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 9b – Install the Subfloor

Solving small problems is a huge part of building.  I’ve always enjoyed crossword puzzles and the like, so I shouldn’t be at all surprised that I am enjoying building the house so much.  Today’s problem was how to lift 24 sheets of OSB panels 11 feet up in the air.  (2 feet of foundation + 8 feet of wall + 1 foot of joists = 11)  You see, each panel is 4 feet wide and 8 feet long, and weighs 59 pounds, so not only are they heavy, but it is difficult just to get your arms around one.  My solution was to build a small section of scaffolding about 6 feet long and 5 feet high.  Then I would carry the OSB over to the scaffolding while holding it just like this guy is.

Turning it so the shorter side is down, I then lifted it up onto the scaffolding

Then I would climb up to the top, grab the end of it and pull it the rest of the way up.  This was easy once I had a couple of them already up there to stand on but for the first ones I had to just stand on a couple of 2×6 boards that I had laid out perpendicular across the joists.  Have I mentioned that building a house is a great way to face your fear of heights?  I lifted every single one of the 24 boards up to the top of the wall in this same manner.  The first row you attach is the most important one to be straight because all the other rows will interlock with it.  I used my chalk reel to snap a line 4 feet in from the edge to ensure that I got it just right.  Next, I applied a liberal bead of elastomeric construction adhesive to the top of the joists.

PL400 is highly recommended for subfloor gluing

I set the board down over the joists so it lined up with the one corner of the house and ensured that the other end was halfway onto a joist.  This is the reason why I lined the joists up 24″ on center.  The 8′ long panel spans 4 joists and on the outer joists it leaves enough space to share the joist with another panel.  Once the panel is perfectly lined up the code calls for it to be nailed with 8d common nails every 6″ on the edges and every 12″ in the middle areas where a joist runs under it.  The boards are marked out so you can easily find the spots where these nails should go if the joists were lined up correctly.  If you look closely you can see them…

You can also see how I left a small gap in between each board to allow for expansion due to heat and/or moisture.  Four of these 8′ long panels were enough to run down the length of the house.  For the next row, I cut a panel in half.  Staggering the seams in this way adds strength to the floor.  With the first two rows complete you can see how the staggering seams look.  Notice how I positioned the other boards so I could walk around as I worked.

When I got to the row above the blocking I used a sander to make sure that none of the blocks stuck up above the joists.  I also measured out where pipes would go through so I could easily find them later.  One of the pipe fittings stuck up above the joists so I had to cut a hole for it in the OSB.

There’s the pipe I cut out a hole for on the right side and if you look closely you can see where I marked out where the other pipe will penetrate the flooring as it heads up to the roof vent

Luckily I thought ahead a little bit and before I got to the last panel I cut out a hole for the stairway opening.  Otherwise I wouldn’t have been able to get back down!  The opening will eventually be much larger but for safety reasons I left it just big enough to allow for comfortable access.  I marked a warning on the areas that will eventually be cut out because there aren’t any joists underneath.  The OSB floorboards are strong but without a joist underneath they could easily break.

The last step was to run a circular saw all the way around the perimeter to remove any protrusions.  Because of the small gap between each board there was about a 1/4 inch left around the edges.  That and the stairway opening was the only waste I had.  This is very rare in today’s average construction job as the house plans usually call for a bunch of details and angles in the floor.  Contractors cut panels in all sorts of ways as needed and then discard what they don’t use, which can be a substantial amount.  This is one of the benefits of designing a house yourself.  I specifically designed the house with dimensions divisible by 4 feet for this very reason.

Step 9a – Install Blocking and Plumbing

Before the subfloor can be nailed onto the joists, small sections of 2×12 called “blocking” must be installed.  Together with the rim joists they ensure that the floor joists won’t roll onto their flat sides where they can easily bend.  The blocking is placed along the top of the interior bearing wall at the exact place where the two floor joist spans meet and nailed perpendicularly between them.   I kept all the plumbing of the house on interior walls so I wouldn’t take any precious space away from my insulation inside the exterior walls.  My interior bearing wall being the major wall on the first floor, this meant that it had a significant amount of plumbing running through it.  The plumbing runs through the middle of the wall, and all of the DWV pipes must be vented vertically through the roof.  These pipes want to go through the middle of the interior bearing wall and exit right into the middle of my blocking!  My solution was to simply install a double set of blocking with the pipes in the middle.

Here you see the normal blocking at the outer edges of the pic and the modified blocking in the middle. The 2×6 boards at the bottom of the pic are for me to walk on until the floorboards are installed! Note how the joists from each exterior wall meet in the middle at this point.

In addition, I had planned for some of these pipes to run horizontally in the space between the floor joists.  For example, the washing machine is on the second floor, but the space I want to put it in doesn’t have a wall below it on the first floor.  If I didn’t run the pipe horizontally I would have a pipe for the dirty clothes water running through the center of the guest bedroom!  So this horizontal run would need to make a turn through the blocking so it would run in the space between the floor joists.

The pipe on the left makes a 90 degree turn to run between the floor joists while the one on the left goes straight through the blocking and will continue through the 2nd floor walls and out through the roof

 

 

All of my planning really paid off because some of the runs of ABS pipe were required to have cleanouts.  If I hadn’t installed them before running the vertical pipe up through the blocking it would have been a pain to do later.  The one you see below will be covered with a bench seat at the dining room table.  In case of a plumbing emergency the cushion can be taken off the seat and a hinged panel will provide access to the cleanout.

For a contractor, calling the plumber out before the entire house is framed is unusual.  I’m sure they would have been able to come up with a solution without breaking their routine, but I’m also pretty sure it wouldn’t have been as neat and efficient as my solution.  For me, it was very easy to stop framing for half the day and work on some plumbing so that I could finish with the blocking.  Yet another great example of the flaws in building a house with contractors…