Concrete work & kitchen countertop — Part 2

The work on the concrete foundations for the future garage extension, and on the laminated kitchen countertop have been going on concurrently, so this post updates those two projects.  The weather has gotten even hotter here lately — every summer hotter than the last — and now we're in a string of days with highs around 100˚.  So happy I got the new heating/cooling system in last winter!  A/C works great!  But these two projects are outdoors (or in the garage) :-(  So work some, go in to cool down, repeat.

While the digging was going on, I gravitated toward the much more pleasant countertop lamination.  In the last post, I described the building of the flat and level glue-up frame.  When that was done, I used the table saw to make strips out of 3/4" thick maple, cherry, and walnut boards, a little over one inch wide.  These were turned on edge and arranged on my gluing frame. 

Initially, I planned to do the whole countertop in maple, with just two walnut stripes.  But then cherry came in, and I ended up with more strips of both walnut and cherry, so I just started arranging them until I ended up with something I thought I would not tire of over a decade or two. 

I put the plywood undermount sink template (that I had made some time ago) on top of the strips so I could see where I didn't need wood, since the opening would be cut away when the countertop was all laminated.  I am laminating the rough countertop to be thirteen feet long; the ends will be cut off square to a finished length of 12.5 feet.  Ideally, I would have thirteen-foot long boards, but most of my strips are at most ten feet long, so by cutting them to skip the holes for the sink and the cooktop cutouts, one ten-foot board could span the whole thirteen-foot long countertop blank.  (The pictures may explain that better.)

I am using a West System marine epoxy to laminate all the strips together, and will also put a couple of coats of epoxy on the finished countertop for complete waterproofing and stability.  I'm using biscuits to align the strips during the gluing process (inserted into matching slots in adjacent strips).  The working time for the two-part epoxy I was using is about 25 minutes.  I set a kitchen timer so I would know when I had to start clamping the strips together (lest the epoxy start to set up, and everything thrown away).  I managed to glue five strips together for the first batch, using twelve clamps.

For that first batch, I brushed the epoxy on each strip individually, and then mated it to the next strip, and so on.  For the second batch, I arranged the strips against each other so I could brush the epoxy on a number of strips at the same time.  Much faster. 

Once the strips are glued together, they have to be planed flat and smooth, because of the glue runout and, well, because the strips are never going to be perfectly aligned.  The kitchen countertop is 30" deep, while my thickness planer has a 12" width capacity.  So I'm laminating the countertop in three sections, each between ten and eleven inches wide.  Each section goes through the planer separately.  Then the three sections will be carefully aligned and glued together.  When the strips are clamped together, the epoxy gets squeezed out the top, but mostly out the bottom.  I can scrape off the excess glue from the top before it hardens, but not from the bottom, so the first passes through the planer need to take the glue off the bottom.

Lots of space needed to get the long countertop section through the planer:

The second section is done pretty much the same as the first section, although the strips for the second section have to be clamped to the first section (but not glued yet), so the second section will be a perfect match to the first section.  There are slight variations in the thickness of the strips which means that even if the first strip was perfectly straight, the last strip in a section will not be.  Once the strips are glued together to form a 10" wide section, no amount of clamping will bend them to conform to the adjacent section, unless they were clamped together during the gluing process.

For the first section, I could use my six 12" clamps and my six 24" clamps.  For the second 10" section, clamped to the first section, the 12" clamps would not work.  So out came my 48" clamps to supplement my 24" clamps.  Can't do a project like this without a lot of clamps.

Here's a look at the first two sections sitting side-by-side, after preliminary planing (all three sections will get a final fine planing to bring them to the same thickness before being glued together).  The overall view, showing the cooktop cutout and the more distant sink cutout:

And a closer view.  When coated with epoxy, the colors will be darker and more saturated, and the plan is to sand the epoxy to a satin finish.

As for the third section, I need to make the hour drive down to the hardwood store to buy more wood before countertop work resumes.  Work has shifted to the concrete.

I finally finished digging the trench into the rock-hard ground.  Again, the deeper trench is for the footings, and the forms for the 24" stem wall will sit, more or less, on the outer shallower trench.

The trenchworks had to be fairly precisely located, straight, square, and at the proper depth.  To ensure the right depth for upper and lower trenches, I used a small laser level, along with a stick marked with the various depths.  The laser level sat on the garage floor on a purpose-built box as a reference height.

And then I started building the stem wall forms, in sections, attaching them together, positioning, adjusting elevation, etc.  At this point all the outer wall sections are in place.  Now I need to start putting the rebar in, and then build and install the inner sections of the forms.  Then tie them together, shim them level, stake them in place.  Then concrete!

Update . . .

Work on the new concrete foundation for the garage extension has been slow, so I'm doing an update, rather than wait for what could be months (or years) until the project is done.  First, it took some time to get a company here to remove the part of the old concrete driveway directly in front of the garage.  Second, the ground underneath was something like asphalt in hardness, so digging has been slow (and in discovering a way to blast through it, I did a bad thing to my usually robust lower back — which halted digging for almost a week).  And third, it's been hot here, and unusually humid, so I've limited my daily excavating work.

Here's how the concrete removal went.  First, sawing up the concrete with a big diamond saw:

And then, breaking up the concrete with a monster jack hammer mounted on a Bobcat:

Which produced a lot of rubble that was loaded into a big dump truck:

And by lunchtime, it was all gone!

I then mounted a big tarp over the work area to provide some shade for my digs:

Meanwhile, I designed the foundation, the stud wall that will go on top (details of which were needed to locate the anchor bolts in the foundation wall), then I designed the forms to be used to pour the concrete.  The footings, foundation wall, and form design dictated the depth and size of the trench required.  I bought a laser level to make sure the depth was accurate all around the future wall, and then after laying out the dimensions on the ground with string, proceeded to dig (or tried to dig).

I started with a mattock (a type of pick with a flat blade), but that mostly just bounced off the rock-like soil.  Then attacked it with my 20-pound electric demolition hammer, using a three-inch wide bit.  That cut through the petrified dirt.  Here is a photo of my digs:

And a better photo of the trench.  The deeper narrower trench (16" wide, and 8+" deep) is for the footings.  This lower trench will contain the concrete without the need for separate wooden forms, possible because of the hard ground.

The wooden forms will sit on top of the deeper trench, supported by the wide shelf of the upper trench.  The foundation wall will be 24" high and 8" thick.  The concrete for both footings and foundation wall will be poured on the same day, with a break to pour the new front porch slab.  That will give the footings time to start firming up before filling the foundation wall forms to the top.

So now more digging to do, and forms to build.

Because the heat makes digging difficult, I have started on the less taxing kitchen countertop fabrication project, working on both projects every day.  That works well because I can't put my car in the garage until the concrete work is done, and the countertop project fills the garage.  The countertop is, again, going to be an epoxy lamination of maple strips.  The countertop is 12.5 feet long, and 30" deep.  I've just finished building the form on which the gluing will be done (lots of clamps will be required).  It's 13 feet long, and needed to be precisely level and flat, so the countertop will emerge from gluing perfectly flat and straight, and therefore fit without issues on the kitchen cabinet.  The jig/form looks like this:

So next post will likely feature these two projects.

Sasha, most recently rescued stray: