Garbage greenhouse: Framing and raising the walls

Toe plate, 2012, Jeremy Sandrik: Toe plates for stud walls are anchored to the concrete foundation with lag screws, lag shields, and washers.  A strip of tar paper separates the toe plate from the concrete pad.

A couple of weeks ago, I described the planning and design (scroll way down if you want to get right to the 3D rendering) process behind the garbage greenhouse composed of repurposed materials.  In the last few posts, I've been pretty verbose in supplying justification for my work on the greenhouse and garden in terms of energy conservation and food security.  This week, I'll simply share how the greenhouse has moved forward since its last mention here.

If you're new here, I'll very briefly outline some key features of the greenhouse.

• Pressure treated 2"x4" pine frame
• Repurposed windows on east, south, and 3/4 of west walls
• Repurposed glass bottles embedded in concrete on north and 1/4 of west walls
• Repurposed solid wooden door
• Repurposed windows on south roof face
• Repurposed material, still unknown and unobtained, on north roof face

Since my last post, I've had a few offers of material for the northern roof face.  I have a roll of donated tar paper (thanks, Dave) that will cover the required area (~72 sq. ft.), an offer of asphalt roll roofing (thanks, Blair) that I've yet to collect, and an offer of asphalt shingles (thanks, Mary Sue) that I've yet to collect.  As I'd done with the windows, I'll simply keep collecting material and make a decision once I've got it all in front of me.  In any event, any or all of the mentioned materials would be applied over OSB or plywood nailed to the roof rafters.

As far as actual progress that required the use of hands, I spent about three days last week nailing the wooden frame together for the south, east, and west walls.  For the time being, there is no frame to speak of for the north wall, which I'll address further down.  Last Saturday, with the help of some friends, we raised the walls into position, anchored them to the existing concrete pad foundation, and nailed them to each other.  For those attempting a similar project, I'll provide some process detail.

Framing 1, 2012, Jeremy Sandrik: Using a tape, framing square, and pencil to mark stud locations on the toe plate

Framing 2, 2012, Jeremy Sandrik: Using cordless, compressorless framing nailer to assemble frame.  Cinderblocks present for support

First, the south wall was placed on the foundation and measured to ensure it was parallel with the foundation's edge.  Using a hammer drill, 5/8-inch holes were bored in the bottom plate and roughly 3 inches into the concrete pad, spaced roughly every 27 inches (give or take a few inches to accommodate irregularities in the concrete surface).  The wall was then temporarily moved to insert lead lag shields into the concrete.  A strip of tar paper was then placed over the holes, the wall placed back over the tar paper, and lag screws with washers were tightened down to anchor the wall.

The process was repeated with both the east and west walls.  We took advantage of a carpenter's trick, the 3-4-5 right triangle, to square up the walls before anchoring them to the concrete.  Briefly, here's how you do it.

1. Bring your walls together and measure 3 feet from the intersection along one wall and mark it with a pencil.
2. Measure 4 feet from the intersection along the other wall and mark it with a pencil.
3. Measure between your two pencil marks.  If the walls are square, the measurement will equal 5 feet.  If the measurement doesn't equal 5 feet, pivot the unanchored wall until the marks are 5 feet apart.
4. Note that this works with multiples of 3-4-5, like 6-8-10.

Once the walls were square, we drilled our holes, inserted the lag shields, and anchored with lag screws.  Then, the end studs of the two intersecting walls were nailed together, and nails were driven down through the overlapping top plates.

I'm sure an experienced carpenter could have done the job in an hour alone or with a pair of helping hands.  All told, we took about 2 1/2 hours with 8 novice hands.

Greenhouse wall frame, SW corner, 2012, Jeremy Sandrik: East, south, and west walls framed and erected.  Note overlapping top plates in the corner, and bracing added on south wall.

Thus, the east, south and west walls were framed and anchored.  The only wooden component of the north wall will eventually be a double top plate supported by the glass bottle and concrete wall, with the top plate overlapping those of the east and west walls for additional stability.  The north top plate will be laid once the bottle wall is complete.

That brings me to a frustrating grind to a halt in the construction process.  It's not recommended by the manufacturers to work with concrete in sub-freezing temperatures.  Sure, our daytime highs have been warm enough, but our nights are still plunging into low 30s and high 20s.  Even above 50°F, the curing time is up to 7 days.  That said, I'll be waiting at least a week before I can move forward on the bottle wall.  Further, the roofing needs to rest on the north wall, and I'd prefer to have the roof frame in place before applying the window skin to the east, south, and west walls.  Consequently, I'd rather not move forward attaching windows to the anchored walls.  Anxious to do something, I added some additional studs in the corners where the walls intersect, and some braces between studs on the south wall, as the frame was just a bit wiggly for my taste if I'd left it as designed.

Despite the fact that this project is framed and unlikely to deviate from the plan at this point, I'm always interested to see how other people do it.  It was encouraging when a friend dropped by to see what I've been doing and say, "I hadn't thought of that."  If you've got a greenhouse and you're in the Keweenaw, even if you're not, I'd love to see it and kibitz about the design and function.  Drop me a comment or a link in the comments or by email, if you like.  As always, thanks for reading.