Your shouldn't be declaring variables inside of a loop. It's bad practice.
... it's also bad forum practice to start two topics stating two questions on the same code. Just ask another question in the same topic.
Here is your code with a prompt added. I also changed a few logical errors.
int tiles; /* tile size in inches */
printf("Enter the size of the tiles in inches > ");
printf("Enter the room width (feet and inches seperated by a space): ");
scanf("%d %d", &wid_feet, &wid_inch);
printf("Enter the room length (feet and inches separated by a space): ");
scanf("%d %d", &length_feet, &length_inch);
width_total = (wid_feet * 12) + wid_inch;
room_tile = ceil(width_total / tiles);
length_total = (length_feet * 12) + length_inch;
length_tile = ceil(length_total / tiles);
total_tiles = room_tile * length_tile;
printf("The %d'%d width and %d' %d length room requires %d, %d inch tiles\n\n",
wid_feet, wid_inch, length_feet, length_inch, total_tiles, tiles);
getchar(); // Eats the \n in the stream. Sorry I forgot that. :)
printf("Do you have another room you wish to enter? (y/n) \n >");
if ( cont != 'Y' && cont != 'y' && cont != 'N' && cont != 'n' )
printf("Please enter \"y\" or \"n\". \n");
} while ( cont != 'Y' && cont != 'y' && cont != 'N' && cont != 'n' );
} while (cont == 'Y' || cont == 'y');