Building Codes - Sheetrock

We're being told by a builder that they only have to put one coat of mud on the tape in corners of closets.  The tape peels or there are ridges so the tape is very visible.  Where can we find the Missouri codes to get this person to provide what we asked for - a quality custom built home?

I don't know that there is a local building code for that issue.  Building codes address mostly 'life and safety' issues.  The only reference to joint treatment in the Uniform Building Code is as it relates to fire safety in Gypsum Wallboards.  You may want to look into recommended practices published by the drywall association.  Another good source is usually the manufacturer of the tape and/or the mud used (or any tape or mud - check the label for phone or address).  They have their recommendations on the proper use of their product.  Find their technical department and get either a specification sheet or recommended practice. If you have a problem locating any of those let me know.  I would also like to know what you find.