Thursday, January 16, 2014

Limestone blocks for the raised garden

With the concrete footing for the raised garden poured, we can now compute how much limestone we need to finish the project.  The concrete has been poured to be level all the way around.  It's not perfect, but pretty close -- we will use a bed of mortar on the bottom course to even things out.  At the deepest point, it is about 16 inches below the pathway surface.  If the blocks are 6x6, that means 3 courses will be below ground level at this point.  We want the garden to be raised about the same as before, which would be 16 inches.  So that means about 32 inches, or 5 courses total.

Each course is 10 feet deep by 16 feet long, so 52 linear feet per course, and with 5 courses, that would be 260 linear feet.  At 6x6, that would be 65 cubic feet.  I measured pallets, and they seem to be about 31 inches by 48 inches by 40 inches, or 33 cubic feet. So I need two pallets.  And then I could go get individual pieces if I need more.

We bought the two pallets at Whittlesey Landscape Supplies.  The two pallets of stone were 7460 pounds of 6x6 dry stack for $535.35.  A cubic yard of decomposed granite was $57.93.  With another $90 for delivery.  6 bags of mortar from Home Depot.

We moved all this around back, laid out a string line to define the rectangle that should be where the stones go and started laying them out. Once they were laid out, mortar was put on the concrete footing, and the stones put on that, to try to get things level.

After this has a chance to dry, we put another layer of stone on top of this for the second course.

And a third course.

And a fourth course.

The rock debris that was inside the raised garden, was put out for Craig's List or used to fill in the pathway around the raised garden.  Once that was filled in, decomposed granite was put over it, to create a smooth surface.

We still have to mortar this fourth course, but this seems to work pretty well.

There is a significant slope from left to right (North to South).

Another half cubic yard of decomposed granite from Whittlesey Landscape supplies -- this time I borrowed a pick-up rather than have it delivered. $20.84, on 15 Feb 2014.

The gaps between the stones on the top (4th) course worried me.  But if I filled them up, I would want to make it "like" the limestone.  I found that there is "white mortar", so I bought a bag (50 lbs) of that (Home Depot).  It is about 4 times more expensive than regular mortar, but it is much closer to "white", like the limestone.  I filled all the vertical gaps for the 4th course of stone, so that dirt and bugs and stuff will not sink down into that.

In addition, I used the left-over mortar to smear on the inside of the walls, giving a sort of plaster sealed finish on the inside.