I am doing close cell they start praying next week 4” ceiling and 3” wall that puts me at r33 in ceiling and r22 In walls to total of 46k shop is 42x96. That price from January went up 18k in 6 months. Still spray foam is a better product. Also Dug out footing for my loft last minute just thinking what your going through glad i did. Only Dug out where all support walls will be and went larger in column areas.
That's an impressive jump in price for the foam. My ceiling will be R-30 in the ceiling and R-23 in the walls if the county allows us to continue like we want. Spray foam has a lot of great advantages. Mineral wool fits my use case better in this instance.
You likely have saved yourself time and frustration by digging out those footings at the last minute.
What a royal pain! Why are they considering the wall load-bearing? If I recall correctly, my plans called for thicker concrete pads under those interior loft supporting posts. I also don't have any walls, so the deck is designed for the span from post to post and the posts take all the load.
I need to add more insulation in the ceiling like you are doing. Does the mineral wool stay in place on its own or are there straps I can't see? Are you going to cover it with something?
78SC4X4, our plans are designed by the same contractor and engineer and share the loft design in common. The GC has handled all communication so far so I don't know exactly why they consider the interior walls to be load bearing. I noticed that you didn't have any problems in this regard. My building also has thicker concrete at the loft posts and they have concrete footings with an engineering note that it is for a loft.
the 2 interior walls are floating on those posts and the floor joists are oriented to act as a cantilever for the stair landing and transfer load to those same posts. Essentially I could dig new footings right now under the walls and neither the walls nor the second story would be compromised because they are being held up by the interior and exterior posts.
The mineral wool doesn't need any extra support when it goes up. No straps. It's much stiffer than fiberglass and doesn't sag over time like fiberglass. I'll have the same 29 gauge liner panel on the ceilings and most walls as the exterior siding. I opted for nailed down solid hardwood flooring on the back wall and loft floor in combination with the mineral wool four better sound acoustics. All of that metal siding and roofing reverberates a lot. Mineral wool is the best insulation material for sound absorption. It cuts real easy also. Here are some more closeup pics that might help.


Yeah we have had record breaking rain this year so I think the water tables are very high. Hopefully this upcoming dry weather will help you.
Water table! That's the word I was looking for. Thanks.