Thanks in advance for taking the time to read this. I'll try to keep it brief :wink2: My hubby and I own a 24 x 28 cabin in the mtns of northern Wyoming which needs lots of work. It's basically the shell of a tiny house right now. The original osb subfloor has extensive water damage. It will hold weight but is obviously warped and needs to go. It currently has a pier foundation under it consisting of pressure treated beams and basically concrete deck blocks. The crawl space is narrow, 12-14" , but I've managed to get under it and checked and the bottom looked in good shape. No visible termite, water, or rodent damage. My concern is that it's not just the subfloor thats warped. That maybe the blocks have settled over time or due to the frost(it gets down to -40 up in the mountains) and will worsen with added weight. Also the soil is dry and a mix of red clay and lava rock.
My question is this--- after I rip the floor up, would it be more prudent to dig and pour new concrete piers(mind you I'd have to dig past Wyoming's 60" frost line) OR should I reinforce and leave the old piers and maybe add concrete block and insulation to make a kind of shallow frost protected foundation of sorts ...???? Is mortar and block better than just plain block by itself? What would be the best option in the long run?
Any advice or recommendations are greatly appreciated!!!
Are there any other signs of major settling or movement? Do the doors/wiindows work. Major cracks or anything inside? Obviously, frost footings are ideal, but holy smokes is that a lot of back breaking work. So if you don't see a lot of evidence of settling/heaving, I'd question whether it would be worth it in the end. There are plenty of little cabins that aren't on real foundations. Now if you were going to add on to it, or add a story, or sink a pile of money into it, that would be a different thing.
Frost protected footings do work, but the rub is that you have to bury the foam, typically 4' out from each post. Doesn't work to just lay it on the ground.
If you really wanted to add a foundation, you could jack it up high enough so you could fit some equipment under there. Or do like a friend of mine did and build a foundation next to his little house on piers, and built ramps and used coffin hoists to winch the house onto the foundation.
Or you can do what I did with my little cabin. I poured 16" x 16" x 6" pads dug just below the organic layer and put blocks on them. This has worked well, though it a very forgiving site--a well drained gravel knoll. All me doors work, no cracks in the sheetrock, and it helps out my property taxes:smile: