My sugarhouse is all hemlock except for the pressure treated (PT) posts. No issue. Screw or nail using twisted nails for better grip. A twisted nail has super grip, but I prefer screws. If Jamaica Cottage deals with good saw mills, they will not have shake. Shake can be seen while still in the log and a good mill will then only use that for low grade applications like pallet boards and such, or even shred it for mulch. In my entire sugarhouse I only ended up with one 2x4 with shake.
Shake is when the growth rings come apart.
Hemlock has many advantages, it can get wet a lot without rotting and it can actually hold up to some ground contact, but by no means like PT lumber. The strength of hemlock lumber is a lot more than pine, the pine in the kit will likely only be trim boards.
Dave Klish, I recently ordered a 2x6 wood fired evaporator from A&A Sheet Metal which I will be converting to oil fired
Now have solar, 2x6 finish pan, 5 bank 7x7 filter press, large water jacketed bottler, and tankless water heater.
Recently bought another Gingerich RO, this one was a 125, but a second membrane was added thus is a 250, like I had.
After running a 2x3, a 2x6, 3x8 tapping from 79 taps up to 1320 all woodfired, now I'm going to a 2x6 oil fired and a 200-425 taps.