Solar Power Day 15
Concrete slabs are literally designed to come apart at the seams? Curious...
Like yesterday, today started off quiet with no sign of anyone. I was really hoping the solar crew would show up again with the full team to finish things up today, but as with most things construction related, things didn’t go according to plan. What did go according to plan was the concrete crew arriving to do a final inspection and cut the seams in the slab. Everything passed with flying colors (an ironic choice of words considering the slab is technically monochrome) so the team of two set about marking the seams with a chalk line and then cutting.
I liked how this saw had the little wheel in front to follow chalk lines
Cuts where seams met like this where done with an angle grinder and a diamond blade
With that the concrete slab is complete and after a little under an hour of work the concrete crew departed.
For anyone that is curious about why these seams exist they are to create deliberate weak points in the slab to aid in cracking. The only time the slab will have the most even weight distribution will be when it is first poured since the ground is leveled prior to pouring, but it will never be quite the same after this point. The ground moves during frost and thaw periods throughout the seasons, causing the concrete slab to move with it as well as changes in the support underneath the slab. Thus there will eventually and inevitably be an area that isn’t sufficiently supported anymore and the slab will eventually break as a result. The seams create controlled weak points so that when the ground moves up and down and takes the slab with it, instead of the slab cracking all the way through to the top in a random pattern, the seam breaks and the section of the slab moves independently of the rest of the slab. This is why you sometimes see driveways, patios, and walkways with uneven seams - the concrete at that seam has already broken and the two (or more) sections are moving independent of each other. Long term this can still be rectified by using mud jacking or poly leveling.
To my surprise the solar crew once again returned at 3PM with my solar engineer eventually making an appearance. Like yesterday, more panels were bolted down to the pergola roof.
The final panel in the lower right corner of the picture above was left unsecured. Not exactly sure why, but I imagine I’ll find out when the crew next returns.
The progress for which I don’t have pictures is the house roof, though there isn’t anything to show. The remaining rigging from the panels relocated away from my kitchen skylights was removed, however a small bit of patchwork still needs to be done. The final panel on the house also still needs to be mounted.
While that was going on the solar engineer, the remaining crew, and I worked to get a tree taken down in the middle of my western side yard. This tree was both just tall enough to cause shade over a decent amount of the western panels, but was also dead, so there was no reason to keep it around. My solar engineer had an electric chainsaw with him, which he used to cut off the branches, but this only proved effective until he couldn’t reach any higher. So I grabbed my electric pole saw and gave him a temporary upgrade. There is always something to be said for having the right tool for the job.
As branches were cut the crewmembers originally working on the pergola roof carried the branches down to the back edge of my backyard where there is an old fire pit. We probably won’t burn these branches here, though, due to the fire pit being right next to the tree line. I did buy a new raised fire pit for the pergola during a Black Friday sale, so I will likely be dragging these branches back uphill in the future, after cutting them down to size of course.
Most of the branches were cut down by the time it was too dark to continue working, but the trunk in its entirety is still standing. My solar engineer left his ladder and a rope tied to the tree for when he next returns to bring the rest of the tree down.
Because the crew was only here for a little over two hours, they didn’t shut down my power and complete the interconnection. Hopefully that will happen when they return on Monday.
And with that another day in this project and this week have come to a close. Time for dinner, a bit of gaming or TV, and a lot of relaxation. See you next time.