My concrete block stemwall is falling apart

[_RaT_]

The way California makes us build schools is to pour the footing to 1" below the bottom plate and then dry pack the space. This will insure full contact. The hard part on a completed structure like your is that someone will have to go under and back up the packing.

The drypack has to be rammed pretty tight to be effective. Usually a 3/4" board and a hammer.

You know Jim, that makes a lot of sense. Really the only way to ensure tight interface between the sill and the top of the concrete.

 

[Egon]

Jack up the building and block it. Form and pour concrete. wait for a week or so and lower building down.

 

[CurlyDave]

...The sill will require upgraded attachment. 5/8" bolts with the large square washers. Biggest issue I see is pouring the concrete in a form that is tight to the mudsill. In other words, how do I get the concrete in the form and how do I ensure it is filled up to the sill. A friend in the construction business said they make a upside down pyramid hopper, hand feed the concrete and vibrate the form.

If I had to do this job, I would support the building, Maybe jack it up a little, and then drill the mudsills and place new 5/8" foundation bolts on about 16" centers, this looks and sounds like way overkill, but I would put galvanized nuts and the 3" square washers both above and below the mudsills. Tighten them up pretty well, to squeeze the musdill between them. Maybe even add a new PT mudsill below the existing one.

Now add your rebar and form up. Use a 6 or 7 sack mix intended for a pump and vibrate the heck out of the form. Rent a professional vibrator for this, don't even think about hammering the form ... it will not do the job. Pour with as wet a mix as you can get away with to achieve the requisite strength, which the engineer will specify for you.

The foundation bolts will be capable of providing either tension or compression loads in the double nut & double washer configuration. This will allow some tolerance in getting the concrete to completely fill the void between the mudsill and the footer below.