Answer: 46 inches Explanation: Residential interior floors are typically 4" thick in standard exposure situations, thickening up to 24" for load bearing in turndowns, grade beams, or thickened slab locations. 
Maven Group LLC 
Answer: 46 inches Explanation: Its the average standard for strength and durability of concrete for its purpose. 
BAT Concrete llc 
Answer: 46 inches Explanation: This aplies to non post tension slabs which are 10 inches 
Concrete Designs 

ProMatcher 
Answer: 46 inches Explanation: Standard concrete floor slab thickness in residential construction is 4 inches. Five to six inches is recommended if the concrete will receive occasional heavy loads, such as motor homes or garbage trucks. 
Colorado Concrete 
Answer: 46 inches Explanation: Normal slab for residential structure would be 4". There are grade support beams through the slab also. 
Design4 
Answer: 46 inches Explanation: 4 usually is ok , but if there is load bearing walls that will be framed on new slab then thickened slab or footing needs to installed. 
Concrete services 

ProMatcher 
Answer: 46 inches Explanation: 4 inches except for perimeter which should be a 8 inch minimum 
DIRTCO CONSTRUCTION 
Answer: 46 inches Explanation: Residential concrete slabs should always be poured at 4 to 5 inches with compacted fill and footers at blueprint spec,to avoid any sinkholes in the future. 
Lals Concrete Company,LLC 
Answer: 46 inches Explanation: 4""
is sufficient 
LPG,LLC 

ProMatcher 
Answer: 24 inches Explanation: Residential concrete slabs are typically 4" 
Concrete & Beauty Design 
Answer: 46 inches Explanation: Sometimes 8 inches and with wire mash 
Garcias Concrete Service 