Building new shack on an old slab?

[ADK_XJ]

Hey all, I know it's the off-season but I'm hoping some of the real know-it-alls (in the best way possible) are still plugged in...I've been planning to start a shack build in September on an old (1960s) 12 x 16 concrete slab. Thing is, I hadn't really looked at it closely after we bought the property a year ago and have had it covered with foam pallets and last year's firewood since then.

Now that I've started uncovering the concrete I'm noticing cracks in the corners...anyone think this is salvageable? Would love to think I patch it up with some masonry adhesive and go on my way but don't want to build a shed and then rebuild it a few years later. Keep in mind it took it 65 years to get to this point, pictures below:

11855

11856

[MISugarDaddy]

I know concrete isn't cheap (poured 17 yards of it this spring) but it is going to be the most important part of your new building. Have you considered using the existing slab for your wood storage? When we built our new sugarhouse, we used the previous slab where we had the evaporator for constructing our wood storage area. For a 12' by 16' sugarhouse, you are only going to need 2.5 yards of concrete, and that will cost somewhere around $250 if you use a 6 sack mix.
Gary

[SeanD]

I built my sugar house on an existing slab and I had to do some work on it to shore it up. Have the building inspector come out and take a look. The advice will be free, you'll know you'll get the final sign-off, and you'll have the peace of mind that your work won't collapse under a snow load right before the sugaring season. Besides, you'll need the inspector's ok for it to be insured.

Even if you do get the ok, I recommend pouring a footing for your evaporator. That looks like a floating slab which could been fine for another 100 years, but the problem I ran into was some of the ground is shifting under the slab and now I have cracks right next to the firebox. I can tell a hollow spot is opening up underneath. I'm in the process of moving the evaporator to refab a footing for it. Moving a bricked evaporator is a total pain, so I recommend you do it now while it's easy.

Sean