Expert: Dan Griffin - 10/17/2008

Question
My builder has agreed to remove and replace the suspended L shape concrete slab in our house.  Should a structural engineer be involved here?  I'm thinking so as the builder is trying to use his own guys and there are still a lot of questions on how to go about the removal of the slab and construction of the new one.  Can you suggest how we should go about doing this?  How can we minimize damage to the rest of the completed house.  The footings appear to be fine and will be supporting the slab.  
I appreciate your help, I have asked you questions regarding this slab when I was concerned about whether it had rebar (which it doesn't) and the leaks that were difficult to repair.

Answer
I can't imagine anyone having poured a weight bearing suspended slab without reinforcement.  I think everyone involved will be more confident in the end result to involve a structural engineer.  As you have noted, the removal will be quite an undertaking, perhaps the hardest part.  A local structural engineer who can see the situation will make much more sense than any armchair quarterbacking on the internet.

The concrete will need to have sufficient control and construction joints with major attention to waterproofing issues.  It can be done, but going to an alternate deck system may be a better long tern choice.