done on the slab floor and soon under cover. 

There will be more dirt work to do before winter of this year, principally, completing the umbrella for the AGS system* in front of the house, and more to do in back of the house next year but all of the concrete work and most of the dirt work are history.
_________________
* For information on the Annualized GeoSolar system, click on the "Featured Post" in the left column above which is the first of three posts on AGS.

Monday, July 25, 2016

Construction - DIY Concrete Wall Insulation

recent post delt in part with the construction of the concrete east wall of the future
garage pictured at the left with the French drain at its bottom.  It needed to be insulated exteriorly then backfilled to almost half of its height.  Here I am using that wall to demonstrate a DIY custom insulation method that I will be using subsequently for those parts of the north and west walls that lie above the horizontal insulation/watershed umbrella. (There is no need for insulation below the umbrella so as to maintain as much uninhibited earth contact as possible.) The method I am using was somewhat described in another post in conjunction with the first retaining wall west of the house. What follows is a more detailed account. Remember that a click on any photo enlarges it for better viewing.

Acknowledgement
The DIY design described here is a bastardization of the proprietary product Insofast.  Perusal of the Insofast website was encouraging -- the product would seem to be perfect for insulating our concrete walls inside and out. However, for our  requirements, their quote was at least $3,000 more than the following DIY method.  And Insofast maxes out at an insulation thickness of 2.5", which would have worked for the garage, but not very well for the house. Nevertheless, I am indebted to Isofast for stimulating improvisation.

Overview
Essentially, the insulation is expanded polystyrene (EPS) (styrofoam) supported by metal drywall track (ordinarily used as the bottom member of a metal stud wall, i.e., the part that is fastened to the floor).  Even though the track is galvanized, there would be a limit as to how much moisture it could endure before rusting so I am wrapping the entire assembly in plastic sheeting to isolate it from the concrete on one side and from the outside environment on the other side.  The secondary function of the track is to support the cement board cladding that serves as a base for the stucco finish.

From my drywall supply company, the track comes in two widths -- 2 1/2" and 3 1/2" -- and two gauges -- 20 and 24.  For the garage where maximizing the R-factor is not critical, I used 2 1/2".  For the house walls, I plan to step up to 3 1/2" track for a higher R-value.  As for thickness of the track, the thicker 20 ga is more suitable for supporting the heavy stucco wall.  It then takes two thicknesses of  foam board --
1 1/2" and 1" -- to fit the 2 1/2" track. The plastic sheeting is good quality 6 mil that I buy from a farm supply store in 24' widths -- the kind sold to farmers probably for covering hay. 

My original intention was to use one thickness of 1/2" cement board but, after finding that it was not rigid enough to support a thin layer of stucco, I used two thicknesses. Even two thicknesses would be too compressible and would have to be backed up by something more rigid for long term durability in high traffic areas.  In our case, most of the insulated concrete walls will be below grade after backfilling and most of those above grade are away from high traffic areas.  The lone exception is the east wall discussed here; it will be in a high traffic area but less than half of it will be exposed.

Therefore, I covered the top of the first layer of cement board with a pressure treated 1 x 6 and butted the second layer of cement board up against it.  Not only does the 2 x 6 make the top of the insulation more rigid but it also widens the wall by 1 1/2" which will work better with the stick-built truss wall above it.

Shop-Made Tracks
The drywall tracks that support the insulation and the cement board were shop-made
Drilling holes for the Tapcon screws 
ahead of time.  All but the first track at the south end of the wall and the last track at the north end have to be back-to-back.  Before screwing them together, one of them was
Pre-made tracks already cut to length for the north garage wall
perforated on one of its short sides with holes large enough to accomodate the 3/16" Tapcon screws that fasten them to the concrete wall.  The drill press and a long wood block cut from a 2 x 4 to fit inside a track and marked to guide hole placement made short work of holes drilled 8" apart, which was more frequent than necessary but it gave more options for screw placement during installation.  Next, the pre-drilled track was clamped  back-to-back with another track and the two of them screwed together with metal screws in pre-drilled starter holes.

Screwed-together double track showing holes for Tapcon screws in the bottom piece
Jumping ahead to the time when the tracks would be fitted to the wall, let me share what I found to be the best way to cut them to length.  Use straight-cutting metal shears to cut all four short sides at the cut mark.  Then, instead of trying to cut across the long dimension of the back-to-back tracks, simply to bend the tracks back and forth a few times to "worry" the metal into separating.

Pre-cut Foam Board
Purchasing ESP is cheapest in 4 x 8 sheets but, to fit the present situation, the sheets need to be split lengthwise into 24" pieces.  I have sawed them by two methods and prefer one over the other for the sake of accuracy. The less desirable method is to use a straight edge guide and a circular saw.  Accurate cuts are difficult for several reasons that I will leave up to the reader to find out for him/herself.  The other method is to get someone to help run the sheets through a stationary saw against a proper rip fence. For this, I have used both my table saw and my radial arm saw.  (The latter works for me because the saw table is quite long -- 16' -- which is atypical for arm saws.) Either saw does a splendid job of making a mess of the shop, so I recommend planning ahead and cutting as many sheets as possible in one session to minimize the number of times the mess has to be cleaned up.

The advantage of using a stationary saw is that the sawn edges are straight and each piece is a standard width.  The straighter they are the better they fit the tracks and the less air space exists between the foam and the track.  Air spaces are also minimized by having consistent and matching widths of the two pieces of foam that go together to fit the track.  I had some 1 1/2" foam pieces left over that were cut with the circular saw for the west wall behind the retaining wall.  When they were matched with the 1" that were cut with the radial arm saw, there were air spaces up to 1/2" in some cases -- which was acceptable for a garage wall but would not be for the house walls.  And a stationary saw is mandatory for accurate cutting of thin sheets like the 1" due to the foam's flexibility (even when they are doubled up to increase rigidity).

The pre-cut 1" and 1 1/2" foam panels are easier to cut to length and install between the tracks when they are glued together.  Accordingly, a spray adhesive specific for EPS did the trick.  Just be careful that the edges are flush when gluing. 

Installation of the Track and Insulation Panels
In order to protect the track from moisture, the plastic sheeting must be in place before the
Plastic sheeting covering the near side of the wall;
remainder thrown over the top of the wall temporarily;
 four tracks installed supporting four courses of insulation
first track is installed.  
The 24' width of the 6 mil plastic sheeting was a little more than the length of the wall so all I had to do was cut a piece from the roll that was a couple of feet longer than twice the height of the wall.  It was draped over the wall so that it reached the ground and turned outward a foot or so on the near side of the wall.  The balance of the sheet went over the top of the wall and hung down on the far side temporarily. The plastic was left long towards the south (left) end of the wall so that later it could be folded under the cement board in such a way as to protect the left side of the first track.
Tracks and insulation installed, ready for cladding


The south corner track, a single member rather than back-to-back, was cut to length and screwed to the wall through the plastic using a hammer drill, drill/driver and 
1 1/4"  x  3/8" Phillips head Tapcon screws. The first section of foam was cut to length and fitted into the single track, in this case, to the left.  The next (double) track was then slipped over the right side of the foam and pressed by hand or even tapped with a block of wood and a hammer so as to eliminate as much as possible any air spaces between the foam and the left and right tracks.  It was installed with the track having pre-drilled holes to the right. While holding the track firmly towards the left, the right track was screwed to place through the plastic sheeting.  The remainder of the sections were installed in a like manner.  At the north end, the plastic sheeting was folded back over the last track to protect it from the right side.

Installing the Cement Board
Sheet plastic folded back over the wall so as to protect
the tracks and insulation from the exterior environment;
first layer of cement board partially installed 
The cladding comprised the cementitious (cement) board and a top coat of stucco both of which will always absorb some moisture from the environment. So the plastic sheet was brought back over the wall to cover the top of the insulation, hang down in front of it and extend over the French drain at the bottom so as to separate completely the insulation and tracks from the cladding and direct any running moisture to the drain.

Unfortunately, the cement board comes in 3' x 5' panels which doesn't equate well with the tracks on 24" centers.  So they had to be cut to width as well as length which is best done with a nibbler rather than a circular saw in order to avoid the noxious and health-impairing dust.  My nibbler was originally purchased for $80 on Craigslist at a time when I thought I would be gladding the exterior of the house with fibercement board (which later morphed into preference for steel siding which will require a different nibbler). It wasn't until later that I found out that I was lucky to have the fibercement nibbler because it cuts cement board as well.

The installation of the board was time-consuming.  In order to hang it with the same
One-by-six in place; second layer of cement board
butted up against it and ready for parging with stucco
cement board screws that are used for fastening the board to the bathroom floors and shower wall studs, pilot holes had to be drilled in the metal track.  And in order to keep the twist drill sharp for the metal, holes had to be drilled through the cement board first.  This meant three tool changes -- a cordless drill with a 3/16" masonary bit, a cordless drill with a 1/8" twist drill and a drill/driver for the screws.  


The mismatch between the cement board sizes and the 24" OC of the tracks created multiple left-over pieces.  Since I knew that there would be two layers of cement board, I didn't hesitate to work the small pieces into the wall for the first layer even though they were not as rigid as large pieces.  The 3' x 4' second layer pieces covered up the multiple seams of the first layer and added rigidity.  

Adding the Stucco
Fortunately, parging the cement board with stucco was easy after my experience with fiber bonded cement for the dry-stacked block walls of the solar connector.  The material that I
Wall after stuccoing; French drain covered with a layer of
 clean rock; 
about half of the wall will be buried in
backfill starting with +/- 4' deep at the north corner and
ending with +/- 2' deep at the south corner 
used was Quickcrete Professional One Coat Fiberglass-Reinforced Stucco.  And, as with the fiber bonded cement, getting the consistency just right is critical for easy handling. If it is too dry, it falls off instead of sticking to the wall and, where it does stick, tends to be too thick.  If too wet, it falls off and, where it does stick, tends to be too thin.  With a little experience, the right consistency goes on easily a trowel-full at a time (painfully slow) and can be troweled to a rather smooth finish. The manufacturer recommends limiting the size of each mix to that which can be applied in one hour.  An 80 lb bag mix was about right for meeting the time requirements during the hot summer after I waited to start the project in the afternoon when the wall was in the shade.


It is mandatory to keep a hose or sprayer handy.  Whether the substrate is concrete, other stucco layers or, as is the case here, cement board,  it must be kept moist for the stucco to adhere properly.  And the stucco should be kept moist for a couple of days afterwards to control crazing due to shrinkage as it cures.

In the present situation, both layers of the plastic sheet were trimmed so as to overlay about half of the top of the French drain so that any moisture between the inner sheet and the wall or between the outer sheet and the cladding will be directed to the drain but without completely covering the drain with plastic.

Interior Surface of the Concrete Walls
The east wall of the garage used here as an example and all of the concrete house walls that are insulated on the exterior will be insulated on the interior in a similar way using plastic sheeting, metal track and ESP foam board.  The only difference will be drywall for cladding instead of parged cement board.   

Insulating both sides of the wall will give a nominal R-20 for the garage where 2 1/2" tracks were used and R-28 for the house walls where 3 1/2" tracks were used.  An R-20 for the garage is probably overkill but an R-28 for the house is marginal compared to the 
R-50-ish stick-built walls and ceilings.  Fortunately, I can live with it since the amount of concrete that will be exposed above the insulation-watershed umbrella will be minimal. 

Backfilling Against the Wall
Provisional backfill to ward off the runoff from behind the wall;
the carpentry  work can now resume  in earnest
The reason for interrupting the carpentry phase and concentrating on the garage wall was to insulate and clad it so it could be partially backfilled to force the runoff from the the backfill behind the house away from the east garage wall and to cover the French drain.  Accordingly, I dropped a few track loader buckets of dirt against the wall to suffice until the entire slope could be properly contoured eventually.