Footings under existing slab.
Pouring concrete under existing wall.
2 i have tested several types of bags.
Pour an interior wall.
I would also pour concrete higher than the existing deck in order for you to slope the top of the pour i m order to shed water.
3 that video above with the guy putting steel in the bags is my video.
4 i can disprove your theory that the concrete will not set up correct due to water ratios.
And if a wall is chipping or crumbling it s fair to say the bag was taken off way to early.
This may require jacking up the car port to accommodate.
If you re not overly concerned about seams in your slab you can notch out sections of your floor under your walls and pour footing sections to support the wall partially then remove the rest of the wood floor and pour the rest of your slab use re bar extended past through the forms of your first footing sections so they can be tied into the main slab.
Pour the concrete in small sections spreading the concrete by moving the chute back and forth and by having the driver pull forward as you go.
This allows the homeowner to use the.
Once the truck has reached the end of a section spread the concrete out evenly and a touch higher than the form with a concrete placer rake.
1 i have been doing these walls for 30 years.