Hot answers tagged rebuild
They sell extenders just for this. They come in metal, aluminum, plastic, different thickness for many applications, single gang, double, etc... Visit the electrical aisle of your home improvement store.
I've thought about doing the same thing (adding on an upstairs to my house). One of the simple problems is permits; the inspection offices want to deal with things they know, and building above an unknown. Basically, your support comes from below; the new floor rests on the floor below, and the floors below on the foundation. If you need stronger walls, ...
I'd have to agree with @Tester101 that without actually seeing the site, there is no real way to tell you if what you plan can be done, but one data point: my brother looked into adding a floor to his house, and the estimate he got was a lot more than he paid for the house 5 years earlier. I can easily believe that it would be cheaper in the long run to ...
The concrete itself should be fine. Make sure water doesn't have anywhere it can pool, since standing water, concrete, and freezing temperatures can lead to cracking. I would protect any metal brackets or bolts intended to secure the framing to the foundation. And I would also protect any plumbing coming through the foundation. Where the water line is ...
You could build over, rather then upwards using a metal frame, then just connect the two independent structures at the stairs. You will need a very good engineer, but at least there will be very few unknowns as the new frame could even sit on separate foundations outside of your current foundations.
You can also buy tabs (outlet shims) that interlock together to extend the box out. Used often for tile (I believe they are sold in the tile and electrical sections at Lowes). If what you're doing results in the outlet/switch sticking out further than the box though, then the above would be the way to go.
a picture would help, but i sense that no matter what i will recommend you to use cob - that is, building with earth. i didn't understood exactly what gap you need to fill but cob can fill everything, it's cheap (cost nothing!) it's fixable, and it can stand the heat (with guaranty - in the past i have built some ovens with it).
Only top voted, non community-wiki answers of a minimum length are eligible