New Slab Over Existing Stemwall

[CBSE]

Working on a pretty simple wood building that was originally a remodel to be a new gym and physical therapy building. Stemwalls and footings, floor joists with crawl space, and wood walls and trusses. Just a small rectangle (5,000 sqft). The original building was built in the 1970's. I actually have the original plans.

My original suggestion to the owners and architect was to tear the building down and build a new one because the original was in such structural dispair that the fixes would be too costly and they wanted to keep the same floor system against my recommendations. Well, after (3) design iterations with trying to salvage the original building, we are now completely torn down.

They are now wanting to do a slab on grade and place the slab over the stemwalls. I have attached a detail of what I think is appropriate to do for this. Thoughts? I don't know if the stemwall was built per the plans, so I have went a bit conservative on reinforcing and tying things in.

 

[KootK]

That's about what I'd do. There's some reinforcing in the SOG though right? Called out on plan maybe?

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[CBSE]

Yes. There will be reinforcing there. Probably #4's @ 18-24" o.c. depending on slab thickness. May even go welded wire fabric.

 

[KootK]

Excellent. Casting the slab against existing concrete with dowels is likely to produce some shrinkage cracking in the vicinity. No big deal, I just wouldn't do unreinforced SOG there.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[CBSE]

Good point! This has been the oddest project I have ever been involved with in terms of iterations. This is the 4th iteration so hopefully a fork is stuck in it. Although, they previously commented about going up with a second story....ugh.

 

[KootK]

And I'm sure that you're getting paid for every second of rework...

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[CBSE]

Wouldn't that be nice!!! Actually, there were a couple of minor changes initially that I just did for them initially thinking that I could start building a bit of a relationship. It was a new client, first job with them, actually. After I spent about 2.5-3 hrs doing very minor adjustments for them I came to realize very quickly that this was not a client I want to pursue long term. The architect is terrible at responding to e-mails and phone calls, would update his drawings mid-stream after sending me a background set to use and not have the decency to send new ones and then ask why things were a certain way (major changes in window sizes and locations). After that first 2.5-3 hrs I started billing them and rounding to the nearest 1/2hr. Sometimes it just doesn't work out. Oh well.