If you want to spend the money you can make your perimeter insulation continuous, remember the code is only a minimum. Inspect the vapor barrier prior to the pour, and fix any tears or holes in it.

Don't get cheap with the amount of sand and pea-gravel around and over the drain tile, plus you can double or triple the drain tile placement like they do in some earth sheltered homes.

How tall is the elevated slab? My first rule of thumb when building a house is where will the water go. Make sure it's tall enough to be able yo build up the grade around it and force water away from the house.

Yea raise the slab above grade (see your local code), the swells around the house along with a good roof overhang and or downspouts leading away from the house can prevent a lot of problems.

Per the builder:
The elevated slab will raise the house 16" above grade.
All downspouts are to drain 6ft from house, min.

I designed a two car garage with an elevated slab once (sloping site). The sub-contractor was complaining about how much re-bar my structural engineer put in there and that I had re-bar in spots "doing nothing". I held to the design despite his claims that he had gotten away with half as much re-bar on other projects.

Years later a builder client of mine purchased a house with a detached (elevated slab) garage. First thing I asked was, did he build it and how his elevated slab was holding up. He said; funny you should ask, first thing we had to do when we bought the house was raise up the garage and install new supporting walls and concrete floor as they were falling apart with our wood workshop in there. They ended up doubling the re-bar over what someone put in before.

I have no idea if the same contractor was involved, but it is a small world.

Having a structural engineer check the re-bar design might be a good idea. There is nothing rule of thumb or conventional about it.

Is this over kill?

http://forums.pelicanparts.com/uploa...1270758727.jpg




260 tons of concrete to support our clock tower project 140' high est.http://forums.pelicanparts.com/uploa...1270759027.jpg
http://forums.pelicanparts.com/uploa...1270759042.jpg
http://forums.pelicanparts.com/uploa...1270759055.jpg
http://forums.pelicanparts.com/uploa...1270759071.jpg

^^^^. Whoa whoa whoa! They just going to pour that on the dirt? Where are the formboards to hold it in?

There's something really wrong going on there....








:)

They said they poured on clay. If that means dirt, yep I guess they did. Here are some more pics.




http://forums.pelicanparts.com/uploa...1270823153.jpg
http://forums.pelicanparts.com/uploa...1270823181.jpg
http://forums.pelicanparts.com/uploa...1270823200.jpg
http://forums.pelicanparts.com/uploa...1270823215.jpg

It seems like there are some vertical pieces or rebar, but do you think the plastic vertical spacers are degradable?