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 10 – Frame the Second Floor

You can see how I’ve been trying to keep the OSB flooring dry with a tarp but with the walls going up it is difficult.  Luckily, I spent some extra money on Weyerhauser EdgeGold OSB subfloor and according to their reps they are perfectly fine to get wet for a few weeks as long as they are given time to dry out.

Framing the second floor is not a whole lot different from framing the first.  Whereas on the first floor, the sill plate was pressure treated lumber, this isn’t necessary on the second.  Also, the bottom plate was bolted to the concrete foundation on the first floor, but on the second we simply nail it to the rim joists as you can see below.

Before raising the exterior walls, I toe-nailed the inside edge of the bottom plate to the floor boards.  These nails help enure the wall stays in position and doesn’t fall off the house before it gets nailed into place.

After going up and down the ladder many times cutting pieces for the walls I decided it was time to build something permanent.  The finished house will have a large spiral staircase but it would get messed up pretty quickly during building (as well as annoying) so instead I just threw together a makeshift ladder from some scrap wood.

Whereas the first floor walls were pretty simple, things got slightly more complicated on the second floor with the master bathroom as it has walled off areas for the shower, toilet, and two walk-in closets.  Several of these walls are angled, and one of the master bedroom walls is actually curved! 

Creating an angled wall is pretty simple.  You can see I have two walls meeting at a 45 degree angle on both the left and right side of the picture.  All you do is miter both top plates and bottom plates at 22.5 degrees so that when they fit together they create a 45 degree angle.  You can see how the studs meet on the inside wall and the small gap on the outer wall will be covered with a metal corner bead under the drywall.

At the center of the pic above I actually have three walls coming together in the shape of a ‘Y’.  For these I mitered the two arm walls with 45 degrees and joined them to a straight wall.  When it came time to add the top plate I had to do cut a special piece to fit with a jigsaw.

To build the circular wall, I had some 3/4 inch plywood ready.  I created a makeshift compass to get the right radius for the wall and transfer it to the plywood.  Then I drew out a second radius exactly 3.5 inches smaller than the first for the inside of the wall plate.  Sandwiching two of these pieces together, I ended up with an equivalent to a ‘curved’ 2×4.

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The one thing about a curved wall is that it uses a lot of studs!  The far side of the wall will curve right around the spiral staircase when it is installed. (I haven’t cut the opening completely yet for safety)

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Step 8c – Plumb and Line

With all of the 1st floor walls complete, it was neat to be able to navigate the rooms and get an idea of the feel of the dimensions of the house.   Before moving on to the 2nd floor I needed to take some time to ensure that all of my framing so far is straight, level, square, plumb, and true.  (For those who don’t know what the last two are, plumb means perpendicular to level and true means both level and plumb at the same time)  Once the subfloor is nailed to the floor joists it will tie everything together so this was my last chance to make sure it was just right.

I started by double checking the lengths of the top and bottom plates, and the lengths of the corner studs.  Next, I used a plumb bob to ensure each of the corners was plumb.  I used long 2×4’s nailed diagonally and nail stakes in the ground to push or pull the end of each wall as needed to plumb the ends of the wall.  I knew the foundation was level, so since the wall lengths were equal and plumb, I knew the walls were square and true as well.  I repeated the process for each wall, and then checked each wall for straightness.  Now I knew the corners were right, but in the middle of the wall there might be some waving.  I nailed a 2×4 block to the top corner on each end of the wall and stretched a string tightly between them.  Using a third 2×4 block, I checked all along the wall to ensure this block fit snugly between the wall and the string.  Where necessary I used additional bracing to make the wall straight.

With the exterior walls (hopefully) perfect, it was time for the interior walls.  I used a powder actuated hammer tool to nail the bottom plates of the interior walls into place.  This uses a .22 caliber explosive to drive the nail into the hard concrete.  You insert the nail into one end, put the .22 caliber load in the middle, and then strike the other end with a hammer.  The blow ignites the load, driving the nail in.  I double checked all of the measurements for the walls to ensure they were straight and then used the powder actuated hammer tool to attach them to the concrete.

Once again, I used the plumb bob to square up the walls and attached them to the exterior walls with a splice plate.  I used additional bracing on the one long wall, but the others were so short that they should stay straight.

With this crucial step of straightening done, I was now confident enough to get going on the joists.

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.

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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 8 – Frame the First Floor

After spending the weekend spraying the new slab down every hour or so, it was finally time to get the walls up!  This process of “wet curing” concrete can add up to 50 percent more strength when done for 3-7 days because it prevents the water inside the concrete from evaporating.  While many contractors immediately begin framing the house the day after the concrete is poured with no problems, I played it safe and waited until the 3rd day to get going.

The first step was to “snap lines” (see pic above) where the walls would go.  This will help me to ensure the bottoms of the walls stay straight and square to each other.  I took several measurements of the footings, including the diagonal measurements from corner to corner, to decide where to start.  The footings came out really good, but not perfect (this is my first solo build, after all!)  There will be a few small areas of concrete that stick out a bit or don’t come out far enough.  This is no problem at all structurally and visually it will be covered up by the siding, but in taking these measurements I was able to position the walls to minimize it as much as possible.

Here you can see where the concrete sticks out a half inch

The exterior walls will be framed on 2×6’s, so the first lines I snapped mark where the inside edge of the bottom plates will go, 5.5 inches in from my starting corner (for those not in the know, a 2×6 is actually only 5.5 inches wide on average)  Snapping lines is done using a chalk reel, which is basically a spool of string inside of a metal casing.  The casing has a sliding door so that you can fill it with chalk, that way when you pull out the string it gets covered in it.  I would put the end of the string on my mark on one end of the footing and weight it down with my sledge hammer, then allow the chalked string to unroll as I walked to the other side.  By pulling the string taut against the concrete and then lifting it just an inch, the line snapped back down leaving a neat line of chalk behind.

Once I had marked all the exterior walls, I grabbed the first sill plate from my pile of lumber and cut it down to 20′ (most lumber yards give you an extra 1/2 inch or so).  I lined it up on my line and marked out the anchor bolt locations, and then drilled them out.  (Remember that the bolts were embedded in the concrete footings so just the top part is sticking out)  Then I placed it over the bolts and made sure it lined up just right.  I repeated the procedure all the way around each wall until I had all 4 done.  With the placement of the exterior walls now set, I was able to measure out the locations of the interior walls and snap those lines as well.  It will be much easier to mark them now and serve as a sort of map to where my interior walls will be going.

I had to call a friend over to help me carry the 32′ long LVL top plate from the lumber pile over to the slab, and we set it on edge next to the bottom plate, which I had also turned on edge.  I used some clamps to hold them together perfectly lined up, and then used a tape measure to mark out the stud locations every 2 feet.  I had ordered the studs precut so that saved me a lot of time.  I just had to carry them over from the lumber pile and then inspect them and “crown” them.  Lumber being a product of nature is never perfect.  Sometimes they have significant bends or waves in them and I will save those for later.  The straighter ones I will use now, but even the straighter ones have a bit of a curve or “crown” in them.  I lined the crowns up all going the same direction which will make it easier to straighten them out later in the build.

 

 

 

Once all the studs were laid out on my marks it was just a matter of nailing them together.  Building codes offer several different ways to satisfy nailing requirements, and the one I chose will be 3 16D nails to connect each stud to the top and bottom plates.  I took my time and carefully aligned each stud to ensure that it didn’t stick out on either side of the top plate.  It is situations like these where even with my lack of experience I can guarantee I put together a better wall than 90% of the framing crews since they are focused on speed over quality.

For the window openings, a larger piece of lumber must be used to carry the load from the opening that is missing a stud to the studs on either side of it.  Again, building codes dictate several ways to satisfy these header requirements, and for mine I chose a single 2×10.  I will also be utilizing some metal hangers to carry the weight of the header instead of shorter studs called jack studs, although you can see that I did use jack studs for the entry door in the pic below.

The jack studs are the ones that are shorter than the regular studs on either side of the door opening

Once all the lumber was nailed together, I unrolled some “sill gasket” and placed it over the footing where the wall will be hoisted.  I also nailed some long 2×4’s to the top of the wall.  As we raise the wall, these boards will swing out and brace it.  The wall was very heavy but with a few friends we were able to get it airborne with ease.  Once it was vertical, I staked down the bracing boards and then screwed the nuts down over large square washers on the anchor bolts.

If you look closely you can see the white sill gasket underneath the bottom plate

Within a couple days I was able to finish the remaining 3 walls and raise them into place as well.  It’s so much fun to see my vision becoming reality!

The long 2x4s in front forming an ‘x’ are the bracing pieces I was talking about

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!