Step 12 – Wall Sheathing

With the roof underlay on, the structure is now safe from direct rain, but there is a ton of wind here in Point Roberts thanks to the proximity to the ocean, so wind blown rain is still a threat. Installing the wall sheathing will solve that problem, at least for the short term.

Many builders apply the wall sheathing to the studs before they even stand the wall up. This would have required me to rent some heavy equipment, so I decided against it. Another good thing about installing the sheathing now as opposed to earlier in the build, is that I was able to wait until I was sure that the interior of the structure was nice and dry. If I had attached it earlier before the roof was on, rain would have soaked everything from above and then the sheathing would have blocked all the wind from drying everything out.

The wall sheathing serves several very important functions besides acting as a blocker to wind blown rain. Most importantly, it provides the necessary wall bracing to adhere to building codes.  Second, it functions as the integral part of the outer air barrier, which is crucial to achieving net-zero.  Last, it will provide nailing support for the exterior rigid insulation.

Sheathing the walls solo, like the floor and roof sheathing, required a few creative bits of ingenuity.  The 4 foot high and 8 foot long sheets weigh a little over 45 pounds, and the top row of sheathing must be installed 20 feet up in the air.  Just carrying one of these sheets is cumbersome, let alone figuring out how to hold it in place and nail it with only 2 hands.  On top of that, I had to figure out how to apply a bead of caulk around the edges of the sheets and at window openings, and keep in mind that some of this would need to be done on a ladder.  The task at hand was quite daunting, but after thinking it over for a bit I was able to come up with some techniques that worked surprisingly well!

Before the sheets could be installed I had to attach some blocking halfway up each wall, in between all the studs.  This is required for wall bracing to ensure the sheathing is fully attached to the structure.  I had several extra 2×6 studs from a minor mistake I had made when ordering the framing lumber, so I ripped them in half and then cut them to fit between the studs.  Each block was end nailed to the stud on one side, and then toe-nailed on the other side.

Marking out windows and studs before installing the sheet made nailing a lot easier

Attaching the first row of sheathing was obviously the easiest.  I snapped a chalk line halfway up the bottom plate and then sank a few 16d nails just below it so that if I rested the board on the nails, the bottom of the board would line up with the chalk line.  Next, I grabbed a sheet of plywood from my stack and drew a line every 2 feet.  This would make knowing where the studs were for nailing much easier.  Next, I grabbed my caulking gun and used Dynaflex 230 to lay a bead of caulk along the top of the bottom plate, the bottom of the blocking, and the two studs where the ends of the sheet would be.  I also caulked all the way around any window openings that would be under the sheet I was installing.  After that it was a simple matter of lifting the sheet onto the nails at an angle so the top of the sheet wouldn’t smear the caulk, then positioning it precisely, and last pushing it into the wall and nailing it down.  Each sheet was nailed every 6″ along the edges and every 12″ on the lines I had drawn.

Plenty of caulk along the edges of each board and around windows will ensure an airtight barrier

Installing the next row wasn’t a whole lot more difficult.  I sank 16d nails on each stud just over the top of the previous row of sheathing.  This will leave a small gap between the rows which will allow for expansion due to heat and moisture.  I marked lines every 2 feet to line up with the studs and caulked just as I had with the sheets in the first row.  Then I hoisted the sheet up on top of my homemade scaffolding and then used a ladder to get myself up on the scaffolding as well.  From here I could install the sheet just like the first row by angling it onto the nails, positioning, and then pushing it to the wall and nailing it down.

The third row got a little more tricky.  I installed more blocking, snapped a line marking where the top row of sheathing should go, marked lines every 2 feet on the sheet, and caulked.  Then, from the second floor inside the house, I clamped my winch to the top half of the stud that would lie in the middle of the sheet, and used a c-clamp to attach the belt to the sheet of plywood.  Then I cranked up the winch until the sheet was at the right height, positioned it from inside the house on the second floor, and reached around with my nail gun to tack it down.  Then I removed the c-clamp, went downstairs, and climbed a ladder to finish nailing down the panel.

On the gable ends, I was able to install the final row just like the third row by simply moving the winch up to the gable end truss and attaching it there.  On the other two sides I had nothing to clamp the winch too!  After trying in vain for quite some time figuring out how to do it on my own, I realized this might be one of the times I needed to call a friend over.  I drilled holes in a couple of scrap blocks and nailed them to the frieze blocks, and ran one of my nail stakes left over from the foundation through the holes.  Then I ran a rope around the nail stake so both ends dangled down at the bottom of the house.  I attached one end of the rope to a c-clamp around the plywood, and left the other end dangling.

Here you can see the bar we used to help us lift the last of the sheets into place

When my friend arrived, I caulked the area where the sheet would go and then he stood on the second story and hoisted up on the rope while I simultaneously pulled in the slack at the bottom.  Once the sheet had reached the top, I nailed a second stake into the ground and tied off the rope so we could both let go and the board would stay in place.  At that point I climbed the ladder with my nailgun and gave him instructions on which way to nudge it so it was perfectly positioned and then nailed it down.

 

It may look pretty boring now, but the interior is protected from the elements!  The exterior of the plywood sheathing will definitely still get wet, but the water won’t leak through and the inside will stay nice and dry.  I will wait until it gets a little warmer in a couple months so I can be sure that the outside of the house is completely dried out, then I will install the exterior foam, water barrier, furring strips, windows, etc.  In the meantime, it is nice and dry inside and I will be starting on the plumbing!

A huge thank you to my friend PJ for his help, both with coming up with the idea on attaching the bar to the house and for his strength helping to hoist the sheets!

 

Step 11e – Drip Edge and Underlay

Today I weathered in the roof by installing the drip edge and underlay.  Together with my fiancée, Elena, who is in charge of making the house look great, we decided on navy blue/grey aluminum shingles for the roofing material.  Aluminum is supposed to hold up well against the salty ocean air of Point Roberts and the system I ordered from the Aluminum Shingle Co. came with a lifetime warranty.  This becomes extra important for a solar net zero home like the one I’m building because if you have to replace the roof then you have to remove the entire solar system first.  The aluminum shingles are built to interlock together, which not only makes installing them a little easier, but also ensures an extremely watertight barrier.

The first step in the install was to attach the drip edge to the eaves of the roof.  For the aluminum shingle system, the drip edge came with the package because the shingles will actually lock into it (even the nails to install it were included!)  For a more typical shingle roof, the drip edge can be purchased separately.  The job of the drip edge is to ensure that water doesn’t drip down the fascia as it travels to the gutter.  The face of the drip edge extends out over the fascia so the water coming off the roof drops directly into the gutter without touching the fascia.  After watching the installation video a few times, I carried the drip edge up to the roof and set about installing it.  Some small cuts had to be made with some tin snips where the different pieces locked together but overall the process was extremely simple.

Getting the roll of underlay up to the roof was probably the most difficult part.  It weighs close to 100 pounds and wasn’t quite wide enough to ride up the rails that I had used to haul up the roof sheathing.  I decided the best way to do it was to unroll a little more than the amount I needed to complete a row, cut it off, and then roll it back up.  Then it was light enough where I could carry it up the ladder safely.  Starting at one end, I nailed it down so it almost covered the nailing flange of the drip edge and then unrolled it all the way to the other side.  After tacking it at the end and cutting the roll flush with the gable end, I nailed it down with cap style roofing nails every 8 inches or so.

Step 11a – Frieze Blocks and Baffles

Working on the roof definitely has its perks when it comes to sunset!  Doesn’t show up as well in the picture but I had a beautiful view of a snow covered Mt. Baker there.  So when I ordered the roof trusses, I had specified that I wanted a 15″ energy heel.  This feature ensures that the attic insulation will maintain it’s full strength all the way to the edge of the wall.  I will be using blown-in cellulose insulation in the attic and to achieve my desired strength of R-60 I will need about 16.5″ of insulation (blown cellulose has an r-value of about 3.7 per inch)  A standard truss would slope all the way down to the top plate, leaving only the width of the truss chord between the ceiling and the roof.  For a net-zero home this is unacceptable.  So before we can apply the roof sheathing, the sides of the walls need to be built up to the same level as the roof, otherwise the cellulose would just fall out after we blew it in.

 

The pieces used to build up the wall are called frieze blocks.  If you look closely, you can see how I had to add in a layer of plywood to ensure that the blocks were tall enough.  In addition, I beveled the top edge of each block so that it would match the slope of the trusses.  Any place in the house where insulation exists, it becomes very important to have an airtight seal all around it.  The beveled edge will make it much easier to air seal the frieze block to the trusses on the sides, and to the roof sheathing on top.

 

You might notice that every third frieze block is a few inches shorter than the others.  The spaces there will be used for baffles.

A baffle is used to ventilate the attic.  Even with a perfectly installed roof and airtight seals all around the insulation, moisture has a knack of finding its way into pretty much anyplace you don’t want it to be.  The most effective way to remove this unwanted moisture that could potentially lead to rot and mold is to use moving air.  The air will enter the attic through the baffle and warm slightly, causing it to rise and eventually exit through the ridge vent at the peak of the roof.  As the air completes this journey, it will pick up any moisture that exists in the attic.  As you can see below, the baffle is more than just an opening through the wall of frieze blocks.  It is actually more like an air tunnel that runs over the top of the insulation.  Again, recall that it is extremely important to ensure no moving air comes into contact with the insulation. 

If you can imagine the roof sheathing going on over the top of this baffle, it will create a 2 inch wide air tunnel through the attic between the two layers of wood.  Below you can get a good look at the frieze block from the bottom.  Several months from now, practically this entire area you see will be filled with energy saving insulation.  You can also see where I added hurricane ties to lock the trusses to the top plates of the walls.

 

 

 

 

 

 

 

Step 11 – Install the Roof

The first part of building the roof is to “roll trusses”.  Although some old fashioned builders prefer to frame their roofs one piece of lumber at a time, when building solo it can be dangerous to handle large roof framing members when you are two stories up in the air.  Most modern builders order the roof trusses premade and then have them placed on their sides on top of the house with a crane.  Then all you have to do is to drag each truss to it’s proper location and roll it upright to a vertical position.

Before they arrived I made sure to plumb and line the second story walls. This was relatively easy because with the floor already in, I knew the first story was locked in very tightly. This meant I could use it to brace the second, which I did with the plumb bob and 20’ 2x4s just like I did on the first.  On a side note, if anyone ever tells you that it’s impossible to carry 20′ 2x4s in a Ford F-150 without a $300 rack you can show them this as proof they are wrong.

The trusses arrived on a long flatbed, and the driver used a crane to hoist them 20’ up to the top of the second story wall.  They came in two stacks so I had him lay one down in the middle of the house and the other standing up at the other end. I used some long vertical 2x4s to support the vertical set so they wouldn’t fall over the side of the house.   I was fortunate to have my friends Michael and PJ helping me as the 24’ long, 5’ high trusses are pretty heavy for a one man operation.

Here you can see the three long vertical 2x4s and a small clamp at the bottom that is holding the trusses tightly against them

We started with the stack that was lying down.  We grabbed the gable end truss and slid it down to the other end of the house where we slowly, carefully stood it up against vertical 2x4s just like the ones at the other end.  We nailed it to the top plate flush with the end, and then nailed a small 2×4 block to prevent the truss from falling back down. I had precut these pieces, which are called bird blocks, to 22 7/16” so they would fit snugly in the spaces between the trusses. We slid the next truss down and lined it up against the bird blocks, then used a 2×4 as a pole to push the truss up into its vertical position.  At that point we would end nail it into the bird blocks, and toenail it into the top plate.  Below you can see all 3 pieces together, with the trusses resting on the top plate, and the bird block fitting in between them.

We continued to repeat this process until we had rolled all the trusses in the first stack.  At that time, we ran a few 1×4 boards along the inside of the top chords to ensure they were spaced properly.  They also help to add lateral strength to the trusses to prevent them from rolling back over on their sides.  You can see them as the two darker lines near the center of the photo.

The second half of the trusses were installed in much the same manner, but was a good deal easier since the crane had already placed them standing up.  For these trusses, I installed the 1x4s first, and then used them as rails to ensure that the trusses would remain upright as we slid them into position one at a time.  If you can imagine how the rings on a shower curtain slide across the curtain rod, it might help you visualize the trusses sliding along the 1×4 rails.

If I haven’t made it clear before, building a house can be quite a surreal experience.  Here I am standing on top of a second story wall taking the above picture and marveling at what a phenomenal day it is while most of the rest of the world is hard at work, slaving away at jobs they don’t like to slowly chip away at 30 year mortgages.  If they only knew they could build a beautiful net zero home in such a serene suburb of a major city for less than 200k.  Oh, and not just any city – Vancouver was the only North American city to crack a European-dominated top 10 quality of living ranking of global cities.  (Mercer – 2017)

It looks a little messy with all the long 2x4s sticking up at the top and diagonally bracing the walls but this is the complete skeleton of the house!

Step 8b – Frame the Interior Walls

In my last post, I discussed how using advanced framing would help me lower my heating bill by creating more space for insulation.  However, insulating a house is just one of the ways to reduce the amount of energy needed to heat (or cool) a house.  No matter how much insulation I put in the house, if I don’t control the air that is allowed to flow through the walls  it will be impossible to control the temperature.

Air is able to transfer heat using convection.  This is great when you are using a furnace or a heat pump to blow nice hot air into the house during the winter, but in many houses, that air is allowed to escape back outside through tiny cracks and crevices all throughout the house.  According to the US Dept of Energy, up to 30% of heating and cooling cost is due to lack of air sealing.  One of the places where air can escape is in the tiny gap between the sill plates of the walls and the concrete foundation.  While I did place a sheet of sill gasket in that area, that was only to prevent water from wicking up the concrete and into the walls.  The sill gasket is air permeable, meaning air can pass through it.  I needed to add an additional layer that was air impermeable to fill the gap, and some all-weather caulk fit the bill nicely.

Countless houses leave this crucial step for later, or skip it altogether.  The best time to do it is now, though, because after I frame the interior walls it will be nearly impossible to caulk the spaces where they connect to the exteriors.

Image result for continuous drywall intersection

Another technique I will be utilizing to control air movement is using “continuous drywall”.  This means that the drywall will slide in behind the wall framing for the interior walls, resulting in fewer joints in the drywall and thus fewer opportunities for air infiltration.  Each of these small details contributes just a little more energy savings and helps to get the house to achieving net-zero.  Above you can see a pic of an intersecting wall with continuous drywall, which is the method I will be using, and below is a traditional method that the majority of builders use.

 

 

 

 

 

 

The drywall won’t be installed until later in the build, at least until the roof and siding are installed.  Drywall doesn’t perform very well when it gets wet.  This means I will need to leave a gap in between the exterior walls and any interior walls that run into it.  I cut small scrap pieces so they were 3/4″ thick and used them as spacers to ensure the gap was sufficient.  Even though the drywall is only 1/2″ thick the extra 1/4″ will allow me to slide it in the gap without damaging it.  I used the spacers at both the bottom of the wall and at the top as you can see below.

You can also see the line of caulking that follows the entire perimeter of the house

Splice plates are used to hold the top of the wall in place

I used standard framing instead of advanced framing for the interior walls since they don’t require any extra room for insulation.  This meant spacing the studs at 16″ on center instead of 24″ like I did with the exterior walls, and capping the studs with a double top plate instead of a single.  Additionally, I used 2×4’s to frame most of the interior walls instead of the 2×6’s I used on the exterior.  I did use 2×6’s on several of the interior walls that contained large plumbing pipes.  This will give me a little more room to play with as some of the pipes are over 3″ in diameter and the 2×4’s are only 3.5″ wide.  Beyond that, framing the interior walls is just the same as the exterior.  Mark the stud locations on the top and bottom plates and then nail them in.  A few details were needed for bedroom and bathroom doors as well as intersecting walls but overall it is a pretty simple process.  The second top plate is added on after the walls are up and is staggered in a way that ties all the walls together as you can see below.

 

Step 8a – Utilize Advanced Framing Techniques

To an experienced framer, the work I have completed over the last couple of days would seem wrong.  It is quite possible they would never have seen a house framed the way that I am framing mine.  A few might even claim that I am violating building codes in not following “standard practice”.  The fact is, I am utilizing a method of framing created in the 1970s in a collaboration between the U.S. Deparment of Housing and Urban Development and the National Association of Home Builders Research Foundation.  Their goal was to reduce the amount of wood used in construction, not only to save the lumber, but more importantly, to create more space for insulation and save on energy usage.  All of these small changes work to ensure the house will be net-zero!

Image result for photo of advanced framing vs traditional

As you can see above, in traditional framing you have a single sill plate at the bottom of the wall connected to a series of studs spaced 14 1/2″ apart from each other (16″ on center) which are then connected to two top plates sandwiched together.  Additional shorter studs called “jack studs” are used to support headers above window and door openings.  Even more studs are used to anchor interior walls to the exterior.  All of the wood used are 2x4s, leaving 3 1/2″ of space between the studs for insulation.

In advanced framing, on the other hand, only a single top plate is used, studs are spaced 22 1/2″ apart (24″ O.C.), and metal “header hangers” are used instead of the jack studs.  On “gable end” walls, no headers are needed at all! (see below) “Ladder framing” is used to anchor interior walls and 2×6 lumber is used, leaving 5 1/2″ of space for insulation (obviously that’s the part of the wall that looks like a ladder in the pic)

The advanced framing system is cheaper because it uses 5% to 10% less lumber, and it is faster because it uses 30% fewer boards (although they are a bit bigger and heavier). More importantly, every single year more money is saved on energy costs because over 60% more insulation can be filled in.

This is a gable end wall, meaning it will extend all the way to the peak of the roof without slanting. Because of this, you can see I don’t have to use headers above the windows. (And yes, that is just a very light dusting of snow)

Okay, so what’s the catch?  If advanced framing was added to the building code over 40 years ago, is cheaper and faster, and reduces the energy bill every single month, then why isn’t it standard operating procedure for builders?  How could I possibly be telling you that most builders don’t even know about it?  While I could devote several pages answering that very question, I’ll do my best to sum it up quickly.  Building a house is difficult.  There are very few people who have the knowledge to do it all themselves and I may very well fall flat on my face in trying.  For me, that challenge is exciting, even if it is frustrating at times.  Because of this fact, the vast majority of houses are built by a massive team of “contractors” that under normal circumstances communicate very little with each other, if at all.  These tradesman are managed by a “general contractor” who uses building plans that were probably drawn up by an architect and edited by an engineer.  Although I was able to sum up the advanced framing techniques in a couple sentences, the small changes affect every single one of these workers.

Image result for photo of advanced framing vs traditional

The architect and the engineer must design the house from the very beginning so the floor joists and studs stack up within an inch of each stud (see pic above)  This puts a sort of limiting factor on the architect in regards to wall lengths and window placements that many are resistant to.  Next, the general contractor must be open to training the contractors under him because many of them will be unaccustomed to the framing.  The framing crew will be working with a different length of wood due to the single top plate, and have to frame completely differently than they are used to.  The electrician has fewer studs to attach electrical boxes to.  The drywall crew has fewer studs to nail the drywall to and may have to hang it differently.  The small changes ripple right on down the line and affect every single person that works on the house.  As contractors are paid by the job and not by the hour, they aren’t too keen on taking time to learn this new technique.  The fewer that learn it, the fewer that are available to teach it, and the cycle continues…

As I’m building solo, I have none of these issues.  I designed the house myself from the very beginning with advanced framing in mind.  Thanks to my mentor, who introduced me to advanced framing, I’ve never built any other way.  I saved money on lumber and nails.  I saved time with fewer studs to nail together.  I saved trees because of using less lumber (I’ll be using dense packed cellulose in the spaces where the studs would have been which is made of mostly recycled newspaper and denim).  I will save money on my energy bill each month (or be able to use a smaller solar array).  I even save time building because with the larger spacing between studs I can jump in an out of the house anywhere instead of using a doorway.  If you really want to save sustainably, advanced framing is the way to go.

 

Step 6c – Inner Forms, Plumbing and Bracing

I could save a lot of time and some money by pouring the concrete for the footings and slab at the same time, in which case I would be done with the formwork now.  For several reasons, I decided to pour them separately, so I needed to add an additional set of forms before I pour.  The double pour will allow for more control, hopefully resulting in a smoother, more level slab.  It also allows me to insulate the inside of the footing wall, instead of the outside.  You can always add insulation to the outside of the wall anytime you want if needed to reach the net-zero goal, but you can never add it to the inside once the concrete has been poured.

I set up the second set of forms exactly 8″ apart from the first set to create the 8″ stem wall required by the local building code.  The set up method was no different than that of the first set of forms: stakes in the ground, forms nailed to the stakes, scrap wood screwed to the forms to hold them tight to each other with no gap in between.  I attached the two forms together with the precise 8″ gap using some scrap wood.  I placed these scraps at the exact locations where my anchor bolts will go.  This way, I can use the scrap wood to hold the bolt while the concrete cures around it.  The conventional way is just to throw the bolts in wherever you “think” you might need them as the concrete is curing.  This often results in bolts ending up where studs or plumbing is supposed to go and needing to be cut and replaced, so the method I’m using is much more efficient.

 

Once the second set of forms were attached and level with the first set, I began straightening them out using the bracing shown here.  The boards may not look pretty, but they are free and I can’t see spending money on temporary bracing.  When it comes time to pour concrete, we will be banging the forms with hammers trying to work the air pockets out of the concrete so I need to ensure the forms won’t move around at all.

With the forms perfectly marking out the edges of the house, I now had a reference to place the plumbing.  Here you see the plumbing for the toilet which has to exit the concrete slab at the precise location where the toilet will go.  Notice that there is not a trap in the pipe because toilets have traps built into them.  When I connect the plumbing for the tub you will see that there is a u-shaped trap under the concrete that will hold a pocket of water and ensure that the gases from the septic tank don’t enter the house.  When bracing the main pipe here, I will need to maintain a downward slope of 1/4″ for every foot of pipe all the way through the line to the septic tank.  I used the builders level again to make sure that I was starting at the right spot.  Using the spec sheet that came with the septic tank, I know that he inlet is exactly 17″ below the top of the inspection ports that are visible from above.

The edge of the forms where the main sewer pipe will exit the concrete is a little less than 10′ from the inlet port, so the pipes must exit that spot 2.5″ above that height (10′ at 1/4″ per ft= 2.5″).  From there it gets much easier as I just had to slope the pipe at 1/4″ per foot until the end of the line.

The last step before the pour will be my electrical and utility sweeps, so be looking out for that in the next post!